The MCB (miniature circuit breaker) in your switchboard has one job: cut the power before a fault becomes a fire. When it trips repeatedly, it isn't being moody — it's reporting a problem. Here's how to decode it.
First, notice the pattern
Trips when a specific appliance starts — the geyser, AC, or microwave. That circuit is overloaded or that appliance is faulty. This is the most common pattern in Indian homes, especially in winter when heaters and geysers stack onto old wiring.
Trips at random times — points to a loose connection heating up somewhere, or an intermittent short in wiring. Loose neutral connections are a classic and genuinely dangerous cause.
Trips instantly every time you reset it — a dead short circuit is live on that line. Stop resetting it. Repeated forcing of an MCB into a short is how insulation fires start.
The RCCB trips (the wider switch) — that's a current leak to earth, often a damp wall, a failing geyser element, or an appliance with worn insulation. RCCB trips deserve same-day attention.
What you can safely check yourself
- Unplug everything on the tripping circuit, reset, then reconnect devices one at a time — the one that trips it is your suspect
- Feel switchboard faceplates: warmth is a warning sign of loose terminals
- Look for blackening around sockets, or a fishy/burning smell — melting insulation smells like burnt fish
- Count what's running: a 16A circuit handles ~3,500W. A geyser (2,000W) plus a room heater (2,000W) on one circuit is already over