NEC 220.87 · Article 440
Can My Panel Handle a Heat Pump?
The compressor is a modest load, usually MCA 15 to 30A, so it fits most services easily. The catch is electric backup heat. Here is the fit threshold by compressor MCA and service size, and why the strip heater is the number that actually decides the job.
Will the compressor fit? By MCA and service
Each cell is the highest existing metered demand your service can already be carrying and still take the compressor. This is the compressor alone; add any electric backup heat separately.
| The load | Adds | 100A service | 125A service | 150A service | 200A service |
|---|---|---|---|---|---|
| 15A MCA (1.5-2 ton) | 15A | ≤ 68A | ≤ 88A | ≤ 108A | ≤ 148A |
| 20A MCA (2-3 ton) | 20A | ≤ 64A | ≤ 84A | ≤ 104A | ≤ 144A |
| 25A MCA (3-4 ton) | 25A | ≤ 60A | ≤ 80A | ≤ 100A | ≤ 140A |
| 30A MCA (4-5 ton) | 30A | ≤ 56A | ≤ 76A | ≤ 96A | ≤ 136A |
Each cell is the highest 12-month metered demand (NEC 220.87) your service can already be carrying and still take the new load: it fits when your metered peak is at or under that number. “Upgrade / manage” means the new load alone fills the service, so it needs demand management or a service upgrade regardless of the existing draw. Computed at 125% of the metered demand per NEC 220.87; the nameplate rating of your unit governs the “adds” figure.
The backup heat is the real load
The outdoor compressor draws little, but the indoor air handler's electric resistance backup can be 5 to 20 kW, which is 20 to 83A at 240V, several times the compressor. The NEC 220.87 check has to include that strip load, and on a 100A or 150A service it is almost always the number that forces an upgrade, not the heat pump itself. The fix is upstream: size the heat pump so it holds capacity in your climate and needs little or no strip heat. Run that on the cold-climate capacity tool, size the compressor circuit on the MCA/MOCP calculator, and check the whole panel on the load calculator.
Frequently Asked Questions
Can my 200A panel handle a heat pump?
Almost always, for the compressor itself. A residential heat pump is a modest new load, usually a nameplate MCA of 15 to 30A, and by NEC 220.87 a 25A-MCA unit fits a 200A service as long as your 12-month metered peak is at or under 140A. The real question is backup heat: an air handler with electric resistance strips can add 20 to 40A on top of the compressor, and that combined load is what you check against the service.
Can a 100A panel handle a heat pump?
The compressor alone, usually yes: a 25A-MCA heat pump fits a 100A service up to a 60A metered peak. The problem on a 100A service is almost never the compressor and almost always the electric backup heat. A 10 kW strip heater adds about 42A, which on top of the existing load frequently pushes a 100A service over. Cold-climate heat pumps that reduce or eliminate strip heat are the way to keep the load down; size the heat first.
Does a heat pump with electric backup heat need more panel capacity?
Yes, and this is the part that catches people. The outdoor compressor is a small load, but the indoor electric resistance backup (heat strips) can be 5 to 20 kW, which is 20 to 83A at 240V. The NEC 220.87 check has to include that strip load, and it is usually what decides whether a 100A or 150A service needs an upgrade. Sizing the heat pump to hold capacity in your climate, so it needs little or no strip heat, is the cleanest way to keep the panel load down.
What breaker and wire does a heat pump need?
Sized from the nameplate, not a rule of thumb. A heat pump condenser lists a minimum circuit ampacity (MCA) and a maximum overcurrent protection (MOCP or max breaker); the conductor is sized to the MCA and the breaker to the MOCP, per NEC Article 440. A typical 3-ton unit is around 25A MCA on a 30 or 35A breaker with #10 copper. The MCA/MOCP calculator sizes the exact circuit.
Related Calculators
MCA / MOCP Breaker Calculator
Size the breaker, wire, and ground for a heat pump or AC condenser from the nameplate MCA and MOCP.
Cold-Climate Heat Pump Capacity
Capacity at 5F and the backup heat you actually need, so you can keep the strip load down.
Dwelling Load Calculator
Run the full NEC 220.87 check including the backup-heat load, every step shown.
Can My Panel Handle It?
The same check for an EV charger, tankless water heater, hot tub, or induction range.