{"id":4533,"date":"2026-09-16T11:15:26","date_gmt":"2026-09-16T03:15:26","guid":{"rendered":"https:\/\/cnkuangya.com\/?p=4533"},"modified":"2026-09-16T11:15:30","modified_gmt":"2026-09-16T03:15:30","slug":"3-1-vs-4-0-spd","status":"publish","type":"post","link":"https:\/\/cnkuangya.com\/ja\/blog\/3-1-vs-4-0-spd\/","title":{"rendered":"3+1\u65b9\u5f0f\u30684+0\u65b9\u5f0f\u306eSPD\uff1a\u9055\u3044\u3001\u914d\u7dda\u3001\u304a\u3088\u3073\u9078\u5b9a\u30ac\u30a4\u30c9"},"content":{"rendered":"<p class=\"wp-block-paragraph\">3+1\u69cb\u6210\u30684+0\u69cb\u6210\u306eSPD\u306e\u6bd4\u8f03\u306f\u3001\u5916\u89b3\u304b\u3089\u59cb\u307e\u308b\u3053\u3068\u304c\u3088\u304f\u3042\u308a\u307e\u3059\u3002\u3069\u3061\u3089\u3082DIN\u30ec\u30fc\u30eb\u30e2\u30b8\u30e5\u30fc\u30eb\u30924\u3064\u5360\u6709\u3059\u308b\u5834\u5408\u3001\u5916\u898b\u4e0a\u306f\u307b\u307c\u540c\u4e00\u306b\u898b\u3048\u308b\u305f\u3081\u3067\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3057\u304b\u3057\u3001\u96fb\u6c17\u7684\u306a\u7279\u6027\u306f\u540c\u4e00\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e3b\u306a\u9055\u3044\u306f\u3001 <strong>\u30b5\u30fc\u30b8\u4fdd\u8b77\u7d4c\u8def\u3067\u3059\u3002<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u822c\u7684\u306a3+1\u69cb\u6210\u306e\u30b5\u30fc\u30b8\u4fdd\u8b77\u30c7\u30d0\u30a4\u30b9\u306f\u3001\u76f8\u5c0e\u4f53\u304b\u3089\u4e2d\u6027\u7dda\uff08N\uff09\u3078\u5411\u304b\u30463\u3064\u306e\u4fdd\u8b77\u7d4c\u8def\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1 \u2192 N<\/strong><br><strong>L2 \u2192 N<\/strong><br><strong>L3 \u2192 N<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8ffd\u52a0\u306e\u4fdd\u8b77\u7d4c\u8def\u304c1\u3064\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>N \u2192 PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u822c\u7684\u306a4+0\u69cb\u6210\u3067\u306f\u3001\u76f4\u63a5PE\u306b\u57fa\u6e96\u5316\u3055\u308c\u305f\u4fdd\u8b77\u7d4c\u8def\u304c\u63d0\u4f9b\u3055\u308c\u307e\u3059\u3002\u901a\u5e38\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1 \u2192 PE<\/strong><br><strong>L2 \u2192 PE<\/strong><br><strong>L3 \u2192 PE<\/strong><br><strong>N \u2192 PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u9055\u3044\u306f\u3001\u7dda\u9593\u3001\u4e2d\u6027\u7dda\u3001\u4fdd\u8b77\u63a5\u5730\u9593\u306b\u304a\u3051\u308b\u30b5\u30fc\u30b8\u96fb\u5727\u306e\u5236\u5fa1\u65b9\u6cd5\u306b\u5f71\u97ff\u3059\u308b\u305f\u3081\u3001 <strong>3+1\u69cb\u6210\u30684+0\u69cb\u6210\u306f\u3001\u30e2\u30b8\u30e5\u30fc\u30eb\u6570\u3084\u6975\u6570\u3060\u3051\u3067\u9078\u629e\u3059\u3079\u304d\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u6b63\u3057\u3044\u69cb\u6210\u306f\u3001\u63a5\u5730\u30b7\u30b9\u30c6\u30e0\u3001\u5fc5\u8981\u306a\u4fdd\u8b77\u30e2\u30fc\u30c9\u3001\u8a2d\u7f6e\u5834\u6240\u3001\u304a\u3088\u3073SPD\u30e1\u30fc\u30ab\u30fc\u304c\u898f\u5b9a\u3059\u308b\u5b9f\u969b\u306e\u5185\u90e8\u56de\u8def\u306b\u3088\u3063\u3066\u6c7a\u307e\u308a\u307e\u3059\u3002.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>\u30af\u30a4\u30c3\u30af\u30a2\u30f3\u30b5\u30fc\uff1a<\/strong> 3+1\u306fTT\u30b7\u30b9\u30c6\u30e0\u3067\u4e00\u822c\u7684\u306b\u4f7f\u7528\u3055\u308c\u3001TN-S\u30b7\u30b9\u30c6\u30e0\u3067\u3082\u5229\u7528\u53ef\u80fd\u3067\u3059\u30024+0\u306f\u9069\u5207\u306aTN-S\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u3067\u4e00\u822c\u7684\u306b\u4f7f\u7528\u3055\u308c\u307e\u3059\u3002\u3059\u3079\u3066\u306e4\u6975SPD\u304c\u96fb\u6c17\u7684\u306b\u540c\u7b49\u3067\u3042\u308b\u3068\u60f3\u5b9a\u305b\u305a\u3001\u5fc5\u305a\u914d\u7dda\u56f3\u3068\u9069\u7528\u3055\u308c\u308b\u8a2d\u7f6e\u8981\u4ef6\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002.<\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">3+1 SPD\u30684+0 SPD\u306e\u6982\u8981<\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u7279\u5fb4<\/th><th>3+1 SPD<\/th><th>4+0 SPD<\/th><\/tr><\/thead><tbody><tr><td>\u4ee3\u8868\u7684\u306a\u76f8\u4fdd\u8b77\u7d4c\u8def<\/td><td>L1-N, L2-N, L3-N<\/td><td>L1-PE, L2-PE, L3-PE<\/td><\/tr><tr><td>\u4e2d\u6027\u7dda\u4fdd\u8b77<\/td><td>N-PE\u5206\u96e2\u7d4c\u8def<\/td><td>4\u6975\u69cb\u6210\u306e\u4e00\u90e8\u3068\u3057\u3066\u306eN-PE\u7d4c\u8def<\/td><\/tr><tr><td>\u6a19\u6e96\u7684\u306a\u5185\u90e8\u8a2d\u8a08<\/td><td>L-N\u9593\u306eMOV \uff0b N-PE\u9593\u306e\u30b9\u30a4\u30c3\u30c1\u30f3\u30b0\u7d20\u5b50\/GDT<\/td><td>PE\u3092\u57fa\u6e96\u3068\u3057\u305f\u96fb\u5727\u5236\u9650\u7d20\u5b50\uff08\u4e00\u822c\u7684\uff09<\/td><\/tr><tr><td>\u76f4\u63a5\u7684\u306aL-N\u4fdd\u8b77<\/td><td>\u306f\u3044<\/td><td>\u5c02\u7528\u306eL-N\u8981\u7d20\u3067\u3042\u308b\u5fc5\u8981\u306f\u306a\u3044<\/td><\/tr><tr><td>\u76f4\u63a5\u7684\u306aL-PE\u7d4c\u8def<\/td><td>\u5354\u8abf\u3055\u308c\u305fL-N + N-PE\u7d4c\u8def\u7d4c\u7531<\/td><td>\u306f\u3044<\/td><\/tr><tr><td>\u4e00\u822c\u7684\u306a\u9069\u7528<\/td><td>TT\u30b7\u30b9\u30c6\u30e0\u304a\u3088\u3073\u4e00\u90e8\u306eTN-S\u30b7\u30b9\u30c6\u30e0<\/td><td>TN-S\u30b7\u30b9\u30c6\u30e0<\/td><\/tr><tr><td>\u7269\u7406\u30e2\u30b8\u30e5\u30fc\u30eb<\/td><td>4\u6975\uff084P\uff09\u304c\u4e00\u822c\u7684<\/td><td>4\u6975\uff084P\uff09\u304c\u4e00\u822c\u7684<\/td><\/tr><tr><td>\u300c4P\u300d\u3068\u540c\u3058\u3067\u3059\u304b\uff1f<\/td><td>\u81ea\u52d5\u7684\u3067\u306f\u3042\u308a\u307e\u305b\u3093<\/td><td>\u81ea\u52d5\u7684\u3067\u306f\u3042\u308a\u307e\u305b\u3093<\/td><\/tr><tr><td>\u9078\u5b9a\u306e\u4e3b\u306a\u57fa\u6e96<\/td><td>\u63a5\u5730\u65b9\u5f0f + \u914d\u7dda\u56f3 + \u5b9a\u683c<\/td><td>\u63a5\u5730\u65b9\u5f0f + \u914d\u7dda\u56f3 + \u5b9a\u683c<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u6700\u3082\u91cd\u8981\u306a\u70b9\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>4\u3064\u306e\u30e2\u30b8\u30e5\u30fc\u30eb\u304c\u898b\u3048\u308b\u304b\u3089\u3068\u3044\u3063\u3066\u3001\u305d\u306eSPD\u304c3+1\u69cb\u6210\u304b4+0\u69cb\u6210\u304b\u3092\u898b\u5206\u3051\u308b\u3053\u3068\u306f\u3067\u304d\u307e\u305b\u3093\u3002.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u5fc5\u305a\u7d50\u7dda\u56f3\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">3+1\u69cb\u6210\u30684+0\u69cb\u6210\u306eSPD\u3092\u9078\u5b9a\u3059\u308b\u9375\u306f\u3001\u5358\u306b\u76ee\u306b\u898b\u3048\u308b\u30e2\u30b8\u30e5\u30fc\u30eb\u306e\u6570\u3092\u6570\u3048\u308b\u3053\u3068\u3067\u306f\u306a\u304f\u3001\u5185\u90e8\u306e\u4fdd\u8b77\u7d4c\u8def\u3092\u7406\u89e3\u3059\u308b\u3053\u3068\u3067\u3059\u3002.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">SPD\u306b\u304a\u3051\u308b\u300c3+1\u300d\u3068\u306f\u3069\u3046\u3044\u3046\u610f\u5473\u3067\u3059\u304b\uff1f<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u822c\u7684\u306a\u4e09\u76f84\u7dda\u5f0f\u306b\u304a\u3044\u3066 <strong>3+1\u69cb\u6210\u306eSPD<\/strong>, 3\u76f8\u5c0e\u4f53\u306f\u4e2d\u6027\u7dda\u306b\u5bfe\u3057\u3066\u4fdd\u8b77\u3055\u308c\u3066\u3044\u307e\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4fdd\u8b77\u7d4c\u8def\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u4fdd\u8b77\u8981\u7d20<\/th><th>\u7d4c\u8def<\/th><\/tr><\/thead><tbody><tr><td>\u8981\u7d201<\/td><td>L1 \u2192 N<\/td><\/tr><tr><td>\u8981\u7d202<\/td><td>L2 \u2192 N<\/td><\/tr><tr><td>\u8981\u7d203<\/td><td>L3 \u2192 N<\/td><\/tr><tr><td>\u8ffd\u52a0\u8981\u7d20<\/td><td>N \u2192 PE<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path-1024x576.jpg\" alt=\"3+1 SPD wiring showing L1 L2 L3 to neutral and N to PE protection\" class=\"wp-image-4535\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path-1024x576.