Packaged heat pump
The refrigeration circuit heats and cools. Supported models may accept electric resistance heat for auxiliary or emergency operation.
Packaged HVAC Electrical Requirements
Packaged HVAC electrical requirements depend on the exact unit and heating method.
One outdoor cabinet can contain the compressor, fans, blower, controls, and either heat-pump components or gas-heating equipment. Optional electric auxiliary heat can add a much larger, separate electrical load.
Technical review: August 2026 • Current catalog + governed MRCOOL documents
Quick answer: Identify whether the unit is a packaged heat pump or a gas/electric package unit, then match the complete model number. Use the model's published voltage, phase, MCA, and MOP - plus the exact heat-kit data when auxiliary electric heat is installed. Do not size a package-unit circuit from tonnage alone.
What kind of package unit do you have?
Gas/electric package unit
Gas provides primary heat, while electricity operates the compressor, outdoor fan, supply blower, ignition/control system, and documented gas-section support loads.
What this means for you: the cabinets may look similar, but their heating architecture and electrical planning are not interchangeable.
What is electrically inside a packaged system?
CompressorMoves refrigerant for cooling and, in a heat pump, heating.
Outdoor fanMoves outdoor air across the coil.
Supply blowerMoves conditioned air through the duct system.
ControlsCoordinate safeties, staging, ignition, defrost, and thermostat calls as applicable.
Optional heatResistance heat only where the exact unit and kit are compatible.
Technical: published MCA and MOP account for the equipment configuration evaluated by the manufacturer. They are not obtained by adding catalog amp ratings or by guessing from nominal capacity.
Packaged heat pump vs. gas/electric package
Packaged heat pump
Heating: compressor-driven refrigeration cycle.
Optional: compatible electric auxiliary heat.
Electrical implication: the auxiliary heater can materially increase demand and may introduce a separate heat circuit arrangement.
vs.
Gas/electric package
Heating: gas combustion.
Electrical support: blower, controls, ignition, safeties, documented inducer functions, plus the cooling compressor and fan.
Electrical implication: gas supplies the heat energy; electricity still runs the machinery and controls.
If it heats with gas, why does it still need electricity?
Plain English: gas makes the heat, but electricity moves the air, starts and supervises combustion, and powers the air-conditioning side.
Professional detail: the reviewed gas-package documents identify electrical compressor, outdoor-fan, indoor-blower, ignition/control, and gas-heating support functions. Exact components and control sequence remain model-specific. A gas/electric package unit does not have the same resistance-heat demand as an electric heat kit.
Choose the exact MRCOOL packaged family
VersaPro packaged heat pump
Horizontal R-454B models with published base-unit MCA/MOP and compatible 5, 7.5, 10, 15, and 20kW heat-kit options by capacity.
Shop packaged unitsVersaPro gas/electric
Horizontal/downflow gas package units with published cooling capacity, gas input/output, MCA, and MOP.
Shop gas package unitsUniversal packaged heat pump
Current live R-32 inverter models use the MDPH180...D model pattern and support documented 6, 9, and 12kW kit models.
Shop Universal package units
Still-listed earlier generations: exact R-410A VersaPro rows appear below because they remain active in the storefront catalog. Older Signature storefront titles have model-suffix conflicts with the available official specification rows, so this page does not borrow numbers across those suffixes.
MCA and MOP answer different questions
MCA
Plain English: Minimum Circuit Ampacity tells the electrician how much current the circuit wiring must be able to safely carry.
Technical: MCA is the manufacturer-published minimum conductor ampacity for that equipment or heater circuit, subject to conductor type, temperature ratings, installation conditions, code, and the authority having jurisdiction.
MOP / MOCP / max fuse-breaker
Plain English: This is the largest protective-device rating the manufacturer permits for the listed equipment or circuit.
Technical: Source documents use MOP, maximum overcurrent protection, or maximum fuse/breaker. This page preserves the source meaning and does not invent a preferred breaker size.
Do not size wire from the breaker number alone. Start with the exact model and MCA, then apply nameplate instructions, conductor conditions, current code, and professional design.
