{"id":2317,"date":"2025-12-29T11:01:33","date_gmt":"2025-12-29T11:01:33","guid":{"rendered":"https:\/\/cnkuangya.com\/?p=2317"},"modified":"2026-04-24T15:51:49","modified_gmt":"2026-04-24T07:51:49","slug":"top-10-dc-protection-wiring-mistakes","status":"publish","type":"post","link":"https:\/\/cnkuangya.com\/ja\/blog\/top-10-dc-protection-wiring-mistakes\/","title":{"rendered":"\u81f4\u547d\u7684\u306a\u6545\u969c\u306b\u3064\u306a\u304c\u308b\u76f4\u6d41\u4fdd\u8b77\u914d\u7dda\u306e\u9593\u9055\u3044\u30c8\u30c3\u30d710\uff1a\u30a8\u30f3\u30b8\u30cb\u30a2\u306e\u305f\u3081\u306e\u30ac\u30a4\u30c9"},"content":{"rendered":"

\u30b5\u30fc\u30e2\u30b0\u30e9\u30d5\u30a3\u306e\u30ec\u30f3\u30ba\u3092\u901a\u3059\u3068\u3001\u30dc\u30c3\u30af\u30b9\u306f\u707d\u5bb3\u5730\u5e2f\u3067\u3057\u305f\u3002\u5c4b\u4e0a\u306e\u5468\u56f2\u6e29\u5ea6\u306f40\u00b0C\uff08104\u00b0F\uff09\u3060\u3063\u305f\u306e\u306b\u5bfe\u3057\u3001\u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u5185\u306e\u7aef\u5b50\u306f180\u00b0C\uff08350\u00b0F\uff09\u3068\u3044\u3046\u6050\u308d\u3057\u3044\u6e29\u5ea6\u3067\u5149\u3063\u3066\u3044\u305f\u306e\u3067\u3059\u3002\u4e8b\u5f8c\u5206\u6790\u306e\u7d50\u679c\u3001\u6839\u672c\u7684\u306a\u539f\u56e0\u306f\u7aef\u5b50\u30e9\u30b0\u306e\u7de0\u3081\u4ed8\u3051\u304c\u4e0d\u9069\u5207\u3060\u3063\u305f\u3053\u3068\u3067\u3057\u305f\u30022\u5e74\u306b\u308f\u305f\u308b\u6bce\u65e5\u306e\u71b1\u30b5\u30a4\u30af\u30eb\uff08\u592a\u967d\u71b1\u306b\u3088\u308b\u81a8\u5f35\u3068\u53ce\u7e2e\uff09\u306b\u3088\u308a\u3001\u63a5\u7d9a\u90e8\u304c\u5f90\u3005\u306b\u7de9\u3093\u3067\u3044\u305f\u306e\u3060\u3002\u3053\u306e\u305f\u3081\u3001\u5c0f\u578b\u306e\u767a\u71b1\u4f53\u306e\u3088\u3046\u306a\u50cd\u304d\u3092\u3059\u308b\u9ad8\u62b5\u6297\u30dd\u30a4\u30f3\u30c8\u304c\u751f\u3058\u3001\u30a2\u30bb\u30f3\u30d6\u30ea\u5168\u4f53\u304c\u58ca\u6ec5\u7684\u306a\u706b\u707d\u306b\u81f3\u308b\u5bf8\u524d\u307e\u3067\u3001\u3086\u3063\u304f\u308a\u3068\u90e8\u54c1\u3092\u52a0\u71b1\u3057\u3066\u3044\u3063\u305f\u3002.<\/p>\n\n\n\n

This scenario is my world. As a senior application engineer, I\u2019ve been called to investigate dozens of failures just like this one. The hard truth is that while solar technology is more reliable than ever, the unique physics of Direct Current (DC) are unforgiving. Unlike the alternating current (AC) that powers our buildings, DC doesn’t naturally extinguish its own arc, making it far more dangerous when mishandled.<\/p>\n\n\n\n

\u6717\u5831\u306f\u3001\u3053\u3046\u3057\u305f\u6545\u969c\u306f\u307b\u3068\u3093\u3069\u4e88\u9632\u53ef\u80fd\u3060\u3068\u3044\u3046\u3053\u3068\u3060\u3002\u305d\u308c\u3089\u306f\u30a8\u30ad\u30be\u30c1\u30c3\u30af\u306a\u73fe\u8c61\u306b\u8d77\u56e0\u3059\u308b\u306e\u3067\u306f\u306a\u304f\u3001\u8a2d\u8a08\u3084\u8a2d\u7f6e\u306e\u6bb5\u968e\u3067\u72af\u3057\u3066\u3057\u307e\u3046\u4e00\u63e1\u308a\u306e\u4e00\u822c\u7684\u3067\u57fa\u672c\u7684\u306a\u904e\u3061\u304b\u3089\u751f\u3058\u3066\u3044\u308b\u306e\u3060\u3002\u3053\u306e\u30ac\u30a4\u30c9\u306f\u3001\u79c1\u304c\u6bce\u5e74\u73fe\u5834\u3067\u76ee\u306b\u3059\u308b\u30df\u30b9\u306e\u30c8\u30c3\u30d710\u3092\u96c6\u3081\u305f\u3082\u306e\u3067\u3059\u3002\u3053\u308c\u3089\u306e\u30b3\u30f3\u30bb\u30d7\u30c8\u3092\u30de\u30b9\u30bf\u30fc\u3059\u308c\u3070\u3001\u30b7\u30b9\u30c6\u30e0\u306e\u5b89\u5168\u6027\u3068\u9577\u5bff\u547d\u3092\u78ba\u4fdd\u3067\u304d\u308b\u3060\u3051\u3067\u306a\u304f\u3001\u3053\u306e\u696d\u754c\u306b\u304a\u3051\u308b\u771f\u306e\u30d7\u30ed\u30d5\u30a7\u30c3\u30b7\u30e7\u30ca\u30eb\u3068\u3057\u3066\u6607\u683c\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002.<\/p>\n\n\n\n