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path-300x169.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path-768x432.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path-1536x864.jpg 1536w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path-18x10.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path-600x338.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-spd-wiring-protection-path.jpg 1672w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">\u4e00\u822c\u7684\u306a3+1\u69cb\u6210\u306eSPD\u306f\u30013\u3064\u306e\u76f8\u9593\u30fb\u4e2d\u6027\u7dda\u9593\u4fdd\u8b77\u7d4c\u8def\u30681\u3064\u306eN-PE\u9593\u4fdd\u8b77\u7d4c\u8def\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u6700\u521d\u306e3\u3064\u306e\u4fdd\u8b77\u7d20\u5b50\u306f\u3001\u4e00\u822c\u7684\u306b\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u96fb\u5727\u5236\u9650\u30c7\u30d0\u30a4\u30b9\u3067\u3059\u3002 <strong>MOV\uff08\u91d1\u5c5e\u9178\u5316\u7269\u30d0\u30ea\u30b9\u30bf\uff09<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u8ffd\u52a0\u306eN-PE\u9593\u4fdd\u8b77\u7d20\u5b50\u306f\u3001\u4e00\u822c\u7684\u306b\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u3082\u306e\u3067\u3059\u3002 <strong>\u30b9\u30d1\u30fc\u30af\u30ae\u30e3\u30c3\u30d7\u307e\u305f\u306f\u30ac\u30b9\u653e\u96fb\u7ba1\u30d9\u30fc\u30b9\u306e\u30b9\u30a4\u30c3\u30c1\u30f3\u30b0\u7d20\u5b50<\/strong>, \uff08\u88fd\u54c1\u8a2d\u8a08\u306b\u3088\u3063\u3066\u7570\u306a\u308a\u307e\u3059\uff09\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, KUANGYA&#8217;s <a href=\"https:\/\/cnkuangya.com\/ja\/product\/vsp3s40-type2-ac-spd\/\">3+1\u30bf\u30a4\u30d72 AC SPD<\/a> L1\/L2\/L3\u3068N\u306e\u9593\u306b3\u3064\u306eMOV\u4fdd\u8b77\u7d4c\u8def\u3092\u4f7f\u7528\u3057\u3001N\u3068PE\u306e\u9593\u306bGDT\u4fdd\u8b77\u7d4c\u8def\u3092\u7d44\u307f\u5408\u308f\u305b\u3066\u3044\u307e\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u30eb\u30b0\u30e9\u30f3\u793e\u3082\u540c\u69d8\u306b\u30013P+N \/ 3+1\u69cb\u6210\u306b\u3064\u3044\u3066\u3001L-N\u9593\u304a\u3088\u3073N-PE\u9593\u306e\u4fdd\u8b77\u3092\u63d0\u4f9b\u3057\u3001\u4e2d\u6027\u6975\u306f\u5bc6\u9589\u578b\u653e\u96fb\u7ba1\u306b\u3088\u3063\u3066\u4fdd\u8b77\u3055\u308c\u3066\u3044\u308b\u3068\u8aac\u660e\u3057\u3066\u3044\u307e\u3059\u3002.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u7c21\u7565\u5316\u3055\u308c\u305f3+1\u69cb\u9020<\/h3>\n\n\n\n<pre class=\"wp-block-code\"><code>L1 \u2500\u2500&#91;MOV]\u2500\u2500\u2510\nL2 \u2500\u2500&#91;MOV]\u2500\u2500\u2524\nL3 \u2500\u2500&#91;MOV]\u2500\u2500\u2524\u2500\u2500 N \u2500\u2500&#91;GDT \/ switching element]\u2500\u2500 PE\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">This is a simplified illustration. The actual internal circuit and protective technology must always be confirmed from the manufacturer&#8217;s datasheet.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">SPD\u306b\u304a\u3051\u308b\u300c4+0\u300d\u3068\u306f\u4f55\u3092\u610f\u5473\u3057\u307e\u3059\u304b\uff1f<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u5178\u578b\u7684\u306a\u4f8b <strong>4+0 SPD<\/strong> \u4fdd\u8b77\u63a5\u5730\uff08PE\uff09\u3092\u57fa\u6e96\u3068\u3057\u305f4\u3064\u306e\u4fdd\u8b77\u7d4c\u8def\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u822c\u7684\u306a\u69cb\u6210\u306f\u4ee5\u4e0b\u306e\u901a\u308a\u3067\u3059\uff1a<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>L1 \u2500\u2500&#91;SPD]\u2500\u2500 PE\nL2 \u2500\u2500&#91;SPD]\u2500\u2500 PE\nL3 \u2500\u2500&#91;SPD]\u2500\u2500 PE\nN  \u2500\u2500&#91;SPD]\u2500\u2500 PE\n<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path-1024x576.jpg\" alt=\"4+0 SPD wiring showing L1 L2 L3 and neutral protection to PE\" class=\"wp-image-4536\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path-1024x576.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path-300x169.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path-768x432.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path-1536x864.jpg 1536w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path-18x10.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path-600x338.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/4-0-spd-wiring-protection-path.jpg 1672w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">\u4e00\u822c\u7684\u306a4+0\u69cb\u6210\u306eSPD\u306f\u3001PE\u3092\u57fa\u6e96\u3068\u3057\u305f\u500b\u5225\u306e\u4fdd\u8b77\u7d4c\u8def\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u69cb\u6210\u3067\u306f\u30013\u76f8\u304a\u3088\u3073\u4e2d\u6027\u7dda\u306e\u305d\u308c\u305e\u308c\u304cPE\u306b\u5411\u304b\u3046\u4fdd\u8b77\u7d4c\u8def\u3092\u6709\u3057\u3066\u3044\u307e\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, KUANGYA&#8217;s VSP1S40 4+0 model is intended for TN-S systems and provides L-PE and N-PE protection modes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">DEHN\u793e\u3082\u540c\u69d8\u306b\u30014\u3064\u306e\u7d4c\u8def\u3092\u6301\u3064TN-S\u30e2\u30c7\u30eb\u3092\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u5b9a\u7fa9\u3057\u3066\u3044\u307e\u3059\u3002 <strong>4+0\u69cb\u6210<\/strong>, \u4e00\u65b9\u3067\u3001TT\u30b7\u30b9\u30c6\u30e0\u304a\u3088\u3073TN-S\u30b7\u30b9\u30c6\u30e0\u5411\u3051\u306b\u3001\u500b\u5225\u306e3+1\u88fd\u54c1\u3082\u63d0\u4f9b\u3057\u3066\u3044\u307e\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u305f\u3060\u3057\u3001\u3053\u306e\u70b9\u306b\u3064\u3044\u3066\u306f\u8cfc\u5165\u6642\u306b\u6ce8\u610f\u304c\u5fc5\u8981\u3067\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u30e1\u30fc\u30ab\u30fc\u306b\u3088\u3063\u3066\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u7528\u8a9e\u304c\u4f7f\u7528\u3055\u308c\u308b\u5834\u5408\u304c\u3042\u308a\u307e\u3059\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>4P<\/strong><br><strong>3P+N<\/strong><br><strong>4+0<\/strong><br><strong>3+1<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u30ab\u30bf\u30ed\u30b0\u306e\u30bf\u30a4\u30c8\u30eb\u306b\u304a\u3044\u3066\u3001\u308f\u305a\u304b\u306b\u7570\u306a\u308b\u65b9\u6cd5\u3067\u4f7f\u7528\u3055\u308c\u308b\u3053\u3068\u304c\u3042\u308a\u307e\u3059\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3057\u305f\u304c\u3063\u3066\uff1a<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>\u88fd\u54c1\u540d\u3060\u3051\u3067\u5185\u90e8\u306eSPD\u30c8\u30dd\u30ed\u30b8\u30fc\u3092\u5224\u65ad\u3057\u306a\u3044\u3067\u304f\u3060\u3055\u3044\u3002\u56de\u8def\u56f3\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">3+1\u30684+0\uff1a\u672c\u5f53\u306e\u9055\u3044\u306f\u4f55\u3067\u3059\u304b\uff1f<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u672c\u5f53\u306e\u9055\u3044\u306f\u30e2\u30b8\u30e5\u30fc\u30eb\u306e\u6570\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u305d\u308c\u306f <strong>\u30b5\u30fc\u30b8\u96fb\u5727\u304c\u3069\u3053\u3067\u5236\u5fa1\u3055\u308c\u3001\u30b5\u30fc\u30b8\u96fb\u6d41\u304c\u3069\u3053\u3078\u9003\u304c\u3055\u308c\u308b\u304b\u3068\u3044\u3046\u70b9\u3067\u3059\u3002<\/strong>.