VersaPro R-454B packaged heat-pump electrical data
| Capacity | Model | Cooling | Supply | MCA | MOP | Compatible auxiliary heat |
|---|---|---|---|---|---|---|
| 2 ton | MPH241HO13C | 22,800 Btu/h | 208/230V, 1 phase, 60Hz | 17.9A | 25A | MHK05PC / MHK07PC / MHK10PC |
| 2.5 ton | MPH301HO13C | 28,200 Btu/h | 208/230V, 1 phase, 60Hz | 24.4A | 30A | MHK05PC / MHK07PC / MHK10PC / MHK15PC |
| 3 ton | MPH361HO13C | 34,200 Btu/h | 208/230V, 1 phase, 60Hz | 27.1A | 35A | MHK05PC / MHK07PC / MHK10PC / MHK15PC |
| 3.5 ton | MPH421HO13C | 40,500 Btu/h | 208/230V, 1 phase, 60Hz | 29.9A | 40A | MHK05PC / MHK07PC / MHK10PC / MHK15PC / MHK20PC |
| 4 ton | MPH481HO13C | 46,500 Btu/h | 208/230V, 1 phase, 60Hz | 36A | 45A | MHK05PC / MHK07PC / MHK10PC / MHK15PC / MHK20PC |
| 5 ton | MPH601HO13C | 56,500 Btu/h | 208/230V, 1 phase, 60Hz | 48.6A | 60A | MHK05PC / MHK07PC / MHK10PC / MHK15PC / MHK20PC |
Plain English: MCA rises from 17.9A on the 2-ton model to 48.6A on the 5-ton model. The MOP is not a tonnage lookup; each complete model has its own published value.
Source: VersaPro R-454B Packaged Heat Pump Specifications, pages 3, 4, 6.
VersaPro R-454B gas/electric package electrical data
| Capacity | Model | Cooling | Supply | MCA | MOP | Gas input / output |
|---|---|---|---|---|---|---|
| 2 ton | MPG24S060MO13C | 22,800 Btu/h | 208/230V, 1 phase, 60Hz | 18.8A | 25A | 60,000 / 48,000 |
| 2.5 ton | MPG30S060MO13C | 28,400 Btu/h | 208/230V, 1 phase, 60Hz | 21.5A | 30A | 60,000 / 48,000 |
| 3 ton | MPG36S090MO13C | 34,000 Btu/h | 208/230V, 1 phase, 60Hz | 25.2A | 40A | 90,000 / 72,000 |
| 3.5 ton | MPG42S090MO13C | 40,000 Btu/h | 208/230V, 1 phase, 60Hz | 29.9A | 45A | 90,000 / 72,000 |
| 4 ton | MPG48S090MO13C | 47,000 Btu/h | 208/230V, 1 phase, 60Hz | 36.4A | 50A | 90,000 / 72,000 |
| 5 ton | MPG60S110MO13C | 57,000 Btu/h | 208/230V, 1 phase, 60Hz | 41.4A | 60A | 110,000 / 88,000 |
Plain English: gas provides heating energy, but these units still publish MCA and MOP because the compressor, fans, blower, and controls require electrical power.
Source: VersaPro R-454B Gas Package Unit Specifications, pages 3, 4.
Universal R-32 inverter packaged heat-pump electrical data
| Capacity | Model | Cooling | Supply | MCA | MOP | Compatible auxiliary heat |
|---|---|---|---|---|---|---|
| 3 ton | MDPH18036D | 34,000 Btu/h | 208/230V, 1 phase, 60Hz | 35A | 40A | MDPHK06D / MDPHK09D / MDPHK12D |
| 4 ton | MDPH18048D | 47,000 Btu/h | 208/230V, 1 phase, 60Hz | 39.1A | 45A | MDPHK06D / MDPHK09D / MDPHK12D |
| 5 ton | MDPH18060D | 56,000 Btu/h | 208/230V, 1 phase, 60Hz | 39.1A | 45A | MDPHK06D / MDPHK09D / MDPHK12D |
Plain English: the 4- and 5-ton models share the same published MCA/MOP in the reviewed manual; that is a documented model relationship, not a tonnage assumption.
