Spa Power 750 safety relays on control board (two top on right) have 230v in but are not closing. what are the likely causes?
Safety relay coils will be part of a circuit designed to prevent something from happening until the conditions are safe, a pump perhaps, that will not be allowed to start unless there is sufficient water or a heater that should not operate without sufficient water.
The relays will not close until the circuit the coil is part of is complete. There will be the supply, the coil, various connections and possibly wiring and then a sensor or a switch or possibly two or even more switches and then a return path to a neutral, ground or negative depending on the circuit design and voltages. Relay contacts often control higher voltages than the coil uses so there might be 230 volts at the relay contacts but only 12 volts needed to energise the coil and close the contacts.
While there are relays designed to be energised by ac mains voltages, designers mostly choose low voltage dc and so there could be problems with a power supply.
When fault-finding on such an installation it is wise to first discover how the circuit is supposed to operate, ideally with the aid of a circuit diagram. This is especially important when relay coils are energised by the means of electronics instead of direct connection with sensors or control switches, which is not unusual.
Jun 27, 2016 |
Pool & Spa