Kuangya • Low-Voltage AC Protection (50/60 Hz)

AC Circuit Breakers — MCB, RCCB, RCBO & AFDD

Overview of four protection layers for AC distribution: overcurrent (MCB), residual current (RCCB), the combined RCBOe arc-fault detection (AFDD). Use the cards below to jump to the right category page.

See Categories Comparação rápida

Overcurrent • AC

MCB — Miniature Circuit Breaker

Protects against overloads and short circuits (thermal-magnetic). Choose poles, rated current, and trip curve (B/C/D).

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Residual Current • AC

RCCB — Residual Current Circuit Breaker

Leakage protection only (no overcurrent). Requires upstream MCB/MCCB. Select type (AC/A/F/B/B+), sensitivity (IΔn), and poles.

Selection Guide →

Residual + Overcurrent • AC

RCBO — Combined Protection

Integrates MCB + RCD in one device. Ideal for terminal circuits that need both fault-current and overload/short-circuit protection.

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Arc Fault • AC

AFDD — Arc Fault Detection Device

Detects series/parallel arcing patterns to reduce fire risk. Often coordinated with RCBO/MCB in bedrooms and other sensitive areas.

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Quick Comparison (AC 50/60 Hz)

Core functions, pole options, and typical use. Detailed specs live on the category pages.

Tipo	Protects Against	Typical Poles	Common Settings	Typical Use (AC)
MCB	Overload & short-circuit (thermal-magnetic)	1P / 2P / 3P / 4P	In (e.g., 6–125A), Trip curve B/C/D	Feeders & branch circuits; coordinate with RCCB/RCBO/AFDD
RCCB	Residual (earth) current only	2P / 4P	IΔn 10/30/100/300 mA; Type AC/A/F/B/B+; S (selective)	Personnel protection; needs upstream MCB/MCCB
RCBO	Residual + overcurrent (combined)	1P+N / 2P / 3P+N / 4P	In, IΔn 10/30/100/300 mA; Type AC/A/F/B	Terminal circuits needing both protections in one
AFDD	Arc-fault (series/parallel) pattern detection	1P+N / 2P (by series)	Coordination with RCBO/MCB; installation guidelines	Bedrooms, aging wiring, combustible storage, IT rooms

Choose by AC Application

Jump to the most relevant category selector.

Residential / terminal circuits → RCBO Industrial personnel protection → RCCB Feeders & branch circuits → MCB High fire-risk areas → AFDD EV/VFD/DC leakage → RCBO Type B/F Selective coordination → RCCB S

Protection Stack & Coordination (AC)

Layer fault and surge protection for robust AC systems.

AC SPD MCB RCCB RCBO AFDD ATS

Resources

Trip Curves B/C/D — how to chooseMCB FAQ AC / A / F / B / B+ waveform typesRCCB Types Pole options & sensitivitiesRCBO Selector AFDD coordination with RCBO/MCBAFDD Guide

FAQs

What’s the difference between MCB, RCCB, RCBO and AFDD?

MCB handles overcurrent; RCCB handles residual current only; RCBO combines both; AFDD detects arc faults. Use the category pages to select models.

For AC terminal circuits, should I use RCCB or RCBO?

RCBO is often preferred because it integrates overcurrent and residual-current protection. RCCB requires an upstream MCB/MCCB.

When is AFDD recommended?

Where arc faults pose higher fire risks—e.g., bedrooms, aging wiring, combustible storage, or sensitive IT rooms. Coordinate with RCBO/MCB.