Check the listing for details. A O Smith Century Air Compressor Motor Fits B386. Condition: New. Listed at 456.99 USD. A O Smith Century Air Compressor Motor K56A07A01 B385 B813 B386 This is a Brand New A.O Smith Century Air Compressor motor. The Motor is rated at 5 HP, 3600 RPM - 1 Speed, 230 Volts, 19.7 Amps, 56HZ Frame, Shaft Dimension: 7/8 x 2-1/4. It replaces the old part numbers listed below. Function: An electric motor converts electrical energy into mechanical energy. In an HVAC system, motors typically turn the air conditioning fan blade and the furnace blower motor. Newer high efficient motors, such as X13 and ECM motors, have "end caps" that control the motor speeds. These can be removed and replaced separately. Replaces Old Part #s: K56A07A01 B385 B813 B386 Repair Difficulty Level: Partial List of Units that Use This Item: Hit Ctrl + F and enter your model number for a quick search!