Why Does My MCB Keep Tripping? Causes and Fixes for Dhaka Flats
By Eng. Md Shakhawat, Lead Electrical Engineer · 2026-10-25
Short answer: an MCB trips to protect your wiring. The usual causes are overload (too many heavy appliances on one line), a short circuit, an earth fault (often from damp walls), or a weak or wrongly rated breaker. Replacing the breaker without finding the cause rarely fixes it.
The four common causes
| Cause | Typical sign | What it usually means |
|---|---|---|
| Overload | Trips when AC, geyser, iron or microwave run together | That line carries more current than it was designed for |
| Short circuit | Trips instantly, sometimes with a spark or burning smell | Live and neutral wires touching — a damaged cable, socket or appliance |
| Earth fault | RCCB trips, often in monsoon | Current leaking to earth — damp walls, wet sockets, faulty appliance |
| Faulty breaker | Trips at low load, feels hot | Old or poor-quality breaker, or a loose terminal |
What you can safely check
- Unplug everything on that line, reset the breaker, then plug appliances back one by one. If one appliance trips it every time, that appliance is the problem.
- Note when it trips. Only when the AC starts? Only when it rains? That tells the electrician a lot.
- Feel the DB box cover (don’t open it). If it’s hot, switch off the main and call for help — loose terminals are a fire risk.
Never tape a breaker in the ON position or replace it with a bigger rating “so it stops tripping”. The breaker is matched to the cable; a bigger breaker lets the cable overheat.
When to call an electrician
- It trips with a spark, smell or burnt mark
- The DB box or a socket feels hot
- It trips during rain (possible seepage into wiring)
- You’ve added an AC or geyser recently
We test the line, check cable size against the breaker, find the fault and fix it. If seepage is the cause, our plumbing team can fix the leak in the same visit.
Related services
- Main Circuit Breaker (MCB) InstallationBook
- Short Circuit RepairBook
- Distribution Board (DB) ServicingBook
- Electrical Checkup & InspectionBook
From our other division
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