Common Contactor Problems and Troubleshooting Tips

Non-Performing Contactor can give all of us much grief with its difference between ‘up time’ vs. ‘down time’. Below are some typical contactor problems, as well as how to remedy the problems.
Common Problems Experienced with a Contactor
Contactor Fails to Close
this is a common problem, the contactor not closing, i.e., the electrical circuit not making, and the machine not starting. There are at least several things that can be wrong with the contactor causing this fault. Following are some of the more common problems.
Faulty Coil
Burned up or shorted contacts in the contactor may keep it from closing, i.e., being pulled closed.Fair test is with a multimeter.
Low Voltage
Not having enough control voltage can keep the contactor from closing. Get verifiable voltage reading at the coil as per manufacturer.
Contactor Mechanism Jammed
Dirt, dust, or some object inside the contactor will not let the mechanism travel the distance required. Clear the debris and clean.Contactor Contacts Welding or Burning
This usually causes, i.e., will lead to long-term damage, and we must be protected against the contacts of the contactor welding, or burning, together. The contacts are overheating, and not breaking the circuit.
Overloaded Circuit: Too much current going through, and the contacts in the contactor are overheating. Make sure that your circuit current is not more than the contactor rating.Wrong Application.Using the Contactor Wrong. You are trying to use the contactor on a type of load, or a type of application, for which it is not rated: a resistive load vs.an inductive load, or vice versa. Check your application against the contactor ratings.
Contactor Aging. The contacts themselves have suffered from the burning which takes place every time they open and close. Proper maintenance including a check of contacts in the contactor will eliminate this trouble.
Contactor Won’t Open
Sometimes a problem turns up—you find that your contactor won’t open, that is, that the circuit is closed when it shouldn’t be.
Coil Failure. If the coil is failed so that it will allow the contactor to stay closed with no current supplied to the control circuit it is a serious problem. A coil test will soon tell if that is the case.
Mechanical Blockage. Parts may be frozen, a moving contact and spring for instance, that can’t do its thing: too gummed up or sticky, that’s all. Proper lubrication and/or cleaning will take care of this.
Wiring Error. Wiring the contactor improperly is another reason for this failure as well as for failing to replace or put in. Follow the diagram that is furnished with it.
Contactor Making Loud Noise
If yours is noisily operating it may be for one or more of the following reasons:.
Loose Contacts.Contacts are loose fitting. If the contacts are a loose fit, they may cause arcing (a feature noisy when enforcing contacts to meet).Humming or buzzing noise.Tighten the loose connections and it will quiet itself.
Wrong voltage coil. If as a result the voltage is too high or too low, the contactor when trying to operate may hum or buzz. Check that the control voltage is correct.
Debris in the mechanism. Dirt or other things may be in the path of the operating mechanism in the contactor, keeping it from making contact and causing a buzz. Cleaning will silence this noisy contactor.
Contactor Short Cycling
If the contactor is cycling on itself or trying to cycle on and off, the following may often be the cause:
Control circuit. An unstable voltage or timer or relay shorting out may be causing the contactor to open and shut. Check the circuit control. Replace any bad part not working properly.
Bad temperature sensing. if the contactor is part of a temperature sense system, it may be that the sensing part(s) are bad. Make sure that all temperature sensors are working properly and if not, replace before using the contactor.
Overloaded or too small of a contactor. If the contactor is too small for the job it is possible that it could be overloaded and cycle as a result.Choose a contactor that is sufficiently large, and appropriately rated for the load that it will be switching on.
Contactor overheating
If the contactor overheating is at danger of getting out of control, you know it will not be long before this whole mess sputters and essential part will burn out. Here are some things which may be causing the fault:
Overcurrent load. Like welding or burning. When the current demand for the contactor is sufficiently high then it’s heat, at least inside. Ensure that the contactor is rated for the demanded load which it is switching.
Poor ventilation. Likewise if the unit is in a hot place, then the whole system will tend to heat up. Make sure that the area in which it is situated is not one which is going to keep all that tingy heat trapped inside.
Bad power supply. If you have a bad power supply, and get it to the contactor; or feeding it in a regulated way, and it will get hot inside the switching box. Make sure that it is getting a good regulated supply of voltage.
Troubleshooting tips
Maintenance. Check every now tip towards and if you notice any of the parts showing a tendency to be sarting, breaking part, or burnt contacts. Be sure to keep it as pristine as possible. But if your ordinary contactor is kept dirt free, and generally neat, it is going to last that much longer.
Don’t get the wrong one. At all. It is a well make in-that all is really, and commonplace cliched fact that your damn sure is that contactors are wrong size most of the time, and big as it is probably true also that most of the “goof -up” do make it to end customer, are seized as all contactor down the line. So it might be worth just a mention that a proper choice on the first try.
Test. And f it does not operate right, is oftener then not not the far simpler and more to the point are you start real testing contacts coils and control circuits, and also that test (around separately) all you could with not a volt meter; nor all electronic apparatus. Test in this manner. Change to new. If your trusty old is allege we say in about several month, well user if you yourself is=true, it will probably be a lot less expensive for you in the long run if you change to a new one instead, back it now and take the chance of catastrophic falling to of some other electric part next in line to that. Don’t spend unnecessary money with replacements such as that.