10 Reasons why the Air Conditioner Contactor is not pulling in:
- The furnace power switch or the air handler breaker might be turned off. The furnace door might be loose and allowing the door safety switch to not be engaged. ...
- Make sure that your condensate pump safety switch has not tripped. ...
- You could have a bad thermostat or bad, loose thermostat wiring. ...
- You could have bad wiring. ...
- You could have a bad 5-minute delay board. ...
Why is my contactor not working properly?
There are any one of several things that could be causing your problem. One would be that the contactor is not getting enough voltage to the contactor coil. Your contactor should be getting a minimum of 24 volts AC to the contactor coil.
How do I know if my contactor coil is bad?
If you are getting 24 to 28 volts AC to the contactor coil and it is not closing then you have a bad contactor. I hope you can find and fix the problem soon! Steve Hi Mr. Jones! You would need to test and see if you are getting 24 volts AC to the contactor coil when your thermostat is calling for cooling.
What happens when the contactor coil gets below 24 volts?
If the contactor coil is getting below 24 volts then the contactor will chatter and not make good contact thus burning the contactor contacts up in a short period of time.
What does the contactor do on an air conditioner?
The contactor on the air conditioning unit is a switch that permits or stops power supply to the unit. It is a relay switch which directs electricity to the compressor of the air conditioner. When power is not needed, the contactor pulls the electrical contacts apart. It closes the contacts when something needs to be powered.
What causes a contactor to not engage?
3:0714:16AC Contactor Not Pulling In - 10 Reasons Why - YouTubeYouTubeStart of suggested clipEnd of suggested clipAll right so reason number one why your contactor plunger may not be pulling in is because yourMoreAll right so reason number one why your contactor plunger may not be pulling in is because your furnace power switch is off maybe you were changing the filter.
How do you know if you have a bad contactor?
A bad AC contactor can be identified by physical signs of deterioration, also known as pitting. Pitting occurs when the contactor has encountered extreme voltage and heat. A pitted contactor tends to stick, causing a continuous flow of electricity to the unit.
What causes a contactor to stay open?
The most common situation in contactor failures is contact sticking and coil burning. The reason for contact sticking; If more current is passed through the main power contacts than it can carry, the contacts will overheat after a while and the contacts may stick as a result of this warming.
What activates a contactor?
Contactors use 120 volt standard power to energize a magnetic coil, which causes a set of internal contacts to close and provide higher power to the equipment.
What happens if a contactor fails?
What Happens When The Contactor Is Faulty? When the contactor develops a fault or goes bad, it may need replacement. In such a case, it will not pull close. When that happens, the two ends do not connect with each other even when the current is directly run to it.
How do I know if my contactor coil is bad?
A simple way to test the coil is to make sure the A1 connection is receiving voltage using a volt meter or multimeter. If it is, then you can test your A1 to A2 coil connection and if the A2 connection is not receiving voltage (and A1 is), then you have a bad coil.
Can you clean a contactor?
0:000:41AC Contactor Cleaning Product - YouTubeYouTubeStart of suggested clipEnd of suggested clipSo this is some good stuff it's electronic cleaner and you can use it on contactors. And I used itMoreSo this is some good stuff it's electronic cleaner and you can use it on contactors. And I used it on my contactor. On my air conditioning unit outside because it was getting stuck on.
How can I bypass contactor?
0:461:38Contactor Relay - Purpose and Bypass Mode - YouTubeYouTubeStart of suggested clipEnd of suggested clipIf you need to put it in bypass mode you got to click it all the way to the left. So that's twoMoreIf you need to put it in bypass mode you got to click it all the way to the left. So that's two clicks. And that's all the way to the left that's gonna put it in bypass mode.
How do you test a contactor?
0:023:39How to properly test a contactor - YouTubeYouTubeStart of suggested clipEnd of suggested clipPut one lead on either side. And then push the middle that tells you that this side is good move toMorePut one lead on either side. And then push the middle that tells you that this side is good move to the other. Side. That other side would be bad. There's no continuity when you push it in.
How do you energize a contactor coil?
Contactors can have many sets of contacts or switches.Remove all electrical power to the L or line side of the contactor. ... Loosen and remove the wires from the T or terminal side of the contactor. ... Energize the contactor's coil by turning the control switch to the "on" position.More items...
What is 13 and 14 on a contactor?