\u9593\u9055\u3044#1\uff1aAC\u30c7\u30d0\u30a4\u30b9\u306e\u4f7f\u7528 \u76f4\u6d41\u56de\u8def<\/a><\/h3>\n\n\n\n

\u3053\u308c\u306f\u9593\u9055\u3044\u306a\u304f\u3001\u65b0\u898f\u8a2d\u7f6e\u8005\u304c\u72af\u3057\u3046\u308b\u6700\u3082\u4e00\u822c\u7684\u3067\u5371\u967a\u306a\u9593\u9055\u3044\u3067\u3042\u308b\u3002\u6a19\u6e96\u7684\u306aAC\u5b9a\u683c\u306e\u30b5\u30fc\u30ad\u30c3\u30c8\u30d6\u30ec\u30fc\u30ab\u30fc\u3092\u30c8\u30e9\u30c3\u30af\u304b\u3089\u53d6\u3063\u3066\u304d\u3066DC\u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u30dc\u30c3\u30af\u30b9\u306b\u8a2d\u7f6e\u3059\u308b\u306e\u306f\u3001\u5927\u60e8\u4e8b\u306e\u3082\u3068\u3060\u3002.<\/p>\n\n\n\n

\u9593\u9055\u3044\u3060\uff1a<\/strong> \u30d6\u30ec\u30fc\u30ab\u30fc\u306f\u30d6\u30ec\u30fc\u30ab\u30fc\u3067\u3042\u308b\u3068\u4eee\u5b9a\u3059\u308b\u3002\u30a4\u30f3\u30b9\u30c8\u30fc\u30e9\u306f\u3001AC\u5b9a\u683c\u306e\u30d2\u30e5\u30fc\u30ba\u3001\u30d6\u30ec\u30fc\u30ab\u30fc\u3001\u307e\u305f\u306f\u30b9\u30a4\u30c3\u30c1\u3092DC\u56de\u8def\u306b\u4f7f\u7528\u3057\u307e\u3059\u3002.<\/p>\n\n\n\n

Why It’s Dangerous:<\/strong> AC and DC are fundamentally different. AC current passes through zero 120 times per second (in a 60Hz system). This “zero-crossing” moment provides an opportunity for an overcurrent protection device to extinguish the electrical arc that forms when its contacts open. A DC current, by contrast, is a continuous, relentless flow. When a DC device opens under load, it must stretch and cool the arc entirely on its own, without a zero-crossing to help. An AC breaker used in a DC circuit will likely fail to clear a fault, allowing a sustained arc to form. This arc is essentially plasma, reaching thousands of degrees, which will melt the device, burn through the enclosure, and ignite a fire.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

