ComponentsProtection & Safety

RCCB / RCD / GFCI

Breaker

A device that quickly cuts power when it detects leakage current to ground, protecting against electric shock and fire hazards.

Schematic symbol

Switch (SPST)

How rccb / rcd / gfci appears in a circuit diagram.

Types & variants

Type A (AC only)Type A-S (AC and pulsating DC)Type B (AC and smooth DC)40mA sensitivity30mA sensitivity10mA sensitivityCombined RCBO (with overload protection)

Key specs

Trip current

mA

Current level at which the device trips (typically 10mA, 30mA, or 40mA).

Breaking capacity

kA

Maximum fault current the device can safely interrupt without damage.

Response time

ms

Time to trip when leakage current exceeds threshold (typically <30ms).

Voltage rating

V

Maximum system voltage the device is designed to protect.

Markings

Rating labels show current (e.g., 30mA), voltage (e.g., 230V), and trip sensitivity (often a small 'IΔn' symbol). Test button functionality should be verified periodically.

Standard values

Common trip currents: 10mA (medical), 30mA (general), 40mA (industrial). Standard voltages: 230V, 400V. Breaking capacities: 4.5kA, 6kA, 10kA.

How to choose

1) Select trip current based on application (30mA for general use). 2) Ensure voltage rating matches your supply. 3) Check breaking capacity for your circuit's fault level. 4) Choose Type A for most residential/commercial use, Type B for specialized DC applications.

Pinout & package

Designed for DIN rail or surface mounting. Line (L) and Neutral (N) terminals clearly marked. Load terminals for output connections. No polarity on power terminals but must be correctly wired.

Example circuits

  • Main distribution board protection
  • Socket outlet in wet areas (bathrooms, kitchens)
  • Power tool protection
  • Medical equipment safety circuit
  • Swimming pool electrical safety

Common failures

Failure to trip when needed (mechanical wear or contamination), nuisance tripping (moisture or dust), internal circuit damage. Test button should be used monthly to verify functionality.

How to test

1) Use the built-in test button (monthly check). 2) For proper testing, use a dedicated RCD tester to verify trip time at rated current. 3) Never bypass or disable a faulty device - replace immediately.

Substitutes

No direct substitutes exist for safety-critical applications. For temporary testing, a portable GFCI/RCD tester can verify circuit protection.

Where to buy

DigiKeyMouserLCSCRobuAmazon