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram-1024x576.jpg\" alt=\"3+1 vs 4+0 SPD wiring diagram comparison\" class=\"wp-image-4539\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram-1024x576.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram-300x169.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram-768x432.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram-1536x864.jpg 1536w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram-18x10.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram-600x338.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-wiring-diagram.jpg 1672w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">3+1\u30684+0\u306eSPD\u69cb\u6210\u306b\u304a\u3051\u308b\u6c7a\u5b9a\u7684\u306a\u9055\u3044\u306f\u3001\u76ee\u306b\u898b\u3048\u308b\u30e2\u30b8\u30e5\u30fc\u30eb\u306e\u6570\u3067\u306f\u306a\u304f\u3001\u5185\u90e8\u306e\u30b5\u30fc\u30b8\u4fdd\u8b77\u7d4c\u8def\u306b\u3042\u308a\u307e\u3059\u3002.<\/figcaption><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\">3+1\u69cb\u6210<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">3+1\u69cb\u6210\u306f\u3001\u4ee5\u4e0b\u306e\u9593\u3092\u76f4\u63a5\u4fdd\u8b77\u3057\u307e\u3059\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1-N\u9593<\/strong><br><strong>L2-N\u9593<\/strong><br><strong>L3-N\u9593<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u7d9a\u3044\u3066\u3001\u4ee5\u4e0b\u306e\u9593\u306b\u72ec\u7acb\u3057\u305f\u7d4c\u8def\u3092\u8a2d\u3051\u307e\u3059\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>N-PE\u9593<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u308c\u306b\u3088\u308a\u3001\u76f8\u3068\u4e2d\u6027\u7dda\u306e\u9593\u306b\u63a5\u7d9a\u3055\u308c\u305f\u8ca0\u8377\u306b\u5bfe\u3057\u3066\u3001\u76f4\u63a5\u7684\u306a\u7dda\u9593\u30fb\u4e2d\u6027\u7dda\u9593\u4fdd\u8b77\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">4+0\u69cb\u6210<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u4e00\u822c\u7684\u306a4+0\u914d\u7f6e\u306f\u3001\u6d3b\u7dda\u5c0e\u4f53\u3068PE\uff08\u4fdd\u8b77\u63a5\u5730\uff09\u3068\u306e\u9593\u306b\u76f4\u63a5\u7684\u306a\u4fdd\u8b77\u3092\u63d0\u4f9b\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1-PE<\/strong><br><strong>L2-PE<\/strong><br><strong>L3-PE<\/strong><br><strong>N-PE\u9593<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The line-to-neutral voltage may also be influenced during a surge through the combined operation of protection elements, but this is not the same topology as providing a dedicated L-N protective element.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is why two SPDs with:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>four modules,<\/li>\n\n\n\n<li>the same Uc,<\/li>\n\n\n\n<li>the same In,<\/li>\n\n\n\n<li>and the same Imax<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">can still have very different internal circuits.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Common Mode vs Differential Mode Surge Protection<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u7406\u89e3\u3059\u308b <strong>common-mode and differential-mode surge voltage<\/strong> makes the 3+1 vs 4+0 difference easier to understand.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Differential-mode surge<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A differential-mode surge appears between active conductors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u3092\u6319\u3052\u3088\u3046\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L-N<\/strong><br><strong>L1-L2<\/strong><br><strong>L2-L3<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a single-phase load connected between L and N, the L-N voltage is particularly important.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A typical 3+1 topology provides a direct L-N protective path.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Common-mode surge<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A common-mode surge appears between an active conductor and earth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u4f8b\u3092\u6319\u3052\u3088\u3046\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1-PE<\/strong><br><strong>L2-PE<\/strong><br><strong>L3-PE<\/strong><br><strong>N-PE\u9593<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Lightning-induced transients can create significant common-mode voltage relative to earth.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A typical 4+0 configuration provides direct active-conductor-to-PE paths.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A 3+1 configuration handles the surge through its coordinated L-N and N-PE protection network.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, when comparing SPDs, asking:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201cHow many poles does it have?\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">is less useful than asking:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>\u201cWhich protection modes does it provide?\u201d<\/strong><\/p>\n<\/blockquote>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode-1024x576.jpg\" alt=\"SPD common mode vs differential mode surge protection paths\" class=\"wp-image-4540\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode-1024x576.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode-300x169.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode-768x432.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode-1536x864.jpg 1536w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode-18x10.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode-600x338.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/spd-common-mode-vs-differential-mode.jpg 1672w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Differential-mode surges occur between active conductors, while common-mode surges occur between active conductors and earth.<\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Why Does a 3+1 SPD Use a Separate N-PE Element?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">This is one of the most important differences buyers notice when opening a 3+1 SPD.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The N-PE module may look different from the three L-N modules.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is not necessarily a manufacturing inconsistency.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It may use a different protection technology because it performs a different electrical function.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In many 3+1 designs:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L-N = MOV<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">while:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>N-PE = GDT or spark-gap-based element<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">DEHN, for example, offers dedicated N-PE spark-gap arresters intended for 1+1 and 3+1 configurations in TT systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">KUANGYA&#8217;s Type 2 3+1 AC SPD similarly uses MOV protection between the phases and neutral, with a GDT between neutral and PE.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">One advantage of a suitable switching N-PE element is that it does not create the same continuous leakage path between N and PE as a permanently voltage-limiting element might.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, the exact technology, follow-current capability, TOV behavior and ratings remain product-specific.