\u89e3\u6c7a\u7b56<\/strong><\/p>\n\n\n\n

    \n
  1. \u5fc5\u305aDC\u5b9a\u683c\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\uff1a<\/strong>\u00a0\u76f4\u6d41\u7528\u306b\u660e\u793a\u7684\u306b\u30ea\u30b9\u30c8\u3055\u308c\u3066\u3044\u308b\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306e\u307f\u3092\u4f7f\u7528\u3057\u3066\u304f\u3060\u3055\u3044\uff08\u4f8b\uff1a\u76f4\u6d41\u7528\u30e2\u30fc\u30eb\u30c9\u30b1\u30fc\u30b9\u30fb\u30b5\u30fc\u30ad\u30c3\u30c8\u30fb\u30d6\u30ec\u30fc\u30ab\u306eUL489B\u3001\u307e\u305f\u306fgPV\u5b9a\u683c\u30d2\u30e5\u30fc\u30ba\uff09\u3002.<\/li>\n\n\n\n
  2. \u96fb\u5727\u3068\u96fb\u6d41\u306e\u8868\u793a\u3092\u78ba\u8a8d\u3059\u308b<\/strong>: A properly rated DC device will have clear DC voltage (VDC) and amperage markings. If it only says “VAC,” it does not belong in your PV system.<\/li>\n\n\n\n
  3. \u30de\u30fc\u30ad\u30f3\u30b0\u3092\u7406\u89e3\u3059\u308b\uff1a<\/strong>\u00a0\u592a\u967d\u96fb\u6c60\u5c02\u7528\u30a2\u30d7\u30ea\u30b1\u30fc\u30b7\u30e7\u30f3\u7528\u306e\u7279\u5fb4\u7684\u306agPV\u30d2\u30e5\u30fc\u30ba\u30af\u30e9\u30b9\u3001\u307e\u305f\u306fAC\u7528\u306e\u6ce2\u7dda\u8a18\u53f7\uff08~\uff09\u3068\u306f\u5bfe\u7167\u7684\u306b\u3001DC\u7528\u306e\u76f4\u7dda\u8a18\u53f7\uff08-\uff09\u3092\u63a2\u3057\u307e\u3059\u3002.<\/li>\n<\/ol>\n\n\n\n
    \u7279\u5fb4<\/th>AC\u30b5\u30fc\u30ad\u30c3\u30c8\u30d6\u30ec\u30fc\u30ab\u30fc<\/th>DC\u30b5\u30fc\u30ad\u30c3\u30c8\u30d6\u30ec\u30fc\u30ab\u30fc<\/a><\/th><\/tr>
    \u30a2\u30fc\u30af\u713c\u5165\u308c<\/strong><\/td>AC\u30bc\u30ed\u30af\u30ed\u30b9\u306b\u4f9d\u5b58<\/td>\u30de\u30b0\u30cd\u30c3\u30c8\u3001\u5927\u578b\u30a2\u30fc\u30af\u30b7\u30e5\u30fc\u30c8\u3092\u4f7f\u7528<\/td><\/tr>
    \u6975\u6027<\/strong><\/td>\u7121\u6975\u6027<\/td>\u6975\u6027\u304c\u3042\u308b\u3053\u3068\u304c\u591a\u3044\uff08\u6b63\u3057\u304f\u914d\u7dda\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\uff09<\/td><\/tr>
    \u30ea\u30b9\u30c8<\/strong><\/td>UL489\u3001IEC 60947-2<\/td>UL489B\u3001IEC 60947-2\uff08DC\u5b9a\u683c\u4ed8\u304d\uff09<\/td><\/tr>
    \u5178\u578b\u7684\u306a\u4f7f\u7528\u4f8b<\/strong><\/td>\u5efa\u7269\u306e\u914d\u96fb\u76e4<\/td>\u592a\u967d\u5149\u767a\u96fb\u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u3001\u30d0\u30c3\u30c6\u30ea\u30fc\u30d0\u30f3\u30af<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    \u91cd\u8981\u306a\u53ce\u7a6b<\/strong> If it doesn’t say DC, don’t use it. Period.<\/p>\n\n\n\n

    \u8aa4\u308a#2\uff1a\u5b9a\u683c\u96fb\u5727\u306e\u8aa4\u308a<\/h3>\n\n\n\n

    \u96fb\u5727\u306f\u96fb\u6c17\u7684\u306a\u5727\u529b\u3067\u3059\u3002\u5727\u529b\u304c\u5bb9\u5668\u306e\u5b9a\u683c\u3092\u4e0a\u56de\u308c\u3070\u3001\u5bb9\u5668\u306f\u6545\u969c\u3059\u308b\u3002PV\u30b7\u30b9\u30c6\u30e0\u3067\u306f\u3001\u3053\u306e\u6545\u969c\u306f\u7206\u767a\u7684\u306a\u3082\u306e\u306b\u306a\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u3002.<\/p>\n\n\n\n

    \u9593\u9055\u3044\u3060\uff1a<\/strong> \u30b7\u30b9\u30c6\u30e0\u306e\u6700\u5927\u96fb\u5727\u3088\u308a\u3082\u4f4e\u3044\u5b9a\u683c\u96fb\u5727\u306e\u4fdd\u8b77\u88c5\u7f6e\u3092\u9078\u629e\u3059\u308b\u3002.<\/p>\n\n\n\n

    Why It’s Dangerous:<\/strong> \u30bd\u30fc\u30e9\u30fc\u30d1\u30cd\u30eb\u306e\u30b9\u30c8\u30ea\u30f3\u30b0\u306e\u96fb\u5727\u306f\u4e00\u5b9a\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002\u958b\u56de\u8def\u6642\uff08Voc\uff09\u306b\u6700\u3082\u9ad8\u304f\u306a\u308a\u3001\u5bd2\u51b7\u6642\u306b\u306f\u4e0a\u6607\u3057\u307e\u3059\u3002NEC\u7b2c690.7\u6761\u306f\u3001\u8a2d\u7f6e\u8005\u306b\u3001\u305d\u306e\u5834\u6240\u3067\u4e88\u60f3\u3055\u308c\u308b\u6700\u4f4e\u306e\u5468\u56f2\u6e29\u5ea6\u306b\u57fa\u3065\u3044\u3066\u3001\u30b7\u30b9\u30c6\u30e0\u306e\u6700\u5927\u96fb\u5727\u3092\u8a08\u7b97\u3059\u308b\u3088\u3046\u6c42\u3081\u3066\u3044\u308b\u3002\u5bd2\u3044\u51ac\u306e\u671d\u306b650VDC\u306b\u9054\u3059\u308b\u53ef\u80fd\u6027\u306e\u3042\u308b\u30b7\u30b9\u30c6\u30e0\u306b600VDC\u5b9a\u683c\u306e\u30d6\u30ec\u30fc\u30ab\u3092\u8a2d\u7f6e\u3059\u308b\u3053\u3068\u306f\u3001\u81f4\u547d\u7684\u306a\u6545\u969c\u3092\u62db\u304f\u3053\u3068\u306b\u306a\u308a\u307e\u3059\u3002\u904e\u96fb\u5727\u72b6\u614b\u306f\u3001\u30c7\u30d0\u30a4\u30b9\u304c\u6545\u969c\u3092\u906e\u65ad\u3067\u304d\u305a\u306b\u30a2\u30fc\u30af\u653e\u96fb\u3092\u5f15\u304d\u8d77\u3053\u3057\u305f\u308a\u3001\u30c7\u30d0\u30a4\u30b9\u5185\u90e8\u306e\u7d76\u7e01\u304c\u58ca\u6ec5\u7684\u306b\u7834\u58ca\u3055\u308c\u308b\u7d76\u7e01\u7834\u58ca\u3092\u5f15\u304d\u8d77\u3053\u3057\u305f\u308a\u3059\u308b\u53ef\u80fd\u6027\u304c\u3042\u308a\u307e\u3059\u3002.<\/p>\n\n\n\n

