Electrician isn't coming back.

Disconnect Location (NEC 440.14): Must be within sight of the condenser (≤50 ft). If not visible, install a lockout/tagout disconnect at the unit and a remote one at the service panel.

Breaker/Wire Sizing (NEC 440.22, 440.23):

1. Nameplate FLA → Multiply by 1.25 for minimum breaker size. - Example: 20A FLA × 1.25 = 25A breaker minimum.
2. Wire Ampacity (NEC 440.22): - Size wire to 1.25 × FLA (same as breaker). - Use 75°C column if terminals rated for it (NEC 110.14). - Example: 25A required → #10 AWG copper (30A at 75°C).
3. Voltage Drop (optional but recommended): - Keep ≤3% for efficiency.

Key Notes:

• If nameplate specifies max breaker (e.g., 30A), use that instead of 1.25×FLA if higher.
• For heat pumps, account for reversing valve draw.
• Always verify local codes may be stricter.

Safety Warning: If unsure about electrical calculations or local requirements, hire a licensed electrician. Improper sizing can cause fire or equipment damage.

Disconnect Location (NEC 440.14):

• Sight & Distance: Must be within sight (visible, ≤50 ft) and readily accessible from the condenser.
• Mounting: Typically on the exterior wall adjacent to the unit. Not behind the unit. Not inside the house.
• Height: Working space per 110.26; center of grip ≤6'7" (404.8).

Sizing from Nameplate (NEC 440.4, 440.22, 440.35): Use only the nameplate values: MCA (Minimum Circuit Ampacity) and MOCP / Max Fuse/Breaker.

1. Conductor Ampacity (440.35, 310.16): Wire ampacity (75°C column) ≥ MCA. Example: MCA = 21.1A → #10 CU (30A @ 75°C) is minimum. #12 (25A) is too small. * Apply ambient temp correction (310.15(B)(1)) if in attic/roof (e.g., 140°F attic = 0.58 factor for 90°C wire).

1. Breaker / Fuse (440.22(A)): Size ≤ MOCP (Max Overcurrent Protection). Example: MOCP = 35A → Use 35A breaker (or 30A). Do not exceed MOCP. Breaker must be ≥ MCA (usually satisfied if MCA < MOCP). HACR rated breaker required.

1. Disconnect Rating (440.12(A)(1)): Ampere rating ≥ MCA. Horsepower rating ≥ compressor motor HP (or use FLA/LRA tables 430.248/250). * Standard 30A/60A non-fused pull-out usually fine for residential.

Grounding (250.134, 440.10):

• Equipment Grounding Conductor (EGC) sized per 250.122 based on breaker size (not MCA).
• 35A breaker → #10 CU EGC.
• Run EGC in same conduit/cable as conductors.

Critical: If nameplate says "Max Fuse 35A" and MCA 21.1A, you cannot use a 40A breaker or #8 wire "for voltage drop" unless MOCP allows 40A. Follow the plate exactly.