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Never assume that every 3+1 SPD uses exactly the same internal components.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">3+1 or 4+0 SPD for a TT System?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">For 3+1 vs 4+0 SPD selection, the earthing system is one of the most important factors to confirm. For a typical IEC-based TT earthing system, a 3+1 configuration is widely used.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In a TT system:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>the supply neutral is earthed at the source;<\/li>\n\n\n\n<li>the installation has its own protective-earth arrangement;<\/li>\n\n\n\n<li>N and PE remain separate within the installation.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">A 3+1 SPD provides:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1 \u2192 N<\/strong><br><strong>L2 \u2192 N<\/strong><br><strong>L3 \u2192 N<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">plus:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>N \u2192 PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This topology is commonly used to coordinate surge protection with the TT earthing arrangement.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">DEHN&#8217;s technical guidance shows the 3+1 circuit for TT systems, and current DEHN products are specifically offered for TT and TN-S installations using this configuration.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">But do not use one sentence as a universal rule<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">It is tempting to remember:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">TT = 3+1<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">That is useful as a starting point, but it is not a complete SPD specification.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">You must still check:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>installation location,<\/li>\n\n\n\n<li>position relative to the RCD,<\/li>\n\n\n\n<li>local electrical regulations,<\/li>\n\n\n\n<li>system voltage,<\/li>\n\n\n\n<li>Uc\u3001<\/li>\n\n\n\n<li>Up,<\/li>\n\n\n\n<li>In \/ Imax \/ Iimp,<\/li>\n\n\n\n<li>short-circuit conditions,<\/li>\n\n\n\n<li>\u30d0\u30c3\u30af\u30a2\u30c3\u30d7\u4fdd\u8b77,<\/li>\n\n\n\n<li>and the manufacturer&#8217;s connection diagram.<\/li>\n<\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">3+1 or 4+0 SPD for a TN-S System?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">TN-S systems have separate:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>N \u2014 Neutral<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u305d\u3057\u3066<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PE \u2014 Protective Earth<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">conductors.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Both 3+1 and suitable 4+0 products can be found for TN-S applications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, DEHN currently offers:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><a href=\"https:\/\/www.dehn-international.com\/en\/products\/red-line\/dehnguard-md\" rel=\"noopener\">4+0 products specifically for TN-S<\/a><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u305d\u3057\u3066\uff1a<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong><a href=\"https:\/\/www.dehn-international.com\/en\/products\/red-line\/dehnguard-md\" rel=\"noopener\">3+1 products for TT and TN-S systems<\/a>.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">KUANGYA follows a similar product distinction: the VSP1S40 4+0 version is specified for TN-S, while the corresponding 3+1 configuration is available for TT and TN-S systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Therefore, it is not technically correct to say:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201cTN-S always needs 4+0.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u307e\u305f\u306f\uff1a<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201c3+1 is only for TT.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Instead, the required protection modes, installation rules and manufacturer-approved configuration should determine the selection.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"852\" height=\"1024\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0-852x1024.jpg\" alt=\"TT and TN-S earthing systems with 3+1 and 4+0 SPD configurations\" class=\"wp-image-4541\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0-852x1024.jpg 852w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0-250x300.jpg 250w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0-768x923.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0-10x12.jpg 10w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0-300x361.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0-600x721.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/tt-vs-tns-spd-3-1-4-0.jpg 1144w\" sizes=\"auto, (max-width: 852px) 100vw, 852px\" \/><figcaption class=\"wp-element-caption\">3+1 is commonly used in TT systems and is also available for TN-S, while suitable 4+0 products are commonly used in TN-S applications.<\/figcaption><\/figure>\n\n\n\n<h1 class=\"wp-block-heading\">What About TN-C and TN-C-S Systems?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">This is where pole-count mistakes become particularly common.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">TN-C<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In a TN-C section of an installation, neutral and protective-earth functions are combined in a single:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>PEN conductor<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A typical three-phase arrangement therefore uses:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1-PEN<\/strong><br><strong>L2-PEN<\/strong><br><strong>L3-PEN<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">often described as a <strong>3+0 configuration<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">There is no separate N conductor and PE conductor at that point, so a separate N-PE protection path would not describe the conductor arrangement correctly.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">TN-C-S<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A TN-C-S installation contains two different sections.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Before the PEN conductor is separated:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>TN-C principles apply.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">After PEN is separated into:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>N + PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">the downstream section behaves as TN-S.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3057\u305f\u304c\u3063\u3066\uff1a<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>The correct SPD configuration depends on where the SPD is installed relative to the PEN separation point.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Do not select a 3P or 4P SPD simply because the overall building supply is described as TN-C-S.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Check the actual conductor arrangement at the SPD installation point.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">How Can You Tell Whether an SPD Is 3+1 or 4+0?