    \u89e3\u6c7a\u7b56<\/strong><\/p>\n\n\n\n

      \n
    1. \u6700\u5927\u30b7\u30b9\u30c6\u30e0\u96fb\u5727\u306e\u8a08\u7b97\uff1a<\/strong>\u00a0Use the temperature correction factors from NEC Table 690.7(A) to find the corrected Voc for your location’s record low temperature. For example, a string with a Voc of 580V at 25\u00b0C could easily exceed 650V at -10\u00b0C.<\/li>\n\n\n\n
    2. \u5f93\u3063\u3066\u30c7\u30d0\u30a4\u30b9\u3092\u9078\u629e\u3059\u308b\uff1a<\/strong>\u00a0\u30d2\u30e5\u30fc\u30ba\u3001\u30d6\u30ec\u30fc\u30ab\u3001\u65ad\u8def\u5668\u306e\u5b9a\u683c\u76f4\u6d41\u96fb\u5727\u306f\u3001\u3053\u306e\u8a08\u7b97\u3055\u308c\u305f\u6700\u5927\u96fb\u5727\u3068\u540c\u7b49\u307e\u305f\u306f\u305d\u308c\u4ee5\u4e0a\u306e\u3082\u306e\u3092\u9078\u629e\u3057\u3066\u304f\u3060\u3055\u3044\u3002.<\/li>\n\n\n\n
    3. \u30b7\u30b9\u30c6\u30e0\u5168\u4f53\u3092\u8003\u3048\u308b\uff1a<\/strong>\u00a0\u3053\u308c\u306f\u3001\u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u3001\u30ea\u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u3001\u30a4\u30f3\u30d0\u30fc\u30bf\u30fc\u3001\u305d\u3057\u3066\u30a2\u30ec\u30a4\u304b\u3089\u30a4\u30f3\u30d0\u30fc\u30bf\u30fc\u307e\u3067\u306e\u30c7\u30a3\u30b9\u30b3\u30cd\u30af\u30c8\u306a\u3069\u3001\u3059\u3079\u3066\u306e\u30b3\u30f3\u30dd\u30fc\u30cd\u30f3\u30c8\u306b\u9069\u7528\u3055\u308c\u308b\u3002.<\/li>\n<\/ol>\n\n\n\n

      \u30d7\u30ed\u306e\u30a2\u30c9\u30d0\u30a4\u30b9<\/strong> Always add a safety margin. If your calculated max voltage is 590V, don’t use a 600V device. Step up to the next standard rating (e.g., 800V or 1000V) for enhanced safety and reliability.<\/p>\n\n\n\n

      \u9593\u9055\u3044#3\uff1a\u6975\u6027\u30d6\u30ec\u30fc\u30ab\u30fc\u306e\u6975\u6027\u53cd\u8ee2<\/h3>\n\n\n\n

      In the world of DC, direction matters. Many DC circuit breakers are “polarized,” meaning they are designed to have current flow through them in only one direction.<\/p>\n\n\n\n

      \u9593\u9055\u3044\u3060\uff1a<\/strong> \u6975\u6027DC\u30d6\u30ec\u30fc\u30ab\u30fc\u3092\u9006\u306b\u914d\u7dda\u3057\u3001\u30bd\u30fc\u30b9\u3092\u8ca0\u8377\u7aef\u5b50\u306b\u63a5\u7d9a\u3059\u308b\u3002.<\/p>\n\n\n\n

