TESTING- Solenoids, contactors or relays

Testing Solenoid Coils

1. First do a quick check with a screw driver to center of the coil (solenoid valve only) and see if there is magnetism or at least some power to it.
2. First look at the coil, usually there is a tag or the voltage is stamped on it. Check to make sure your getting power. If yes continue below tests.
3. Check both directly at coil and also check connections from terminals in electrical cabinet to include cable incase there is a short or open.
4. Set it to measure Ohms Resistance.
   
5. Each coil contains 2 wires. One wire will be shared with the coil at the other end if it is a double solenoid control valve. Disconnect both wires from terminal at solenoid or in electrical cabinet.
   
6. Touch one probe to each terminal.
7. The meter usually read around 80-200ohms. If its less then 20 ohms coil is most likely shorted. If its above 500 ohms it is most likely open and should be replaced. If possible look for another solenoid to compare readings with.
8. If coil ohm resistance looks ok and correct voltage is at coil. Valve/spool must be stuck or broken. Try cleaning it out with air.
   

Testing Ice cube relay coils and contactors

1. First look at the relay or contactor to find out what voltage it takes to pull in the coil. Otherwise check prints. Check to make sure your getting power to it and the voltage is correct. If yes continue below tests the coil of the relay or contactor is probably open.
2. Set meter to measure Ohms.
   
3. Each coil contains two terminals A1(positive)and A2 (negative or 0v).
4. Detach wires from A1 and A2 Touch one probe to each terminal.
5. The meter usually read around 80-200ohms. If its less then 20 ohms coil is most likely shorted. If its above 500 ohms it is most likely open and should be replaced. If possible look for another solenoid to compare readings with.
6. If coil ohm resistance looks ok and correct voltage is at coil. Replace the coil or contact.
7. If voltage is low check A1 to the common(0v) on a main terminal strip. If this is ok you have a loose connection or bad wire on the common side.

Note: Some contactor coils generally larger 230V will often show an open when testing with a meter and should be checked with the power applied to determine if the power is present. Which incase should be pulling in contactor