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The easiest way to identify a 3+1 vs 4+0 SPD configuration is to check the manufacturer&#8217;s wiring diagram rather than count the cartridges.<\/p>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"960\" height=\"1024\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd-960x1024.jpg\" alt=\"How to identify 3+1 and 4+0 SPD from wiring diagram\" class=\"wp-image-4542\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd-960x1024.jpg 960w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd-281x300.jpg 281w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd-768x819.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd-11x12.jpg 11w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd-300x320.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd-600x640.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/how-to-identify-3-1-4-0-spd.jpg 1214w\" sizes=\"auto, (max-width: 960px) 100vw, 960px\" \/><figcaption class=\"wp-element-caption\">The wiring diagram is more reliable than the module count when identifying 3+1 and 4+0 SPD topology.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Look at the wiring diagram.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">A typical 3+1 diagram shows:<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>L1 \u2500\u2500 SPD \u2500\u2500 N\nL2 \u2500\u2500 SPD \u2500\u2500 N\nL3 \u2500\u2500 SPD \u2500\u2500 N\nN  \u2500\u2500 SPD \u2500\u2500 PE\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Look for three phase-to-neutral paths plus one neutral-to-earth path.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The N-PE element may also have a different symbol from the L-N elements.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">A typical 4+0 diagram shows:<\/h2>\n\n\n\n<pre class=\"wp-block-code\"><code>L1 \u2500\u2500 SPD \u2500\u2500 PE\nL2 \u2500\u2500 SPD \u2500\u2500 PE\nL3 \u2500\u2500 SPD \u2500\u2500 PE\nN  \u2500\u2500 SPD \u2500\u2500 PE\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">Look for four protection paths referenced toward PE.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Buyer tip<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">When requesting a quotation, do not write only:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">\u201cNeed 4P SPD.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Instead, provide:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u30b7\u30b9\u30c6\u30e0\uff1a<\/strong> AC230\/400 V<br><strong>Earthing system:<\/strong> TT \/ TN-S \/ TN-C \/ TN-C-S<br><strong>Required SPD type:<\/strong> Type 1 \/ Type 2 \/ Type 1+2<br><strong>Topology:<\/strong> 3+1 \/ 4+0 if known<br><strong>Uc:<\/strong> required value<br><strong>In \/ Imax \/ Iimp:<\/strong> required values<br><strong>Remote signal:<\/strong> \u306f\u3044\uff0f\u3044\u3044\u3048<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This greatly reduces the chance of receiving a product with the correct number of modules but the wrong internal connection.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Is a 3+1 SPD Better Than a 4+0 SPD?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Neither topology is universally \u201cbetter.\u201d<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They solve surge-protection paths differently.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A correctly selected 4+0 SPD can be appropriate for a suitable TN-S application.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A correctly selected 3+1 SPD can be appropriate for TT and suitable TN-S applications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The important question is not:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Which one is stronger?<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">\u6b63\u3057\u304f\u306f\u6b21\u306e\u901a\u308a\u3067\u3059\u3002<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Which topology matches the electrical network and the protection modes required at this installation point?<\/strong><\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">Performance must then be evaluated using the actual electrical specifications.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u308c\u3089\u306b\u306f\u6b21\u306e\u3088\u3046\u306a\u3082\u306e\u304c\u3042\u308b\uff1a<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u30d1\u30e9\u30e1\u30fc\u30bf<\/th><th>What to check<\/th><\/tr><\/thead><tbody><tr><td>\u30a6\u30af<\/td><td>\u6700\u5927\u9023\u7d9a\u4f7f\u7528\u96fb\u5727<\/td><\/tr><tr><td>\u4e0a\u3078<\/td><td>\u96fb\u5727\u4fdd\u8b77\u30ec\u30d9\u30eb<\/td><\/tr><tr><td>\u3067<\/td><td>\u516c\u79f0\u653e\u96fb\u96fb\u6d41<\/td><\/tr><tr><td>\u30a2\u30a4\u30de\u30c3\u30af\u30b9<\/td><td>Maximum discharge current for applicable Type 2 products<\/td><\/tr><tr><td>\u30a4\u30f3\u30d7<\/td><td>Lightning impulse current for applicable Type 1 products<\/td><\/tr><tr><td>Isccr \/ short-circuit rating<\/td><td>Compatibility with available fault current<\/td><\/tr><tr><td>Backup protection<\/td><td>Required fuse or circuit breaker<\/td><\/tr><tr><td>TOV performance<\/td><td>Behavior under temporary overvoltage<\/td><\/tr><tr><td>Remote contact<\/td><td>Whether remote monitoring is required<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Do not judge SPD performance simply by the largest kA number on the label.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Is 3+1 the Same as Type 3 + Type 1?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">\u305d\u3046\u3060\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is an easy naming mistake.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>3+1 describes the SPD protection topology.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It does not mean:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Type 3 + Type 1.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">If you are unsure about the difference between SPD classifications, see our guide to <strong><a href=\"https:\/\/cnkuangya.com\/ja\/%e3%83%96%e3%83%ad%e3%82%b0\/type-1-2-or-3-spd-where-to-place-them-for-optimal-solar-pv-and-ev-charging-protection\/\">Type 1, Type 2 and Type 3 SPDs<\/a><\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">SPD classification and topology are separate characteristics.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">AC power SPDs are covered by <strong><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/65314\" rel=\"noopener\">IEC 61643-11<\/a><\/strong>, which specifies performance and safety requirements, tests and ratings for surge protective devices connected to AC low-voltage power systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, a 3+1 SPD may be:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u30bf\u30a4\u30d71<\/strong><br><strong>\u30bf\u30a4\u30d72<\/strong><br>\u307e\u305f\u306f<br><strong>\u30bf\u30a4\u30d71+2<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">depending on its tested performance.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Likewise, a 4+0 product can also be offered in different SPD Types.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3057\u305f\u304c\u3063\u3066\uff1a<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>3+1 tells you how the protection paths are arranged. Type 1, Type 2 and Type 1+2 tell you about the SPD&#8217;s test classification and surge-current duty.