      Why It’s Dangerous:<\/strong> \u6975\u6027\u30d6\u30ec\u30fc\u30ab\u30fc\u306b\u306f\u3001\u5c0f\u3055\u306a\u6c38\u4e45\u78c1\u77f3\u304c\u5165\u3063\u3066\u3044\u307e\u3059\u3002\u3053\u308c\u3089\u306e\u78c1\u77f3\u306f\u3001\u30d6\u30ec\u30fc\u30ab\u30fc\u3092\u62bc\u3057\u51fa\u3059\u305f\u3081\u306b\u6226\u7565\u7684\u306b\u914d\u7f6e\u3055\u308c\u3066\u3044\u307e\u3059\u3002 \u305d\u306e <\/strong>electrical arc into the “arc chute” when the contacts open. The arc chute is a chamber of metal fins designed to stretch, cool, and extinguish the arc. If you wire the breaker backward, the magnets will push the arc in the \u53cd\u5bfe\u65b9\u5411<\/em>-\u30a2\u30fc\u30af\u30b7\u30e5\u30fc\u30c8\u304b\u3089\u96e2\u308c\u3001\u30d6\u30ec\u30fc\u30ab\u672c\u4f53\u306e\u53ef\u71c3\u6027\u30d7\u30e9\u30b9\u30c1\u30c3\u30af\u30dc\u30c7\u30a3\u306b\u76f4\u63a5\u5dee\u3057\u8fbc\u307f\u307e\u3059\u3002\u3053\u306e\u5834\u5408\u3001\u30d6\u30ec\u30fc\u30ab\u306f\u5373\u5ea7\u306b\u7834\u58ca\u3055\u308c\u3001\u7b50\u4f53\u5185\u90e8\u3067\u306f\u307b\u307c\u78ba\u5b9f\u306b\u706b\u707d\u304c\u767a\u751f\u3057\u307e\u3059\u3002.<\/p>\n\n\n\n

      \u89e3\u6c7a\u7b56<\/strong><\/p>\n\n\n\n

        \n
      1. \u7aef\u5b50\u3092\u7279\u5b9a\u3059\u308b\uff1a<\/strong>\u00a0Look for the “+” and “-” markings, or “LINE” and “LOAD” labels on the breaker. In solar applications, the “LINE” side should always be connected to the source (the PV strings) and the “LOAD” side to the destination (the busbar or inverter).<\/li>\n\n\n\n
      2. \u63a5\u7d9a\u3092\u30c0\u30d6\u30eb\u30c1\u30a7\u30c3\u30af\u3059\u308b<\/strong>\u00a0\u30b7\u30b9\u30c6\u30e0\u306b\u901a\u96fb\u3059\u308b\u524d\u306b\u3001\u914d\u7dda\u3092\u7269\u7406\u7684\u306b\u30c8\u30ec\u30fc\u30b9\u3057\u3001\u6975\u6027\u30c7\u30d0\u30a4\u30b9\u304c\u3059\u3079\u3066\u6b63\u3057\u304f\u63a5\u7d9a\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3057\u3066\u304f\u3060\u3055\u3044\u3002.<\/li>\n\n\n\n
      3. \u30c1\u30fc\u30e0\u3092\u935b\u3048\u308b\uff1a<\/strong>\u00a0\u3053\u308c\u306f\u3001\u3059\u3079\u3066\u306e\u8a2d\u7f6e\u8005\u306b\u3068\u3063\u3066\u91cd\u8981\u306a\u30c8\u30ec\u30fc\u30cb\u30f3\u30b0\u30dd\u30a4\u30f3\u30c8\u3067\u3059\u3002\u73fe\u5834\u306e\u5168\u54e1\u304c\u3001\u6975\u6027\u30c7\u30d0\u30a4\u30b9\u306e\u6a5f\u80fd\u3068\u3001\u305d\u308c\u3092\u9006\u306b\u914d\u7dda\u3057\u305f\u5834\u5408\u306e\u6df1\u523b\u306a\u7d50\u679c\u3092\u7406\u89e3\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002.<\/li>\n<\/ol>\n\n\n\n

        \u91cd\u8981\u306a\u53ce\u7a6b<\/strong> \u6975\u6027DC\u30d6\u30ec\u30fc\u30ab\u3067\u306f\u3001LINE\u3068LOAD\u306f\u63d0\u6848\u3067\u306f\u306a\u304f\u3001\u91cd\u8981\u306a\u5b89\u5168\u8981\u4ef6\u3067\u3042\u308b\u3002.<\/p>\n\n\n\n

        \"RCCB<\/figure>\n\n\n\n

        \u9593\u9055\u3044#4\uff1a\u4e0d\u9069\u5207\u306a\u904e\u96fb\u6d41\u30b5\u30a4\u30b8\u30f3\u30b0<\/h3>\n\n\n\n

        \u904e\u96fb\u6d41\u4fdd\u8b77\u88c5\u7f6e\uff08OCPD\uff09\u306e\u30b5\u30a4\u30ba\u6c7a\u5b9a \u306b\u3068\u3063\u3066 <\/strong>\u30bd\u30fc\u30e9\u30fc\u56de\u8def\u306e\u30b5\u30a4\u30b8\u30f3\u30b0\u306f\u3001\u6a19\u6e96\u7684\u306aAC\u8ca0\u8377\u306e\u30b5\u30a4\u30b8\u30f3\u30b0\u3068\u306f\u7570\u306a\u308a\u307e\u3059\u3002\u9593\u9055\u3063\u305f\u8a08\u7b97\u3092\u3059\u308b\u3068\u3001\u8ff7\u60d1\u306a\u30c8\u30ea\u30c3\u30d7\u304c\u767a\u751f\u3057\u305f\u308a\u3001\u6700\u60aa\u306e\u5834\u5408\u3001\u56de\u8def\u3092\u5b8c\u5168\u306b\u4fdd\u8b77\u3067\u304d\u306a\u304f\u306a\u3063\u305f\u308a\u3057\u307e\u3059\u3002.<\/p>\n\n\n\n

