Troubleshooting Magnetic Contactor Problems
Electricity travels in circuits, and in the heart of those circuits are magnetic contactors designed to keep everything running smoothly. 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.
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 be having an open circuit. An open circuit stems from the inability of the contactor to energize. To be really certain, check the voltage of the coil terminals. Do this with a circuit that has been power down. Set your multimeter in a low ohm setting. The multimeter will record a high resistance. If this is the case, you should try replacing the contactor coil.
Holding Does Not Close
If the problem isn’t because of an open circuit, check the holding, also known as sealing circuit, instead. If the sealing circuit does not close, observe it for any inconsistencies in the control circuit and any loose wiring connections in the contactor auxiliary contacts. Normally, the contactor holding should close when there is power.
If the reason why the sealing circuit does not close is because of any physical barrier that isn’t a safety feature, then simply remove it. You want to make sure that you switch the circuits to low power to keep you from being electrocuted. You may want to keep your circuits secure from the elements to prevent anything else from getting caught in the sealing circuit.
Now check the magnetic coil’s voltage. If it fluctuates from time to time, the branch circuit may be experiencing voltage variations.
A sticky magnetic assembly can actually cause technical problems. If this is the case, correct the problem with a non-conducting cleaner.
Overload relays are actually vulnerable to intermittent operations. This problem occurs when the overload relays do not stay closed. Overload relays are often vulnerable to getting tripped. One possible scenario could be that a short circuit has damaged your breaker which in turn damaged your overload relay. Check the fuse of your breaker and see if it has been blown. If so, simply change the fuse and reset the breaker.
Another angle could be that the heat has prompted your motors to work a lot faster. Your overload relay will be able to notice this change and trip itself in an effort to protect the entire system from being further damaged especially the motor. In this case, you need to set up a system where the motor receives appropriate ventilation.