Air Conditioner Heat Pump Contactor Relay Switch

Air conditioner or heat pump pressure control pressure safety switches.

Air conditioner heat pump contactor relay switch.

Yuco cn pbc302 24 definite purpose contactor 30a 2p 24v 30 fla 40 res fits dp30c2p f ac heating contactor air conditioning contactor hvac contactor 4 6 out of 5 stars 73 11 99 11. Kung fu maintenance shows ac relay air conditioner contactor not pulling in five most often causes1 bad thermostat2 bad wiring3 bad contactor4 bad transf. That thermostat switch powered by a low voltage thermostat wiring 18 gauge circuit 24vac operates a physically separate relay switch or contactor switch located in the heater or air conditioner that turns on or off a heavier use wiring 14 12 or higher gauge circuit wiring a higher voltage 120vac or 240vac that in turn will operate the air conditioner or heat pump. An air conditioner uses relays to switch the system s high voltage parts on and off.

The contactor is the part of the air conditioner that controls the flow of electricity into the unit. Many air conditioners and heat pumps have low and high pressure safety switches on them to protect the unit from damage if the system pressure is too low low refrigerant charge or too high dirty outdoor unit or slow or bad condenser fan motor. The main ac power 115 230 volts is plugged onto one side coming from a breaker and the units blower motor compressor control board and everything else plugs onto the other side. When you turn off your ac the contactor goes up blocking power.

A coil of a contactor or relay should be checked for opens shorts or a measurable resistance. By the same token every time you turn on the air conditioner the contactor is lowered allowing electricity to power the system. Turns on high amp drawing equipment such as the compressor motor. Once your home reaches the temperature set on the thermostat the contactor goes up again.

If your unit is low on charge i find most often the safety switch will not allow the unit to start contactor will not engage. You will need to. An open coil will give a resistance reading of infinity and this coil should also be. If a coil is shorted the resistance will be 0 ohms and the coil should be replaced.

Also used in automotive air conditioning. Turns off the system at excessive refrigerant pressure and in some systems at too low pressure. The relay contains a low voltage coil and a high voltage switch sometimes called contact points when the thermostat switches on a low voltage signal energizes the appropriate relay. Air conditioner heat pump contactor relay switch.

The coil of a relay or contactor is used to close the contacts by creating a magnetic field that will pull the plunger into the magnetic field. The contactor relay in a heat pump is what controls the power coming into the unit.