        \u9593\u9055\u3044\u3060\uff1a<\/strong> \u30d2\u30e5\u30fc\u30ba\u307e\u305f\u306f\u30d6\u30ec\u30fc\u30ab\u30fc\u306e\u30b5\u30a4\u30b8\u30f3\u30b0 \u306e\u307f <\/strong>on the panel’s nameplate current (Isc) or using standard AC sizing rules.<\/p>\n\n\n\n

        Why It’s Dangerous:<\/strong> \u30bd\u30fc\u30e9\u30fc\u30b5\u30fc\u30ad\u30c3\u30c8\u3092\u8003\u3048\u308b a<\/strong> \u9023\u7d9a\u8ca0\u8377\u3068 <\/strong>\u5bfe\u8c61 \u3078\u306e<\/strong> “edge of cloud” effects, <\/strong>\u901a\u904e\u3059\u308b\u96f2\u304c\u653e\u5c04\u7167\u5ea6\u3092\u4e00\u6642\u7684\u306b\u5897\u52a0\u3055\u305b\u3001\u96fb\u6d41\u51fa\u529b\u3092\u5897\u52a0\u3055\u305b\u308b\u3053\u3068\u304c\u3042\u308b\u3002NEC \u7b2c690.9\u6761(A)\u3067\u306f\u3001\u4e21\u65b9\u306e\u8981\u56e0\u3092\u8003\u616e\u3057\u305f\u7279\u5b9a\u306e\u30b5\u30a4\u30ba\u6c7a\u5b9a\u5f0f\u3092\u7fa9\u52d9\u4ed8\u3051\u3066\u3044\u307e\u3059\u3002\u30d2\u30e5\u30fc\u30ba\u306e\u30b5\u30a4\u30ba\u3092\u5c0f\u3055\u304f\u3057\u904e\u304e\u308b\u3068\u3001\u901a\u5e38\u306e\u30d4\u30fc\u30af\u6761\u4ef6\u3067\u30d2\u30e5\u30fc\u30ba\u304c\u6eb6\u65ad\u3057\u3066\u3057\u307e\u3044\u307e\u3059\uff08\u8ff7\u60d1\u30c8\u30ea\u30c3\u30d7\uff09\u3002\u30d2\u30e5\u30fc\u30ba\u306e\u30b5\u30a4\u30ba\u3092\u5927\u304d\u304f\u3057\u904e\u304e\u308b\u3068\u3001\u6545\u969c\u6642\u306e\u904e\u71b1\u304b\u3089\u5c0e\u4f53\u3092\u4fdd\u8b77\u3067\u304d\u305a\u3001\u706b\u707d\u306e\u5371\u967a\u304c\u751f\u3058\u307e\u3059\u3002.<\/p>\n\n\n\n

        \u89e3\u6c7a\u7b56<\/strong> NEC\u306f\u30012\u3064\u306e\u30d1\u30fc\u30c8\u304b\u3089\u306a\u308b\u8a08\u7b97\u30921\u3064\u306e\u500d\u7387\u306b\u307e\u3068\u3081\u308b\u3053\u3068\u3092\u898f\u5b9a\u3057\u3066\u3044\u308b\uff1a 1.56<\/strong>.<\/p>\n\n\n\n

          \n
        1. \u5fc5\u8981\u306a\u683c\u4ed8\u3051\u3092\u8a08\u7b97\u3059\u308b\uff1a<\/strong>\u00a0The minimum OCPD rating is the string’s short-circuit current (Isc) multiplied by 1.56.\n
            \n
          • \u5fc5\u8981\u5b9a\u683c\uff1dIsc\u00d71.25\uff08\u9023\u7d9a\u8ca0\u8377\u6642\uff09\u00d71.25\uff08\u904e\u7167\u5c04\u6642\uff09\uff1dIsc\u00d71.56<\/code><\/li>\n<\/ul>\n<\/li>\n\n\n\n
          • \u6b21\u306e\u6a19\u6e96\u30b5\u30a4\u30ba\u3092\u9078\u629e\u3057\u307e\u3059\uff1a<\/strong>\u00a0\u5fc5\u8981\u306a\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u3092\u8a08\u7b97\u3057\u305f\u5f8c\u3001\u4ee5\u4e0b\u306e\u9805\u76ee\u3092\u9078\u629e\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u00a0\u6b21\u306e\u6a19\u6e96\u30b5\u30a4\u30ba<\/em>\u3092\u30d2\u30e5\u30fc\u30ba\u307e\u305f\u306f\u30d6\u30ec\u30fc\u30ab\u30fc\u306b\u5272\u308a\u5f53\u3066\u308b\u3002\u4f8b\u3048\u3070\u3001Isc\u304c9.8A\u306e\u30b9\u30c8\u30ea\u30f3\u30b0\u304c\u3042\u308b\u3068\u3057\u307e\u3059\uff1a\n
              \n
            • \u5fc5\u8981\u5b9a\u683c = 9.8A \u00d7 1.56 = 15.29A<\/code><\/li>\n\n\n\n
            • \u6b21\u306b\u6a19\u6e96\u7684\u306a\u30d2\u30e5\u30fc\u30ba\u306e\u30b5\u30a4\u30ba\u306f20A\u3067\u3059\u300215A\u306e\u30d2\u30e5\u30fc\u30ba\u3067\u306f\u5c0f\u3055\u3059\u304e\u3066\u8ff7\u60d1\u306a\u30c8\u30ea\u30c3\u30d7\u306b\u3064\u306a\u304c\u308b\u3002.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
              \u30b5\u30a4\u30ba\u4f8b<\/th>\u4e0d\u9069\u5207\u306a\u30b5\u30a4\u30b8\u30f3\u30b0\uff08Isc\u306e\u307f\uff09<\/th>\u9069\u5207\u306a\u30b5\u30a4\u30b8\u30f3\u30b0\uff08NEC 1.56\u500d\u30eb\u30fc\u30eb\uff09<\/th><\/tr>
              \u6587\u5b57\u5217 Isc<\/strong><\/td>9.8A<\/td>9.8A<\/td><\/tr>
              \u8a08\u7b97<\/strong><\/td>9.8A\u219210A\u30d2\u30e5\u30fc\u30ba\u306b\u6700\u3082\u8fd1\u3044\u30b5\u30a4\u30ba\u3092\u9078\u629e<\/td>9.8a * 1.56 = 15.29a<\/code><\/td><\/tr>
              \u9078\u629e\u3055\u308c\u305fOCPD<\/strong><\/td>10A\u30d2\u30e5\u30fc\u30ba<\/td>20A\u30d2\u30e5\u30fc\u30ba\uff081\u3064\u4e0a\u306e\u6a19\u6e96\u30b5\u30a4\u30ba\uff09<\/td><\/tr>
              \u7d50\u679c<\/strong><\/td>\u6674\u308c\u305f\u65e5\u306e\u8ff7\u60d1\u306a\u30c8\u30ea\u30c3\u30d7<\/td>\u5b89\u5168\u3067\u4fe1\u983c\u6027\u306e\u9ad8\u3044\u64cd\u4f5c<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

