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PARTS OF THE CONDENSING UNIT:

Motor Starting Contactors:

A contactor is sometimes called relay or starter. Its function is to interrupt the incoming 230 volts and wait until the call from the thermostat to close its contacts and thus turn on the condenser fan and compressor. The thermostat, upon demand, will send 24 volts (usually) to the magnetic coil of this contactor and thus pull down on the assembly for the contacts to close and the 230 volts then rushes on to the motor, etc.

motor run capicator One of the more important things about the contactor is the contact points. The are usually made of some very soft alloy ranging from gold to cadmium. Sometimes the contact points will become so pitted and out of original shape that they are not making good contact. THIS IS OF PARAMOUNT CONCERN. This is the device that sends the correct voltage and current to the fan motor and the compressor. A compressor is an important and very expensive part of the cooling system. In fact, it is the heart of the system. It will suffer greatly if the contact points do not supply instantly and appropriately the right voltage and current to it.

If you think you need it, refer back to the rules of safety in the first page of Condensers for the right way to make sure the 230 VAC current is turned off.

Examine your contacts in your contactor. If you think there is damage or obstructions in them, then you may have to clean them. You will have to more than likely remove a spring that hold them in place. Try very hard to not let it fly out of the contact and thus you may loose it. Remove the contact bar. Examine the surfaces. You may use a very fine file to lightly buff-up the surfaces or rub them gently with a soft abrasive. Be sure to maintain their original shape and don't file away too much of the alloy. Blow out any debris or insects or grass shavings from the contactor and the control panel and then replace the contact bar and the spring. (You didn't loose it did you?)

Fire ants are one of the most common obstructions to the contacts. If you have never see it, you might not believe it. They are attracted to the electricity and especially the contact. Sometimes as many as a handful will die in and around the contactor and control panel. Their bodies obstruct the flow of current if they are under the contacts of the contactor bar--and they often are. Spiders are also a suspect when problems occur.

If you want to save yourself a lot of work, just replace the contactor and be done with it. Many, many technicians and other experts do not recommend cleaning of the contacts. I personally find that I have great success in cleaning them and save my customers a lot of money in the process, but if you are in doubt, just replace the contactor and be sure. The cost will range from $20 to $65 depending on the size of the contactor.

You must, if you replace it, be very careful to get the wires in exactly the right places. Some contactors look and operate very differently and can be confusing. Get the exact match if you can and make sure also that the electrical coil for it is the right voltage.


Other Parts Of The Condenser
Blade Assembly Motor Mounting Bracket
Capacitors Contactors Condenser Coils
Line Valves Compressor Feet Compressors



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