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Can You Replace a 3+1 SPD With a 4+0 SPD?<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Not automatically.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Even if both products have:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>four modules,<\/li>\n\n\n\n<li>the same nominal voltage,<\/li>\n\n\n\n<li>the same Imax,<\/li>\n\n\n\n<li>and the same DIN-rail width,<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">their protection modes can be different.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Before replacing one topology with another, verify:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li>the earthing system;<\/li>\n\n\n\n<li>the installation point;<\/li>\n\n\n\n<li>L, N, PE and PEN arrangement;<\/li>\n\n\n\n<li>required protection modes;<\/li>\n\n\n\n<li>Uc;<\/li>\n\n\n\n<li>Up;<\/li>\n\n\n\n<li>In, Imax and\/or Iimp;<\/li>\n\n\n\n<li>short-circuit rating;<\/li>\n\n\n\n<li>backup protection;<\/li>\n\n\n\n<li>RCD coordination;<\/li>\n\n\n\n<li>manufacturer-approved wiring.<\/li>\n<\/ol>\n\n\n\n<p class=\"wp-block-paragraph\">The replacement should be based on the complete electrical design, not only mechanical compatibility.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Why Pole Count Alone Can Be Misleading<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Circuit breakers and SPDs should not be interpreted in exactly the same way.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A four-pole circuit breaker normally refers to conductors passing through switching\/protection poles.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">An SPD generally works <strong>in parallel with the circuit<\/strong> and provides a temporary low-impedance surge path.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">So \u201cfour-pole SPD\u201d does not automatically tell you everything about:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>internal protection elements;<\/li>\n\n\n\n<li>L-N protection;<\/li>\n\n\n\n<li>N-PE protection;<\/li>\n\n\n\n<li>MOV versus GDT technology;<\/li>\n\n\n\n<li>earthing-system compatibility;<\/li>\n\n\n\n<li>or SPD Type.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">If you are unfamiliar with this difference, see our guide <strong><a href=\"https:\/\/cnkuangya.com\/ja\/%e3%83%96%e3%83%ad%e3%82%b0\/why-spd-connected-in-parallel\/\">\u306a\u305cSPD\u306f\u76f4\u5217\u3067\u306f\u306a\u304f\u4e26\u5217\u306b\u63a5\u7d9a\u3055\u308c\u308b\u306e\u304b\uff1f<\/a><\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The circuit diagram remains more important than the number of visible modules.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">6 Common Mistakes When Choosing 3+1 and 4+0 SPDs<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 1: Choosing by the number of modules<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Four cartridges do not automatically mean a particular topology.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Check the internal diagram.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 2: Assuming every 4P SPD is 3+1<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A four-module product can use different internal protection arrangements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u201c4P\u201d and \u201c3+1\u201d should not be treated as synonyms without checking the manufacturer&#8217;s circuit.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 3: Assuming 3+1 is only for TT<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">3+1 products are widely used for TT, but manufacturers such as DEHN and KUANGYA also specify certain 3+1 products for TN-S systems.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 4: Ignoring the PEN split in TN-C-S<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The network arrangement before and after the PEN separation point is different.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Confirm where the SPD will actually be installed.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 5: Selecting by Imax alone<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">A 40 kA SPD is not automatically more suitable than a 20 kA product simply because the number is larger.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Topology, SPD Type, Uc, Up, In, Iimp, fault-current conditions and coordination must all be considered.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Mistake 6: Forgetting backup protection<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD&#8217;s surge-current rating is not the same thing as the rating of its backup fuse or circuit breaker.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Do not calculate:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\">Imax 40 kA = 40 A backup fuse.<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\">That is incorrect.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Backup protection must be selected according to the manufacturer requirements and the installation&#8217;s overcurrent and prospective short-circuit conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For a detailed explanation, see our guide <strong><a href=\"https:\/\/cnkuangya.com\/ja\/%e3%83%96%e3%83%ad%e3%82%b0\/spd-backup-fuse\/\">SPD\u30d0\u30c3\u30af\u30a2\u30c3\u30d7\u30d2\u30e5\u30fc\u30ba\uff1a\u9069\u5207\u306a\u9078\u5b9a\u306e\u305f\u3081\u306e7\u3064\u306e\u30eb\u30fc\u30eb<\/a><\/strong>.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Installation Still Matters After Choosing the Correct Topology<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">SPD selection and installation should also follow applicable requirements such as <strong><a href=\"https:\/\/webstore.iec.ch\/en\/publication\/104394\" rel=\"noopener\">IEC 60364-5-53<\/a><\/strong> and local electrical regulations.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Keep SPD connection conductors short<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">During a fast surge event, conductor inductance creates additional voltage.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Long or looped connecting wires can therefore increase the effective voltage reaching the protected equipment.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Use the shortest practical routing permitted by the installation design and applicable requirements.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Connect N, PE and PEN correctly<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Never create an unauthorized N-PE connection simply to make SPD wiring easier.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">This is particularly important in TT and TN-C-S systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The neutral, PE and PEN arrangement is part of the earthing system itself.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Check backup protection<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">The SPD manufacturer may specify:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>a maximum upstream fuse;<\/li>\n\n\n\n<li>a dedicated backup fuse;<\/li>\n\n\n\n<li>a circuit breaker;<\/li>\n\n\n\n<li>or conditions where existing upstream protection is sufficient.<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Follow the product data rather than estimating the backup device from In or Imax.