Source: Universal R-32 DC Inverter Package Unit Installation & Owner's Manual, pages 15, 16, 17, 18, 19.
R-410A VersaPro models currently visible in the catalog
Packaged heat pumps
| Capacity | Model | Cooling | Supply | MCA | MOP | Compatible auxiliary heat |
|---|---|---|---|---|---|---|
| 2 ton | MPH241H413B | 22,800 Btu/h | 208/230V, 1 phase, 60Hz | 15A | 20A | MHK05PB / MHK07PB / MHK10PB |
| 2.5 ton | MPH301H413B | 30,000 Btu/h | 208/230V, 1 phase, 60Hz | 18A | 25A | MHK05PB / MHK07PB / MHK10PB / MHK15PB |
| 3 ton | MPH361H413B | 34,200 Btu/h | 208/230V, 1 phase, 60Hz | 22.6A | 35A | MHK05PB / MHK07PB / MHK10PB / MHK15PB |
| 3.5 ton | MPH421H413B | 40,500 Btu/h | 208/230V, 1 phase, 60Hz | 24.2A | 35A | MHK05PB / MHK07PB / MHK10PB / MHK15PB / MHK20PB |
| 4 ton | MPH481H413B | 46,500 Btu/h | 208/230V, 1 phase, 60Hz | 26.8A | 40A | MHK05PB / MHK07PB / MHK10PB / MHK15PB / MHK20PB |
| 5 ton | MPH601H413B | 56,500 Btu/h | 208/230V, 1 phase, 60Hz | 34.9A | 55A | MHK05PB / MHK07PB / MHK10PB / MHK15PB / MHK20PB |
Source: VersaPro R-410A Packaged Heat Pump Specifications, pages 3, 4, 11.
Gas/electric package units
| Capacity | Model | Cooling | Supply | MCA | MOP | Gas input / output |
|---|---|---|---|---|---|---|
| 2 ton | MPG24S060M413B | 24,000 Btu/h | 208/230V, 1 phase, 60Hz | 19A | 25A | 60,000 / 48,000 |
| 2.5 ton | MPG30S060M413B | 30,000 Btu/h | 208/230V, 1 phase, 60Hz | 21A | 30A | 60,000 / 48,000 |
| 3 ton | MPG36S090M413B | 36,000 Btu/h | 208/230V, 1 phase, 60Hz | 23A | 35A | 90,000 / 72,000 |
| 3.5 ton | MPG42S090M413B | 42,000 Btu/h | 208/230V, 1 phase, 60Hz | 28A | 40A | 90,000 / 72,000 |
| 4 ton | MPG48S090M413B | 48,000 Btu/h | 208/230V, 1 phase, 60Hz | 31A | 50A | 90,000 / 72,000 |
| 5 ton | MPG60S110M413B | 60,000 Btu/h | 208/230V, 1 phase, 60Hz | 37A | 60A | 110,000 / 88,000 |
Source: VersaPro R-410A Gas Package Unit Specifications, pages 3, 4.
Why some still-listed Signature rows are not given a borrowed breaker number
Current storefront titles include Signature heat-pump models ending in ...M414A and gas/electric models ending in ...M414A. The available official specification sheets reviewed for this project use ...M414B heat-pump rows and ...M414A-2 gas/electric rows.
Safety decision: because the suffix is part of the model identity, this page does not transfer the published numbers to a different storefront suffix. For those units, use the actual nameplate and the exact matching revision supplied with the equipment.
Governance sources: Signature Packaged Heat Pump Specifications, pages 2, 14; Signature Gas/Electric Packaged Unit Specifications, pages 2.
Why electric backup heat can change the electrical requirements
Heat pump only
Compressor + fans + blower
The base-unit table publishes the package equipment MCA and MOP.
