Install top-notch snap-acting HVAC contactors from Black Hawk Supply, in any position you require for remote control of air conditioning, heating and also for ventilation systems. At Black Hawk supply, you can shop for magnetic AC switching relays, heavy-duty enclosed fan contactors and for conduit connector enclosed switching contactors. Here you can also explore different transformer combinations, including conduit box or unit mount, junction box mount contractors and conduit or unit mount for hydronic applications. It provides you with best HVAC contractors that you need for your commercial and residential purposes to control all your heating, ventilation and air conditioning systems.
HVAC relays/contactors are very similar to the switch. In cooling and heating systems, the contactors are mainly used to turn the system on and off the high voltage components such as compressors, motors, and other high voltage components. When thermostat reaches a certain point of temperature that you set, a transformer, which is of 24V energizes the contactor that has an inbuilt coil. When this in-built coil is energized, it just acts like a magnet and pulls out the legs of the contactor down by making contact on both sides completing a circuit. If there is zero voltage from the transformer, then the coil lets go of the legs by opening the circuit. This whole process allows a thermostat to control all the high voltage components in an HVAC system just with the use of 24 volts. Contactors generally come in three styles they are: single pole, double pole, and triple pole. HVAC contactors can be pressed down by yourself completing the circuit, and this is often used to test them in the field. Another way that is used to test it is to know whether the voltage is going from one side to the other side or not. AC voltage from the fuse box will go into one side, and it will always be hot. The other side of it will only have enough voltage when the contactor is engaged and working. When it is on, the same voltage should be there on both sides, while you measure with a multimeter. The third way to test a contactor is to see for continuity when it is engaged by the transformer. The main problem with a bad contactor is pits and builds up where the legs touch. This can be seen by black burn marks and pit. Also, you have to measure out the voltage from the transformer to maintain the correct voltage. A bad transformer not sending out exact correct voltage will never let the transformer switch on.