Heat pump amp draw is 8 to 37 amps based on the heat pump size and to a lesser extent its efficiency.
This page on heat pump amp draw and related electrical topics begins with a heat pump amperage chart followed by a chart showing heat pump breaker size and wire size. Additional specifications follow.
Heat Pump Amps
How many amps does a heat pump use is answered in this chart. Find your heat pump size in tons or BTUs, and the right column shows the amp draw range.
1.5 – 5 Ton Heat Pump Amps
|Heat Pump Capacity||Cooling Btu||Amps|
|1.5 Ton||18,000 Btu||8 – 12 Amps|
|2 Ton||24,000 Btu||10 – 15 Amps|
|2.5 Ton||30,000 Btu||14 – 18 Amps|
|3 Ton||36,000 Btu||16 – 30 Amps|
|3.5 Ton||42,000 Btu||20 – 24 Amps|
|4 Ton||48,000 Btu||25 – 30 Amps|
|5 Ton||60,000 Btu||30 – 37 Amps|
What is the 3 ton heat pump amp draw?
16-30 amps are used by a 36,000 BTU heat pump. Most use between 16 and 25 amps.
What size is my heat pump? That question can be answered by looking at the model number on the jacket of the outside unit, the condensing unit.
Within the model number will be an 18, 24, 30, 36, 42, 48 or 60 corresponding to the number of BTUs x 1,000. For example, the Rheem RP2024B is a 24,000 BTU/2-ton heat pump.
Heat Pump Breaker and Wire Size
Equally important is knowing the right size breaker for the electrical panel. Breaker size is given in amps.
Wire size is important too, as each gauge is rated for carrying a number of amps. Once you know the amperage, you can select the right wire gauge.
1.5 – 5 Ton Heat Pump Breaker and Wire Size
|Heat Pump Capacity||Recommend Breaker Size||Wire Size|
|1.5 Ton||20 Amps||12 or 14 Gauge|
|2 Ton||25 Amps||10 or 12 Gauge|
|2.5 Ton||30 Amps||10 Gauge|
|3 Ton||30 Amps||8 or 10 Gauge|
|3.5 Ton||35 Amps||8 or 10 Gauge|
|4 Ton||45 Amps||6 or 8 Gauge|
|5 Ton||60 Amps||4 or 6 Gauge|
What’s the 5 ton heat pump breaker size?
A 60 amp breaker is required for a 5 ton heat pump.
You can usually find the right breaker size on the specification sheet for the heat pump. If it does not give you the actual “Breaker Size,” then look for a column called “Maximum Overcurrent Protection (amps)”. That’s the heat pump breaker size you should use.
It might simply be listed as an acronym, MOCP, which should also be listed on the plate on the condensing unit.
Why is wire size important? If the wire is too small, an electrical overload is possible and even likely. This will cause the wire to overheat, potentially melting the insulation around the wiring and leading to a fire hazard.
When the wire is the proper size, any overload will be responded to by the breaker. Most breakers trip at about 125% of their rated amperage when new. Over a period of time, that drops to around 100% or even less of rated amperage.
And in the end, it is much easier to switch out a breaker than to have to pull a wire and run a new wire.
Remember that wire size gets larger as the gauge size number gets smaller. An 8 gauge wire is thicker than a 12 gauge wire, for example.
Do I need to upgrade my electrical panel for a heat pump?
Yes, and the upgrade depends on the panel capacity and whether a breaker can be added.
Add a Breaker: Install a breaker in the panel of the proper size for your heat pump. This can be done if the panel has capacity that isn’t being used. For example, if it is a 200-amp panel and only 130 amps are being used, you have 70 additional amps – enough for any size heat pump from 1.5 to 5 tons.
Upgrade the Panel or Add a Subpanel: When you don’t have enough capacity left in the electrical panel to add the proper size breaker for a heat pump, then you’ll need a new panel. It is common to upgrade from a 100-amp to a 200-amp panel in older homes. In some cases, a small subpanel for the heat pump can be added.
What are locked rotor amps? Why are they so high?
We bring this up because you will see Locked Rotor Amps (LRA) on many heat pump specification charts, and it causes confusion.
They are essentially the same as starting amps – though even HVAC pros debate this. And yes, if the rotor freezes up, then the LRA amps will be constant, the circuit will trip, and your compressor will need replacement.
Locked rotor amps or starting amps are up to 5 times higher than running amps. But your heat pump has either a start capacitor or hard start kit that accommodates the extra heat pump amp draw.