              \u30d7\u30ed\u306e\u30a2\u30c9\u30d0\u30a4\u30b9<\/strong> Always check the module’s datasheet for \u305d\u306e<\/strong> “Maximum Series Fuse Rating.” Your calculated OCPD size must not exceed this value. If it does, your string design is flawed.<\/p>\n\n\n\n

              \u9593\u9055\u3044#5\uff1a\u6e29\u5ea6\u30c7\u30a3\u30ec\u30fc\u30c6\u30a3\u30f3\u30b0\u306e\u7121\u8996<\/h3>\n\n\n\n

              \u30d6\u30ec\u30fc\u30ab\u30fc\u307e\u305f\u306f\u30d2\u30e5\u30fc\u30ba\u306b\u523b\u5370\u3055\u308c\u3066\u3044\u308b\u5b9a\u683c\u96fb\u6d41\u306f\u3001\u7279\u5b9a\u306e\u7ba1\u7406\u3055\u308c\u305f\u5468\u56f2\u6e29\u5ea6\uff08\u901a\u5e38\u3001\u30d6\u30ec\u30fc\u30ab\u30fc\u306f40\u2103\u3001\u30d2\u30e5\u30fc\u30ba\u306f25\u2103\uff09\u3067\u306e\u307f\u6709\u52b9\u3067\u3059\u3002\u30c6\u30ad\u30b5\u30b9\u306e\u9ed2\u3044\u5546\u696d\u7528\u5c4b\u6839\u306e\u4e0a\u306e\u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u30dc\u30c3\u30af\u30b9\u306f\u3001\u7ba1\u7406\u3055\u308c\u305f\u74b0\u5883\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002.<\/p>\n\n\n\n

              \u9593\u9055\u3044\u3060\uff1a<\/strong> \u7b50\u4f53\u5185\u306e\u5b9f\u969b\u306e\u5468\u56f2\u6e29\u5ea6\u306b\u5408\u308f\u305b\u3066\u4fdd\u8b77\u88c5\u7f6e\u306e\u901a\u96fb\u5bb9\u91cf\u3092\u8abf\u6574\u3057\u306a\u304b\u3063\u305f\u3053\u3068\u3002.<\/p>\n\n\n\n

              Why It’s Dangerous:<\/strong> Heat is the enemy of electrical components. A circuit breaker that is rated for 100A at 40\u00b0C might only be able to handle 85A continuously when the temperature inside the combiner box reaches 60\u00b0C (140\u00b0F). If you’re pushing 90A through it, the breaker’s internal thermal trip mechanism will activate, causing a nuisance trip. This leads to system downtime and expensive troubleshooting calls. For fuses, high ambient temperatures can degrade the fuse element over time, causing it to fail prematurely.<\/p>\n\n\n\n

