An ampere (A), also called amp, is the unit of electrical current flow representing the amount of charge moving through a circuit per second. Amperage is critical for sizing electrical wiring, breakers, and protection devices in HVAC and solar installations. A typical residential air conditioning system draws 15 to 20 amperes during operation.
Technical Details
One ampere represents 1 coulomb of electrical charge flowing per second. Current is measured using an ammeter or clamp meter. Ohm’s Law states that amperage equals voltage divided by resistance (A = V/R). An HVAC compressor rated at 240 volts and 20 amperes draws 4.8 kilowatts of power. Solar inverters must be sized to handle the amperage output of photovoltaic arrays, typically 10 to 100 amperes.
HVAC Installation Standards
The National Electrical Code (NEC) requires circuit breakers and wiring sized for 125 percent of continuous load amperage. A 20-amp compressor requires a 25-amp breaker and 10-gauge wire. Undersized circuits create fire hazards and reduce system performance.
Equipment Coordination
Matching amperage ratings across wiring, breakers, and equipment ensures safe operation. HVAC technicians verify amperage draw during commissioning to confirm proper system operation.