Factory Power Calculator: How Many Amps Do You Need?
Example rows, replace them with your own machines.
- Connected load
- 97 kW
- Estimated running current
- 132 A
Estimate only. The final supply size must be worked out by a registered electrical engineer and approved by TNB.
Built by Peter Tan (REN 12771)
Peter is an industrial property negotiator with a software engineering background. He built FactoryHub.my and its spec tools himself, so buyers and tenants can shortlist factories by power supply, ceiling height and floor loading before the first viewing.
About Peter →How the calculation works
- Connected load: the kW of every machine, multiplied by how many you have.
- Running load: the connected load multiplied by the share that runs at the same time.
- Current: amps = kW x 1,000 / (1.732 x 400 x power factor). At a power factor of 0.85, 1 kW is about 1.7 A.
- Supply to look for: the current plus your spare capacity, rounded up to the next common supply size seen on factory listings.
Reading the amperage on a factory listing
Factory listings in Malaysia state the incoming supply in amps, for example 300 A or 1,000 A three phase. A 300 A supply is about 208 kVA, enough for roughly 177 kW of load running together. The figure usually comes from the owner, so confirm it on the main switchboard, the TNB meter and a recent bill before you sign.
Factories by power and other specs
FAQ
How many amps does my factory need?
Add up the kW of all your machines, multiply by the share that runs at the same time, convert to amps and add room to grow. For example, 150 kW of machines with 80% running together at a power factor of 0.85 draws about 204 A on a 400 V three-phase supply. With 25% spare capacity that is about 255 A, so look for a factory with at least 300 A.
How do I convert kW to amps for a three-phase supply in Malaysia?
Amps = kW x 1,000 / (1.732 x 400 x power factor). TNB low-voltage supply is 400 V three phase, so at a power factor of 0.85 each kW draws about 1.7 A. 100 kW is therefore about 170 A.
What does a 300A three-phase factory supply mean?
A 300 A supply at 400 V three phase is about 208 kVA. At a power factor of 0.85 that runs roughly 177 kW of load at the same time. The amperage on a factory listing is the size of the incoming supply, not what the current tenant uses.
Is the amperage on a factory listing always accurate?
Not always. It usually comes from the owner or the original listing. Before you sign, check the main switchboard, the TNB meter and a recent TNB bill, and have your electrician confirm the incoming supply.
What if the factory does not have enough power?
The supply can often be upgraded through a registered electrical contractor and a TNB application, but it can take months and the cost varies. Large loads may need a substation on site. Agree in writing who pays and how long it will take before you sign.
Does this calculator replace an electrical engineer?
No. It is a quick estimate to shortlist factories. The final supply size must be worked out by a registered electrical engineer and approved by TNB.
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