Home Load Calculator Before Adding an AC

Can my meter handle another AC?

The meter itself only records units; what limits you is the sanctioned load in kW on your bill, the main breaker at the meter and the service cable into the house. Add the AC's running watts to what already runs together and compare the new total with the sanctioned kW. In the default case 1,500 W plus a Split AC 1.5 ton inverter makes 2,950 W, which is 148% of a 2 kW connection: too much.

On a 5 kW connection the same home is at 59% with 2.05 kW of headroom, so the answer depends on the sanctioned load far more than on the meter. Also check that the main breaker rating is above the new current of 16 A.

How do I add an AC to my house load?

First find the load running now: use the home load calculator with only the appliances that are on at the same time on a summer evening, or add up their labels. Then pick the AC. The calculator adds the AC's running watts, which is the right number for the check because on a hot afternoon an inverter AC runs near its rated input for long stretches; its lower average draw is for the electricity bill, not for the load.

The result shows the new total in watts and amps, how much of the sanctioned load it uses, and the MCB rating for the AC's own circuit. If you plan a second AC, run the calculator again with the first result as the load running now.

What sanctioned load do I need for an AC?

The sanctioned load must be at least the new total in kW, rounded up to a whole kW. With 1,500 W of other load and a Split AC 1.5 ton inverter the new total is 2.95 kW, so a 2 kW connection is not enough and the next whole kW above 2.95 kW is the minimum to apply for. A small home with 800 W of fans, lights and a fridge can add a Split AC 1 ton inverter on 2 kW at 85%.

Apply for a little more than the minimum if you expect to add appliances, but remember the fixed charge on the bill is per sanctioned kW, and that 5 kW or more puts the connection on the time-of-use tariff.

What is the AC load on a single phase supply in amps?

An AC's own current is its running watts ÷ (volts × power factor). At 230 V and a 0.8 power factor a Split AC 1 ton inverter draws about 4.9 A, a Split AC 1.5 ton inverter about 7.9 A and a Split AC 1.5 ton non-inverter about 9.8 A while running.

The non-inverter compressor is the one to watch: its start surge of 5,400 W pushes the whole house to 40.2 A for a moment in the example below, which is what trips a main breaker that is already near its rating.

What home wiring does a new AC need?

A dedicated circuit from the distribution board: its own copper cable of at least 2.5 mm² (7/29 in Pakistani sizes), its own MCB and a proper earth. Never run an AC from a socket circuit shared with other appliances. For a Split AC 1.5 ton inverter that is a 16 A type C MCB on 2.5 mm² (7/29) cable; the AC wire size page linked below sizes the cable and breaker at the AC's maximum input with a safety margin and checks the voltage drop over your cable run, so use that for the final sizes.

If the house is older and the main cable or distribution board is already warm or discoloured, have an electrician check it before adding the AC, whatever this calculator says.

Can my meter take two ACs?

Run the check twice. The 1,500 W home above reaches 2,950 W with the first Split AC 1.5 ton inverter; a second one on top takes it to 4,400 W and 23.9 A, which is 88% of a 5 kW connection. Two 1.5 ton ACs plus normal household load therefore need a 5 kW sanctioned load in practice, and each AC needs its own circuit and MCB.