How to Install a 94-388 Contactor
- 1). Turn off the circuit breakers to both air conditioning units. The contactor receives its low-voltage signal from the inside unit and its high-voltage power feed from its circuit breaker. The inside unit's circuit breaker often has a "Furnace," "Air Handler" or "Blower" identification tag. The outside unit's circuit breaker usually uses a "Condenser," "Air Conditioner" or "Heat Pump" label.
- 2). Remove the screws holding the condenser's electric panel cover in place, using the correct screwdriver. The cover protects the electrical compartment from moisture. Remove the cover.
- 3). Inspect and understand the condenser's wiring diagram. Usually condenser manufacturers place the wiring diagram on a sticker located on the inside of the electrical panel's cover. The wiring diagram lists the condenser's components, its wire colors and the wire terminal locations on each component.
- 4). Inspect and understand the 94-388 contactor. The coil, located below the bus bars, has a set of wire terminals on each side of the contactor. The high-voltage leg considered "L1," the definite-purpose leg, contains a solid metal strip between its wire terminals. The high-voltage leg considered "L2" uses the spring-loaded bus bar.
- 5). Mount the 94-388 to the condenser's electrical compartment, using the mounting screws located near the place where the circuit breaker's wires enter the unit. Tighten the screws with the proper screwdriver, usually a 5/16-inch hex screwdriver.
- 6). Push the interchangeable low-voltage wire's wire connectors onto the 94-388's coil terminals, using needle-nose pliers to force the connectors onto the terminals. Place one low-voltage wire connector on each coil terminal. The thin-gauge low-voltage wires provide a control signal from the thermostat.
- 7). Slip the circuit breaker's black wire under one of the 94-388's L1 terminal screws; use the terminal screw closest to where the circuit breaker wires enter the unit. Tighten the screw with a Phillips screwdriver.
- 8). Insert the circuit breaker's white wire under one of the 94-388's L2 terminal screws; use the terminal screw closest to where the circuit breaker wires enter the unit. Tighten the terminal screw, using the Phillips screwdriver.
- 9). Position the compressor's black wire under the 94-388's other L1 terminal screw and tighten the screw with the Phillips screwdriver. The black wire in the condenser's electrical compartment with the thick insulation connects to the compressor's "C" or "Common" terminal.
- 10
Push the terminal connectors on the remaining black-colored wires onto the 94-388's L1 1/4-inch pins, using the needle-nose pliers to force the connectors onto the pins. All of the condenser's black wires connect to the contactor's L1 leg. - 11
Slide the wire connected to the compressor's "R" terminal under the 94-388's remaining L2 terminal screw and tighten the terminal screw with the Phillips screwdriver. Usually the compressor's "R" terminal uses a red-colored wire. - 12
Push the wire connectors on the condensing unit's remaining high-voltage wires onto the 1/4-inch pins located under the 94-388's L2 terminal with the compressor's "R" terminal wire. Push the connectors onto the pins with the needle-nose pliers. The remaining wires usually use orange, red or white insulation. - 13
Compare the 94-388's wire connections with the wire diagram. All wire colors and connections must match the wire diagram. - 14
Replace the electrical compartment's cover. Lock the cover in place with its screws.
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