Many contactor manufacturers use the designations A1 and A2 for the terminals that connect power to the magnetic coil. Likewise, many manufacturers use the designations 13 and 14 for the terminals of normally open auxiliary contacts. Auxiliary contacts are operated by the magnetic coil just like the main contacts.
What closes a contactor?
Coil or electromagnet The coil provides the driving force in a contactor that closes the contacts. It features a coil wound around an electromagnetic core and thus behaves like an electromagnet. The coil has two parts, a fixed one and a movable part with a spring connecting both parts.
Can a contactor fail closed?
No, they are not safe from failing closed. No switch is, mechanical or solid-state. Therefore, an E-STOP or other safety switch requires at least two overrated contacts that operate independently, so that one getting welded does not prevent the other from operating.
How do you test a contactor?
0:023:39How to properly test a contactor - YouTubeYouTubeStart of suggested clipEnd of suggested clipPut one lead on either side. And then push the middle that tells you that this side is good move toMorePut one lead on either side. And then push the middle that tells you that this side is good move to the other. Side. That other side would be bad. There's no continuity when you push it in.
How much resistance should a contactor coil have?
The meter should read from 10 to 100 ohms. If the meter does not, the coil is bad and must be replaced.
Why is my contactor not working?
Either the contactor 24-volt coil can go bad, the contacts could be burnt or pitted or insects and dirty might get in between the contacts and cause the contactor to not work.
Why is my low voltage transformer bad?
Most of the time when a low voltage transformer is bad or burnt out it is caused by a low voltage short in the low voltage wiring. Most of the time it is in the low voltage thermostat wires where animals, weedeaters, or a breakdown of the insulation in the wires from being exposed to sunlight over the years. Check the thermostat wires for breaks, worn insulation, and grounding out where the wires travel through the furnace, air handler, or air conditioner’s frame. I have seen many ground out shorts and burnt out transformers caused by animals and worn wire insulation where the wires travel through the frame of the furnace, air handler, air conditioner, or heat pump unit. We sell many low voltage transformers. Please click here if you would like to see the transformers that we sell.
Why does my AC shut down when the condensate pump is not working?
If a condensate pump is not working then sometimes (if connected) the safety switch will go off and cause the entire AC system to shut down so that you do not get water damage in your home. You could have a bad thermostat or bad, loose thermostat wiring. Make sure that all your thermostat wires are good and tight.
What happens if your refrigerant is low?
If your unit is low on refrigerant charge then the low-pressure switch might be open or tripped. If your unit is dirty, over-charged, has a restriction in the system, or has a slow or broken fan motor (might need a new capacitor) then the high-pressure switch might be open or tripped. You might have a bad contactor.
Can a 5 minute delay board go bad?
You could have a bad 5-minute delay board. We sell some of these delay timers on the following page: Please click here if you would like to see some of the delay timers we sell. There are different makes and model timers, but they can go bad and cause the air conditioner to no come on.
Can you have bad wiring on a thermostat?
Make sure that all your thermostat wires are good and tight. You could have bad wiring. I would recommend that you check all wiring to make sure that the insulation is good and there are no breaks in the wires.
Why Is Your AC Contactor Not Pulling In?
Surprisingly, it is something that can be avoided through periodic maintenance. Usually, the contactor malfunctions due to corroded contacts, coil failure, and contactor burnout.
What happens if you replace an AC contactor?
Brand differences are acceptable; what is not acceptable is the voltage difference. Replacing with an undersized contactor will put your AC unit under strain. As a result, the AC will either develop some significant problem or the contactor will keep getting fried.
What is a coil failure?
2. Coil Failure – In addition to the contact points, a contactor also has coils. Sometimes these coils fail altogether. At such times, the contactor develops a fault, and it may reflect in the form of failure to pull in.
What is the contactor on an air conditioner?
The contactor on the air conditioning unit is a switch that permits or stops power supply to the unit. It is a relay switch which directs electricity to the compressor of the air conditioner. When power is not needed, the contactor pulls the electrical contacts apart. It closes the contacts when something needs to be powered.
What to do if AC is not giving cool air?
If your AC is not giving cool air, ask the technician to check the contactor for any faults. Though the issue may not be with the contactor, it is necessary to rule it out as a possibility. If you are still not convinced, you can always ask for a second opinion. Tweet.
What is an AC contactor?