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Consider RCD coordination<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In installations containing RCDs or RCCBs, SPD location and topology can affect the current path during transient or fault conditions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TT systems require particular attention to the relationship among:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>SPD + RCD + N + PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Follow the applicable installation rules and manufacturer guidance.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">3+1 vs 4+0 SPD Selection Checklist<\/h1>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"576\" src=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist-1024x576.jpg\" alt=\"3+1 vs 4+0 SPD selection checklist for TT and TN-S systems\" class=\"wp-image-4543\" srcset=\"https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist-1024x576.jpg 1024w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist-300x169.jpg 300w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist-768x432.jpg 768w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist-1536x864.jpg 1536w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist-18x10.jpg 18w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist-600x338.jpg 600w, https:\/\/cnkuangya.com\/wp-content\/uploads\/2026\/09\/3-1-vs-4-0-spd-selection-checklist.jpg 1672w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption class=\"wp-element-caption\">Correct SPD selection requires checking the earthing system, protection topology, voltage ratings and installation conditions.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Before ordering or approving an AC SPD, confirm the following:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u30c1\u30a7\u30c3\u30af<\/th><th>\u8cea\u554f<\/th><\/tr><\/thead><tbody><tr><td>\u30b7\u30b9\u30c6\u30e0\u96fb\u5727<\/td><td>Is it 230\/400 V, 120\/208 V or another system?<\/td><\/tr><tr><td>\u983b\u5ea6<\/td><td>50 Hz or 60 Hz?<\/td><\/tr><tr><td>\u63a5\u5730\u65b9\u5f0f<\/td><td>TT, TN-S, TN-C, TN-C-S or IT?<\/td><\/tr><tr><td>Installation point<\/td><td>Before or after the PEN split?<\/td><\/tr><tr><td>\u30cb\u30e5\u30fc\u30c8\u30e9\u30eb<\/td><td>Is N distributed at the SPD location?<\/td><\/tr><tr><td>PE\/PEN<\/td><td>Is the protective conductor PE or PEN?<\/td><\/tr><tr><td>\u30c8\u30dd\u30ed\u30b8\u30fc<\/td><td>3+0, 4+0, 3+1 or another configuration?<\/td><\/tr><tr><td>\u4fdd\u8b77\u30e2\u30fc\u30c9<\/td><td>L-N, L-PE, N-PE and\/or L-L?<\/td><\/tr><tr><td>SPD\u30bf\u30a4\u30d7<\/td><td>Type 1, Type 2 or Type 1+2?<\/td><\/tr><tr><td>\u30a6\u30af<\/td><td>Is the maximum continuous voltage suitable?<\/td><\/tr><tr><td>\u4e0a\u3078<\/td><td>Is the protection level suitable for downstream equipment?<\/td><\/tr><tr><td>\u30a4\u30f3 \/ \u30a2\u30a4\u30de\u30c3\u30af\u30b9<\/td><td>Are the Type 2 discharge ratings suitable?<\/td><\/tr><tr><td>\u30a4\u30f3\u30d7<\/td><td>If Type 1 is required, is Iimp specified?<\/td><\/tr><tr><td>Short-circuit rating<\/td><td>Is the SPD compatible with available fault current?<\/td><\/tr><tr><td>Backup device<\/td><td>Is the required fuse\/MCB confirmed?<\/td><\/tr><tr><td>TOV<\/td><td>Is temporary-overvoltage behavior specified?<\/td><\/tr><tr><td>Remote signal<\/td><td>Is remote monitoring required?<\/td><\/tr><tr><td>Wiring diagram<\/td><td>Has the actual manufacturer circuit been checked?<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A buyer who completes this checklist is much less likely to purchase the wrong SPD simply because two products look similar.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Example: Comparing Two Four-Module SPDs<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Consider two Type 2 AC SPDs.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">SPD A<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Four visible modules<\/li>\n\n\n\n<li>230\/400 V system<\/li>\n\n\n\n<li>In = 20 kA<\/li>\n\n\n\n<li>Imax = 40 kA<\/li>\n\n\n\n<li>3+1 topology<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Internal paths:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>L1-N\nL2-N\nL3-N\nN-PE\n<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\">SPD B<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Four visible modules<\/li>\n\n\n\n<li>230\/400 V system<\/li>\n\n\n\n<li>In = 20 kA<\/li>\n\n\n\n<li>Imax = 40 kA<\/li>\n\n\n\n<li>4+0 topology<\/li>\n<\/ul>\n\n\n\n<p class=\"wp-block-paragraph\">Internal paths:<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>L1-PE\nL2-PE\nL3-PE\nN-PE\n<\/code><\/pre>\n\n\n\n<p class=\"wp-block-paragraph\">From the front, these two devices may appear very similar.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Their surge-current ratings may even be identical.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">But their protection topology is different.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">That is why:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Same voltage + same kA + same number of modules does not mean the SPDs are electrically interchangeable.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">KUANGYA 3+1 and 4+0 AC SPD Options<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">KUANGYA offers a range of <strong><a href=\"https:\/\/cnkuangya.com\/ja\/ac-spd\/\">AC\u30b5\u30fc\u30b8\u4fdd\u8b77\u30c7\u30d0\u30a4\u30b9<\/a><\/strong> for different low-voltage distribution systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">For example, the VSP1S40 Type 2 series includes:<\/p>\n\n\n\n<figure class=\"wp-block-table\"><table class=\"has-fixed-layout\"><thead><tr><th>\u69cb\u6210<\/th><th>Typical network application<\/th><th>Protection arrangement<\/th><\/tr><\/thead><tbody><tr><td>3+0<\/td><td>TN-C<\/td><td>L-PEN<\/td><\/tr><tr><td>4+0<\/td><td>TN-S<\/td><td>L-PE \/ N-PE<\/td><\/tr><tr><td>1+1<\/td><td>TT \/ TN-S single phase<\/td><td>L-N + N-PE<\/td><\/tr><tr><td>3+1<\/td><td>TT \/ TN-S three phase<\/td><td>L1\/L2\/L3-N + N-PE<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">The 3+1 design uses high-energy MOV elements for the L-N paths together with a GDT in the N-PE path, while the 4+0 version uses a different protection arrangement suited to its declared network application.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">When requesting a model, provide the actual:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>network voltage + earthing system + SPD Type + required surge ratings + remote contact requirement<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">rather than ordering only by the number of poles.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">\u3088\u304f\u3042\u308b\u8cea\u554f<\/h1>\n\n\n\n<h2 class=\"wp-block-heading\">Is a 3+1 SPD a four-pole SPD?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Physically, a 3+1 SPD may use four positions or modules, but \u201c3+1\u201d describes the protection topology rather than merely the mechanical pole count.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Check the product wiring diagram.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is 3+1 better than 4+0?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Not universally.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The correct choice depends on the earthing system, required protection modes, installation rules and product design.