A homeowner can do a surprising amount of useful work before the electrician arrives — and a lot of unhelpful work after. The trick is knowing where the line sits.
On the owner's side of the line
- Identifying which device tripped (MCB, RCBO, RCCB)
- Isolating a known-bad appliance and re-energising the rest of the circuit
- Cycling the main isolator after a brief power dip to clear an undervoltage trip
- Replacing a known-rated fuse in a plug top with the same rating
- Replacing a like-for-like light bulb or LED tube
- Pressing the RCD test button and confirming the device drops out
On the contractor's side of the line
- Anything that requires opening an accessory (face plate, junction box, DB cover)
- Insulation resistance, polarity or earth continuity testing
- Replacing an MCB, RCBO or RCCB
- Adding, extending or rerouting any circuit
- Working on water heater, AC or any dedicated-circuit appliance beyond filter cleaning
- Any electrical work in a wet zone
Cost of crossing the line the wrong way
Beyond personal safety, unauthorised electrical work in Singapore can affect insurance, complicate HDB resale, and create liability if a fault later causes damage. Under the Electricity Act, modifications and extensions to an installation must be carried out or supervised by an LEW — listed on the EMA ELISE Licensed Electrical Worker directory.
A diagnosis call-out is cheap
A 90-minute diagnosis visit is the cheapest call in the contractor's book. Use it. Trying to work out the fault from the wrong side of an unopened accessory wastes time and risks the fault getting worse.
What to have ready before the contractor arrives
- Which device tripped and when, ideally with timestamps for a recurring fault
- List of appliances on the affected circuit
- Last electrical work done in the unit (rough date, contractor, scope)
- Photo of the DB door labelling, if any
- Photo of any visible heat marks or damaged accessory