Your AC contactor is a small switch like device which has a very important job to perform. During the course of annual maintenance, you should ask the HVAC technician to take a look at it as well. If need be, ask them to clean its contacts to increase its productive life.
Why is it important to switch off the AC?
As a result, the AC will either develop some significant problem or the contactor will keep getting fried. Also, remember whenever you are working with electrical equipment, it is necessary to first switch off the power supply to it. This step is necessary to ensure that you do not get an electrical shock by mistake.
Why do contactors fail?
Reasons for contactor failure. Contactors have very high electrical life & normally don’t need so much maintenance. But it’s always better to have some knowledge about the failures of contactors. Therefore, special attention should be paid to the following points.
What causes contactor failure?
Wrong product selection is another cause of contactor failure. Contactor should be selected according to the type of load. The standard utilization categories define the current values which the contactor must be able to make or break. These values depend on: 1 The type of load being switched: squirrel cage or slip ring motor, resistors. 2 The conditions under which making or breaking takes place: motor stalled, starting or running, reversing, plugging.
Why does my contactor coil melt?
The control voltage of less than 85% during pick up may not be enough to safely close the contactor and can cause the coil to melt due to overheating. This because the coil is designed to withstand the inrush current for a limited time only. One common reason is when the coil supply is taken from the main supply where a high current is causing the voltage to drop. Too high continuous control voltage could also cause the coil to melt.
What happens when a contactor is closed?
On closing, the contactor makes the starting current, which is about 2.5 times the rated current of the motor. On opening, it must break the starting current, at a voltage less than or equal to the mains supply voltage. This category applies to squirrel cage motors with breaking during normal running of the motor.
What is breaking in a squirrel cage motor?
This category applies to squirrel cage motors with breaking during normal running of the motor. On closing, the contactor makes the starting current, which is about 5 to 7 times the rated current of the motor. On opening, it breaks the rated current drawn by the motor; at this point, the voltage at the contactor terminals is about 20 % of the mains supply voltage. Breaking is light. Application examples: all standard squirrel cage motors: lifts, escalators, conveyor belts, bucket elevators, compressors, pumps, mixers, air conditioning units, etc.
Why do contactors need to be protected?
Contactors need to be protected from condensation to keep the pole surfaces of the magnet free from corrosion. Besides, the contactor should be mounted inside an enclosure that protects the unit from dust and water. Unclean terminals increase connection resistance and, in this case, creates an overheat effect.
What is the voltage drop needed for contactors to open?
A voltage drop to less than 85 % of nominal voltage for 5 to 10 ms can be enough for the contactor to start opening. Also, other disturbances in the control voltage such as poor relay contacts or too small control transformer/power supply could be responsible for this problem. The result of these voltage problems can be increased contact wear and also lead to welding of main contacts.
Why does my contactor not close?
If the sealing circuit does not close, the cause could be from damaged or burnt contacts or any loose wiring connections in the contactor auxiliary contacts. Normally, the contactor holding should close when there is power.
How to check if contactor coil is open?
The very first thing that you should check is if the contactor coil can still move the contact assembly. If the answer is no, you may have an open circuit keeping the power from reaching and activating the coil. To be really certain, check the voltage at the coil terminals while it should be turned on. If the voltage is present, turn off the power by unplugging from the wall outlet or by shutting the circuit breaker down. Remove the wire from one of the coil's terminal, and setting your multimeter in a low ohm range, check across both terminals and if you read very high resistance or up to "∞", the coil is open and needs replacement.
Why does my overload relay trip?
One possible scenario could be that excessive heat generated by a motor has caused the overload relay to trip, thus cutting off the power to the relay. Another angle could be that the heat has prompted your motors to work a lot faster.
Why won't my circuit close?
If the reason why the sealing circuit does not close is because of any physical barrier that isn’t a safety feature such as dirt or dust, then simply remove it. You want to make sure that you unplug it or turn off the breaker to keep safe. You may want to keep your circuits secure from the elements to prevent anything else from getting caught in the sealing circuit.
Can sticky magnetic assembly cause problems?
A sticky magnetic assembly can actually cause technical problems. If this is the case, correct the problem with a non-conducting cleaner.
Can contactors jam?
But the system can jam from time to time. Although you should never try fixing problems that have something to do with electricity if you do not have the proper training and skills, troubleshooting a faulty contactor isn’t impossible. If you aren’t comfortable working with these components, hire a professional who can fix it for you.
