Four pole (FP) RCCB, 30 mA, 25A to 63A — cuts a three-phase + neutral supply on earth leakage to protect people from electric shock; 415 V AC.
- Trips on an earth leakage of 30 mA — the sensitivity used to protect people from electric shock.
- Four pole (three phases and neutral), for three-phase 415 V AC, 50 Hz supplies.
- Rated current 25A, 40A or 63A — pick from the options.
- Test button marked Test Monthly — press it once a month; the RCCB must trip.
- ISI-marked to IS/IEC 61008-1, as printed on the 40A and 63A units pictured.
- Does not trip on overload or short circuit — always install it with an MCB or fuse.
- 4 modules wide; snaps onto a standard 35 mm DIN rail.
An RCCB (residual current circuit breaker, often still called an ELCB) compares the current going out on the three phases and neutral with the current coming back, and switches the circuit off if part of it leaks to earth — through damaged insulation, a faulty appliance or a person.
At 30 mA it protects people: if someone touches a live part, or a faulty appliance leaks current through its metal body, it cuts the supply within a fraction of a second. The CEA safety regulations of 2023 require a residual current device of 30 mA or less in homes.
It does not trip on overload or short circuit, so it always works with MCBs or fuses. Ratings in this listing: 25A, 40A and 63A — choose one at or above the MCB that protects it.
Which RCCB do I need
- DP for single-phase supplies; FP for three-phase + neutral supplies.
- 30 mA: protects people — homes, bathrooms and socket circuits.
- 100 mA: equipment protection and upstream RCCBs.
- 300 mA: fire protection at the main incomer.
Where to use it
- Main RCCB of a three-phase home, shop or office.
- Three-phase + neutral sub-boards that feed sockets and appliances.
- Three-phase pump and borewell circuits.
- Schools, clinics, hostels and commercial kitchens.
How to install
- Switch off the main supply, confirm the board is dead, and snap the RCCB onto the DIN rail after the main MCB or isolator.
- Connect the supply to the LINE side and the outgoing circuits to the LOAD side, with the three phases and the neutral (N) on their marked terminals.
- Take every neutral of the protected circuits through the RCCB, and never join neutral and earth after it — either mistake makes it trip.
- Switch on, press the test button (the RCCB must trip), reset it and label the board.
Electrical work should be done by a licensed electrician. For AC circuits only.
Frequently asked questions
- Do I need an RCCB if I already have MCBs?
- Yes. MCBs trip on overload and short circuit; an RCCB trips on earth leakage — current escaping to earth through a fault or a person. A safe board needs both.
- Why 30 mA?
- 30 mA is the sensitivity used to protect people against electric shock, and the CEA safety regulations of 2023 require a residual current device of 30 mA or less in homes. 100 mA and 300 mA RCCBs protect equipment and guard against fire, not people.
- Which current rating do I need?
- One at or above the MCB or fuse that protects the RCCB. Typically 25A for a three-phase circuit or a small three-phase board, 40A for three-phase homes and shops and 63A for larger three-phase homes, shops and offices.
- Why does my RCCB keep tripping?
- Usually a real leak: a faulty geyser element, washing machine or pump, damp wiring, or a neutral touching earth or shared with a circuit outside the RCCB. Switch off all MCBs, reset the RCCB, then switch the MCBs on one by one to find the faulty circuit.
- How do I test an RCCB?
- Press the test button once a month with the power on. It should trip at once; switch it back on. If it does not trip, have it checked by an electrician.
Buy four pole 30 mA RCCBs online from Electric Market, Chennai. For site, contractor or bulk quantities, contact us for a quote.