WHAT DOES THIS CONTACTOR DO?
The contactor's purpose is to send 230 Volts to the Air Conditioning Condenser or Heat Pump compressor, crankcase heater and out door fan motor.
24 Volts of power from your thermostat is applied to the (2) side terminals of the contactor (if it is a 24 volt system, see coil voltages below)(all residential systems use 24 volt coils) assuming your thermostat is calling for cooling in the case of an Air Conditioner. In the case of a Heat Pump 24 volt power is applied to these side terminals on Heat Or Cooling.
WHEN SHOULD THE CONTACTOR BE CHANGED?
Since the contactor is always arching from 240 volts being applied across the contacts, it doesn't take too many years before the contacts get burnt and pitted. This pitting doesn't allow a full 240 volts of power from getting to the compressor and fan motor. This is known as "Voltage Drop". This Voltage Drop results in HEAT which then leads to burnt wires and possibly burnt motors and compressors.
The other reason is because through the years of operation the plastic part that the contacts slide in, wear to the point that the contactor can stick closed which can lead to frozen evaporator coils and burnt out compressors. If you think your outdoor unit is still running even though the indoor fan has stopped, suspect a sticking contactor! Change it before you ruin a $1,000.00 or more expensive compressor!
When we are servicing your system and the service technician tells you the contactor is burnt or pitted or shows you a burnt or pitted contactor, have it changed out to keep from having future problems. Also, while we are there, it will save you another service call.
For 30 years, Action Heating and Air Conditioning has provided reliable air conditioning sales and service to residential and commercial customers in St.Augustine ,Northeast Florida and St. Johns air conditioning service . Contact us for expert advice when you’re upgrading.
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This Voltage Drop results in HEAT which then leads to burnt wires and possibly burnt motors and compressors.
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