+
Auxiliary resistance heat
Separate high-load heater data
The compatible heater adds its own published amperage, MCA, protection, stages, and separate-power instructions.
| Heat-kit model | kW | Heat stages | Amps | MCA | Max fuse/breaker |
|---|---|---|---|---|---|
| MHK05PB / MHK05PC | 3.8 / 5 | 1 | 18.1 / 20.8A | 23 / 26A | 25 / 30A |
| MHK07PB / MHK07PC | 5.6 / 7.5 | 1 | 27.1 / 31.3A | 34 / 40A | 35 / 40A |
| MHK10PB / MHK10PC | 7.5 / 10 | 1 | 36.1 / 41.7A | 46 / 53A | 50 / 60A |
| MHK15PB / MHK15PC | 11.3 / 15 | 2 | 54.2 / 62.5A | 68 / 79A | 70 / 80A |
| MHK20PB / MHK20PC | 15 / 20 | 2 | 72.3 / 83.4A | 91 / 105A | 100 / 110A |
What this means for you: a 5kW option has a much different electrical profile from a 20kW option. The 15kW and 20kW kits are two-stage in the source table. The source also instructs that the optional heater uses a separate power supply rather than being connected to the unit's single supply line. A two-stage heater is not automatically two heater branch circuits; follow the exact kit wiring diagram.
Sources: VersaPro R-454B Packaged Heat Pump Specifications, pages 3, 4, 6; VersaPro R-410A Packaged Heat Pump Specifications, pages 3, 4, 11; VersaPro R-410A Packaged Heat Pump Installation Manual, pages 27, 28, 29, 30.
Universal R-32 distinction: the current manual names compatible MDPHK06D, MDPHK09D, and MDPHK12D for all listed models. The reviewed manual does not publish their heater-circuit MCA/MOP table, so those numeric values are not invented here; verify the kit nameplate and kit-specific instructions.
How many breakers does a package unit need?
Direct answer: it depends on the exact unit and installed heat configuration. The base package equipment has its published circuit requirements. In the reviewed VersaPro manual, a compatible electric heat kit uses a separate power supply from the base unit and has its own heater-circuit MCA and maximum protection.
A gas/electric unit does not use an electric resistance kit for its primary gas heat. A packaged heat pump without auxiliary electric heat does not have the same electrical picture as that same family with a large heater installed. Heat stages are not a substitute for counting documented supply circuits.
Never answer from tonnage alone. Read the package-unit nameplate, installed heat-kit model/nameplate, latest wiring diagrams, and applicable code.
Three model-level examples
Heat pump, no auxiliary heat
- Model
- MPH301HO13C
- Supply
- 208/230V, 1 phase, 60Hz
- MCA / MOP
- 24.4A / 30A
- Heating
- Heat-pump refrigeration cycle
Takeaway: plan from the base-unit row only when no electric heater is installed.
Heat pump + 15kW class kit
- Package unit
- MPH361HO13C; MCA 27.1A; MOP 35A
- Compatible kit
- MHK15PC
- Heater-circuit data
- 11.3/15kW; MCA 68/79A; max 70/80A at 208/230V; 2 heat stages; separate heater supply
Takeaway: base-unit and heater requirements remain separate planning facts.
Gas/electric package
- Model
- MPG36S090MO13C
- Supply
- 208/230V, 1 phase, 60Hz
- MCA / MOP
- 25.2A / 40A
- Gas heat
- 90,000 Btu/h input; 72,000 Btu/h output
Takeaway: gas provides heat, while the unit still needs its documented electrical circuit.
Power wiring and thermostat wiring do different jobs
Big wires power the equipment
Line-voltage conductors supply the compressor, motors, controls, and any separately supplied compatible electric heater.
+
Small thermostat wires tell it what to do
Reviewed package-heat-pump documentation identifies functions including R, C, Y, B, W/W1, and G. Gas/electric controls are documented for the exact packaged gas unit and thermostat application.
This is not a universal point-to-point terminal map. Terminal use, reversing-valve logic, staging, and auxiliary/gas heat calls differ by family and exact wiring diagram.
Why does the nameplate say 208/230V when an electrician says 240V?
208V
A supply voltage commonly encountered in certain building electrical systems.
230V nameplate
The utilization-voltage rating used by the manufacturer for this equipment family.
“240V” at home
Common field language for the residential supply class. Match the actual supply to the nameplate range; do not wire from casual wording alone.