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A correctly selected 4+0 device can be suitable for TN-S applications, while 3+1 is widely used in TT and also in suitable TN-S systems.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Why is the fourth module different in a 3+1 SPD?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">In many 3+1 designs, the three phase-to-neutral protection elements use MOV technology, while the N-PE path uses a GDT or spark gap.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The fourth module therefore performs a different electrical function.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Can I use a 3+1 SPD in a TN-S system?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Potentially, yes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Manufacturers including DEHN and KUANGYA offer 3+1 products declared for TT and TN-S applications. Final selection should still follow the product datasheet and applicable installation requirements.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Can I use a 4+0 SPD in a TT system?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Do not assume that a generic 4+0 product is suitable.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">TT systems require careful consideration of the protection arrangement, N-PE path, RCD location and applicable installation requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Use an SPD specifically declared by the manufacturer for the intended TT configuration.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Does 3+1 mean Type 3 + Type 1?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u305d\u3046\u3060\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">3+1 is a connection topology.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Type 1, Type 2 and Type 3 are SPD classifications associated with different test and application requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">They are separate concepts.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">Is a 4P SPD always a 4+0 SPD?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">\u305d\u3046\u3060\u3002.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Manufacturers may use terms such as 4P, 3P+N, 3+1 and 4+0 differently in short product descriptions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Always verify the internal wiring diagram and declared protection modes.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">What should I check first when choosing between 3+1 and 4+0?<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Start with the <strong>earthing system and actual conductor arrangement at the installation point<\/strong>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Then check:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>protection topology \u2192 SPD Type \u2192 Uc \u2192 Up \u2192 surge-current ratings \u2192 short-circuit conditions \u2192 backup protection \u2192 installation requirements.<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Do not start with the largest kA value.<\/p>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">\u7d50\u8ad6<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">The most important point in a 3+1 vs 4+0 SPD comparison is that the difference is not simply the number of modules.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A typical 3+1 SPD provides three phase-to-neutral protection paths plus a separate neutral-to-earth path:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1-N + L2-N + L3-N + N-PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">A typical 4+0 SPD instead provides four protection paths referenced toward PE:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>L1-PE + L2-PE + L3-PE + N-PE<\/strong><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">3+1 is widely used in TT systems and can also be used in suitable TN-S applications. 4+0 is commonly available for TN-S systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">However, the earthing system alone is not the complete specification.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Before selecting an SPD, verify the actual wiring diagram, protection modes, Uc, Up, In, Imax or Iimp, short-circuit conditions, backup protection and manufacturer installation requirements.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The most useful rule is simple:<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><strong>Do not choose an SPD by counting modules. Choose it by checking the network, protection paths and electrical ratings.<\/strong><\/p>\n<\/blockquote>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h1 class=\"wp-block-heading\">Sources Reviewed<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Technical references used to verify the concepts in this guide include:<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>IEC\/EN 61643-11<\/strong> \u2014 Low-voltage surge protective devices for AC power systems.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>IEC 60364-5-53<\/strong> \u2014 Selection and erection of electrical equipment, including SPD connection and application principles.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u30c7\u30fc\u30f3<\/strong> \u2014 Technical documentation for 3+1 TT\/TN-S and 4+0 TN-S surge arrester configurations.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u30eb\u30b0\u30e9\u30f3<\/strong> \u2014 Technical documentation identifying 3P+N \/ 3+1 L-N and N-PE protection modes.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>\u30af\u30a2\u30f3\u30cb\u30e3<\/strong> \u2014 VSP1S40 Type 2 AC SPD technical data and internal connection configurations.<\/p>","protected":false},"excerpt":{"rendered":"<p>A 3+1 vs 4+0 SPD comparison often starts with appearance, because both configurations may look almost identical from the outside, especially when they occupy four DIN-rail modules. But electrically, they are not the same. The main difference is the surge protection path. A typical 3+1 surge protective device uses three protection paths from the phase conductors to neutral: L1 \u2192 NL2 \u2192 NL3 \u2192 N plus one additional protection path: N \u2192 PE A typical 4+0 configuration instead provides protection paths referenced directly to PE, commonly: L1 \u2192 PEL2 \u2192 PEL3 \u2192 PEN \u2192 PE This difference affects how surge voltage is controlled between line, neutral and protective earth, so [&hellip;]<\/p>\n","protected":false},"author":7,"featured_media":4534,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[],"class_list":["post-4533","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/posts\/4533","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/comments?post=4533"}],"version-history":[{"count":1,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/posts\/4533\/revisions"}],"predecessor-version":[{"id":4544,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/posts\/4533\/revisions\/4544"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/media\/4534"}],"wp:attachment":[{"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/media?parent=4533"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/categories?post=4533"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/tags?post=4533"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}