              \u89e3\u6c7a\u7b56<\/strong><\/p>\n\n\n\n

                \n
              1. \u63a8\u5b9a\u30a8\u30f3\u30af\u30ed\u30fc\u30b8\u30e3\u6e29\u5ea6\uff1a<\/strong>\u00a0\u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u30dc\u30c3\u30af\u30b9\u306e\u73fe\u5b9f\u7684\u306a\u5185\u90e8\u6e29\u5ea6\u3092\u6c7a\u5b9a\u3059\u308b\u3002\u4e00\u822c\u7684\u306a\u7d4c\u9a13\u5247\u3067\u306f\u3001\u7279\u306b\u76f4\u5c04\u65e5\u5149\u306e\u5f53\u305f\u308b\u5834\u6240\u306b\u8a2d\u7f6e\u3059\u308b\u5834\u5408\u306f\u3001\u305d\u306e\u5834\u6240\u306e\u65e5\u4e2d\u306e\u6700\u9ad8\u5e73\u5747\u6c17\u6e29\u306b20\uff5e30\u2103\u3092\u52a0\u3048\u308b\u3002.<\/li>\n\n\n\n
              2. \u30e1\u30fc\u30ab\u30fc\u306e\u30c7\u30fc\u30bf\u30b7\u30fc\u30c8\u3092\u53c2\u7167\u3057\u3066\u304f\u3060\u3055\u3044\uff1a<\/strong>\u00a0Find the temperature derating chart in the device’s technical datasheet. This will provide correction factors for various temperatures.<\/li>\n\n\n\n
              3. \u88dc\u6b63\u4fc2\u6570\u3092\u9069\u7528\u3059\u308b\uff1a<\/strong>\u00a0\u8a08\u7b97\u5f0f\u306f\u3053\u3046\u3060\uff1a\u00a0\u6709\u52b9\u5b9a\u683c\uff1d\u516c\u79f0\u5b9a\u683c\u00d7\u88dc\u6b63\u4fc2\u6570<\/code>. .\u6b63\u3057\u3044\u30b5\u30a4\u30ba\u3092\u4f5c\u308b\u306b\u306f\u3001\u9006\u7b97\u3057\u306a\u3051\u308c\u3070\u306a\u3089\u306a\u3044\uff1a\u00a0\u5fc5\u8981\u306a\u516c\u79f0\u5b9a\u683c = \u56de\u8def\u30a2\u30f3\u30da\u30a2 \/ \u88dc\u6b63\u4fc2\u6570<\/code>.\n
                  \n
                • Example: You need to protect a 40A circuit inside a box that will reach 60\u00b0C. The breaker’s datasheet shows a correction factor of 0.85 at 60\u00b0C.<\/li>\n\n\n\n
                • \u5fc5\u8981\u306a\u516c\u79f0\u5b9a\u683c = 40A \/ 0.85 = 47A<\/code>. .\u305d\u306e\u9ad8\u6e29\u74b0\u5883\u306740A\u3092\u5b89\u5168\u306b\u51e6\u7406\u3059\u308b\u306b\u306f\u300150A\u306e\u30d6\u30ec\u30fc\u30ab\u30fc\u3092\u9078\u3076\u5fc5\u8981\u304c\u3042\u308b\u3002.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n\n\n\n
                  \u5468\u56f2\u6e29\u5ea6<\/th>\u88dc\u6b63\u4fc2\u6570<\/th>100A Breaker’s True Capacity<\/th><\/tr>
                  40\u00b0C<\/td>1.0<\/td>100A<\/td><\/tr>
                  50\u00b0C<\/td>0.92<\/td>92A<\/td><\/tr>
                  60\u00b0C<\/td>0.85<\/td>85A<\/td><\/tr>
                  70\u00b0C<\/td>0.77<\/td>77A<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

                  \u91cd\u8981\u306a\u53ce\u7a6b<\/strong> \u30b3\u30f3\u30d0\u30a4\u30ca\u30fc\u304c\u9ad8\u6e29\u306b\u306a\u308b\u3053\u3068\u3092\u60f3\u5b9a\u3057\u3001\u305d\u308c\u306b\u5fdc\u3058\u3066\u4fdd\u8b77\u88c5\u7f6e\u306e\u30b5\u30a4\u30ba\u3092\u6c7a\u3081\u308b\u3002\u9298\u677f\u5b9a\u683c\u306f\u51fa\u767a\u70b9\u3067\u3042\u308a\u3001\u6700\u7d42\u7684\u306a\u7b54\u3048\u3067\u306f\u3042\u308a\u307e\u305b\u3093\u3002.<\/p>\n\n\n\n

                  \"\"<\/figure>","protected":false},"excerpt":{"rendered":"

                  Through the lens of a thermal camera, the box was a disaster zone. While the ambient rooftop temperature was a blistering 104\u00b0F (40\u00b0C), the terminals inside the combiner were glowing at a terrifying 350\u00b0F (180\u00b0C). A post-mortem analysis showed the root cause: improperly torqued terminal lugs. Two years of daily thermal cycling\u2014the expansion and contraction from solar heating\u2014had progressively loosened the connections. This created high-resistance points that acted like miniature heating elements, slowly cooking the components until the entire assembly was on the verge of a catastrophic fire. This scenario is my world. As a senior application engineer, I\u2019ve been called to investigate dozens of failures just like this one. […]<\/p>\n","protected":false},"author":4,"featured_media":2318,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[45],"tags":[],"class_list":["post-2317","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-dc-protection-safety"],"blocksy_meta":[],"_links":{"self":[{"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/posts\/2317","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\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/comments?post=2317"}],"version-history":[{"count":1,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/posts\/2317\/revisions"}],"predecessor-version":[{"id":2320,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/posts\/2317\/revisions\/2320"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/media\/2318"}],"wp:attachment":[{"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/media?parent=2317"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/categories?post=2317"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cnkuangya.com\/ja\/wp-json\/wp\/v2\/tags?post=2317"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}