What Size Breaker for Mini Split AC / Heat Pump?
A mini split ac / heat pump requires a 20A breaker with 12 AWG wire on a 240V dedicated circuit. This is a continuous load — breaker rated at 125% of actual draw.
🔌 Wire Length & Voltage Drop Check
Mini Split AC / Heat Pump Wiring Guide — NEC Requirements
Single-zone mini splits typically require a dedicated 15-20A/240V circuit. Multi-zone units may need 30-40A circuits. Always check the unit nameplate for MCA and MOP values.
Pro Tip
💡 Mini splits require a disconnect within sight of the outdoor unit per NEC 440.14. The line set and electrical can often share the same wall penetration.
Why a 20A Breaker?
The mini split ac / heat pump draws approximately 15A at 240V (3600W). As a continuous load (3+ hours), NEC 210.20 requires the breaker at 125%: 15A × 1.25 = 18.8A → 20A breaker.
Wire Sizing per NEC 310.16
For a 20A/240V circuit, 12 AWG copper is required per NEC Table 310.16 at 75°C. For runs over 75 feet, upsize to 10 AWG (long runs). Use our Wire Size Calculator and Voltage Drop Calculator.
Complete Parts List
To wire a mini split ac / heat pump circuit: a 20A double-pole breaker, 12 AWG NM-B cable (Romex) for interior runs or THHN/THWN-2 in conduit for exposed runs, a NEMA 14-30 receptacle (or hardwired), cable clamps, and appropriate junction boxes.
Disclaimer: This guide is for reference only. All electrical work must be performed by or verified by a licensed electrician. Local codes may differ from NEC.