The disconnect is not a substitute for model-specific circuit design
Reviewed manuals call for a branch-circuit disconnect near, within sight of, and readily accessible to the unit, subject to applicable rules. They also direct the installer to use the unit rating-plate circuit ampacity and approved overcurrent protection.
Do not size the wire from the breaker number alone. Use the exact model, MCA, MOP, current manual, nameplate, conductor conditions, and the authority having jurisdiction. A published 25A, 35A, 45A, or other standard protective-device value is not permission to skip conductor calculations.
Equipment circuit vs. whole-house service capacity
Equipment circuit requirement
“What does this exact package unit and installed heat option require?” Answered by the nameplates, MCA/MOP tables, wiring diagrams, and applicable code.
Whole-house service capacity
“Can the service and panel support this HVAC equipment plus everything else?” Answered by a proper load calculation across the home.
A large electric-heat option may matter to service planning. It does not automatically prove that a 200A service, panel replacement, or service upgrade is required.
What information does your electrician actually need?
- Complete package-unit model number and equipment type: heat pump or gas/electric.
- Voltage, phase, and frequency from the nameplate.
- Exact auxiliary heat-kit model, if installed or planned.
- Clear photos of the unit and heat-kit nameplates.
- Current installation manual, specification table, and wiring diagram.
- Thermostat/control documentation where relevant.
Bad: “It is a 3-ton package unit.”
Good: “It is model MPH361HO13C with heat kit MHK15PC.”
Packaged HVAC electrical questions
Does a package unit need its own breaker?
The reviewed manuals call for a dedicated/independent equipment circuit and an accessible disconnect. Final design follows the exact model, nameplate, current manual, and applicable code.
How many breakers does a packaged heat pump need?
There is no tonnage-only answer. The base unit has model-specific requirements, and the reviewed compatible VersaPro electric heater uses a separate heater supply with its own MCA and maximum protection.
Does a gas package unit still need electricity?
Yes. Electricity operates the compressor, outdoor fan, blower, controls, ignition/safeties, and documented gas-section support equipment; gas supplies the primary heating energy.
Does adding electric heat change the requirement?
Yes. The reviewed VersaPro heater table ranges from 5kW-class to 20kW-class options, with substantially different MCA and maximum protection values.
Can a package unit use multiple circuits?
Yes. The reviewed VersaPro arrangement keeps the base-unit supply separate from the compatible heater supply. Do not assume the same arrangement across families; follow the exact wiring diagram.
What does MCA mean?
Minimum Circuit Ampacity is the manufacturer-published starting point for the minimum conductor ampacity of that equipment or heater circuit.
What does MOP or MOCP mean?
It is the manufacturer-published maximum overcurrent-protection value. It does not replace the MCA or the final conductor/circuit design.
Can I determine breaker size from tonnage?
No. Models of similar capacity can have different MCA/MOP values, and heating type or auxiliary heat can change the electrical architecture.
Why does the unit specify 208/230V?
That is the manufacturer's supported utilization-voltage range for these models. The measured supply and nameplate must be matched by the installer.
Do heat strips need additional electrical capacity?
Yes. Resistance heat can be a major additional load. Use the exact compatible kit's nameplate, MCA/MOP data, and wiring instructions.
Does electric heat automatically require a service upgrade?
No. It may affect service planning, but only a complete load calculation can determine whether the panel or service needs work.
What is the final authority?
The exact unit and heat-kit nameplates, latest matching MRCOOL documents, applicable code, and the authority having jurisdiction control the installation.
Take the next useful step
- Shop MRCOOL packaged units
Compare current heat-pump and gas/electric product paths. - MRCOOL documentation hub
Find current model-specific manuals and supporting documents. - Central ducted electrical requirements
Use the separate split-system reference for condensers, air handlers, and heat kits. - Mini split electrical requirements
Use the ductless model-specific electrical reference. - Electrical accessories
Browse disconnect and surge-protection options after requirements are confirmed. - HVAC sizing and BTU guide
Keep comfort sizing separate from circuit sizing.
Planning reference: specifications and available products can change. Verify the exact equipment nameplate and latest MRCOOL documentation before installation. Electrical and gas work must follow applicable requirements and be completed by the qualified professionals responsible for the installation.