Signs you need single to 3-phase upgrade
- Lights dim when two or three aircons start together
- The main switch trips on hot evenings with everything running
- You are adding an EV charger on top of several aircons
- Renovation plans include an induction hob, an oven and more water heaters
- You are installing a home lift, pool pump or 22kW charger
- Your contractor says the existing supply cannot take the new load
How much does single to 3-phase upgrade cost in KL?
Our current prices for single to 3-phase upgrade across Kuala Lumpur and Selangor (updated October 2026). You get a fixed quote on site before any work starts.
| Job | Price (RM) |
|---|---|
| Single to 3-phase upgrade (excl. TNB fees)per house | RM5,000 – RM8,000 |
| DB box replacement, 3-phaseper board · Board only | RM1,800 – RM3,500 |
| Surge protection device (SPD)per board | RM400 – RM700 |
| Dedicated circuit (oven, hob, aircond)per circuit | RM300 – RM500 |
| Inspection visit (minimum charge)per visit | From RM80 |
Prices include labour and standard materials (cable, trunking, standard switches and sockets) unless the item says otherwise. See the full price list.
What's included
- 1Load assessment of your current and planned appliances
- 2TNB application coordinated and followed up for you
- 3New 3-phase DB box with RCCBs and MCBs
- 4Circuits balanced across the three phases
- 5Testing and switch-over on the day TNB connects
- 612-month workmanship warranty
Do I need 3-phase power at home?
Single-phase is plenty for a normal terrace, but it runs out with four or five aircons, two water heaters, an induction hob and a 7kW EV charger running in the evening. If the main switch trips on hot nights or lights dim when a compressor starts, you are close to the limit.
3-phase gives roughly three times the capacity and lets you run a 22kW EV charger, a home lift or 3-phase aircond units. Your existing appliances keep working; we spread them across the three phases.
How long does a 3-phase upgrade take with TNB?
Our part, the DB box and wiring changes, takes one to two days. The wait is TNB. Before connecting a 3-phase supply, TNB requires the installation to be tested and the test certificates submitted. Processing usually takes 2–6 weeks, then TNB sets a date to fit the new meter and we switch the circuits over the same day.
TNB charges its own connection fee and security deposit, paid directly to TNB and not part of our price. The amount depends on your property and the load you apply for, and we tell you what to expect before applying.