In case you are having a problem with getting your motor to start this can be caused by a number of reasons. In this article, we will go through different techniques that will help you identify the problem that prevents your motor from starting. Besides we will offer some simple solutions too.
When the motor fails to start, there are a few things that you should keep into consideration so as to determine what might be the cause of the problem. In case it is a new installation and has never been started, then it is so important that you check the wiring diagram in order to determine and make sure that all the wires are properly connected. In case it is an older installation and has worked before, that means that it should be wired properly unless there were some changes that took place recently that might have caused any problem within the wiring. Here is a quick guide to troubleshooting the magnetic motor starter:
The visual inspections
First of all, inspect the terminals and cables to identify any signs of corrosion, burning, cable insulation cracking or any damage of any sort. In case you identify any visual evidence of any damage, switch off the power and have a licensed electrician review the components, installation as well as the wiring. If there is not any visual sign of the problem, then proceed to the following step.
The motor overload tripped
The most common motor problem and which can be easily fixed is that the motor overload might have tripped. The overload is designed in such a way that it protects the motor in case the current exceeds the maximum load amperage. This is just like resetting or checking the circuit breaker in your breaker box. In order to reset the overload, just push the red button that is found on the overload, or in case you have an external reset button, then press it. This is also an ideal time to ensure that the reset is configured in a manual mode.
In case the resetting of the overload did not solve the problem, then you can do a quick check so as to identify if the overload has failed. Make sure that you verify if the power is disconnected, the lockout the circuit in case there is a need for that. Then use an ohmmeter measure the continuity that is between the Normally Closed (NC) terminals on the overload. The exact resistance measurement is not important as you are trying to identify if there is continuity. If the Ohm meter indicates OPEN then the overload is damaged and has to be replaced.
The overload indicates continuity
In case the overload indicates continuity between the two NC terminals, then you will have to explore further. Record the information from the motor plate. It is critical that you know the voltage, phases as well as the maximum load amperage (FL) of your motor. With this kind of information, things can easily go smoothly.
Verify the overload configurations
Now you have to verify the overload configuration and make sure that it is set to maximum/full amperage from your motor’s nameplate based upon the supplied line power of the motor.
Verify the 3 phases
Once you have identified the needed input voltage, using a digital multimeter, verify that all the 3 phases of electrical potential are all working. In case it is a single-phase, make sure that the single-phase voltage is into existence. It is ideal to check this upon the cable that is moving within the contactor at terminals L1, L2, and L3. In case if there is a disconnect switch, check the incoming wires along with the disconnect. Measure between the legs L1, L2, and L3 to make sure that you have full voltage in accordance with the input line power of your motor.
Disconnecting the line power
In case you are missing one or more phases while the circuit consists of fuses, disconnect the line power and use your multimeter to measure for continuity over the fuses.
The blown fuse
In case one of the fuses is blown, then you will have to replace it. Sometimes the fuse holders might be corroded and this might prevent continuity. Therefor inspect to identify any corroded fuse holder and in case there is one, clean it using electrical contact cleaner together with a toothbrush.
In case you followed the above steps and yet nothing worked, then it might be the right time to call a licensed electrician for more help.