electrical question

[angryk]

Hello all. Even though my question does not involve any refrigeration equipment(There were refrigerators in the area, LOL), I am going to ask it anyway. It involves a steamer, for those of you who would like to know. The unit has a 24 volt solenoid valve that is not oprating. I ohmed out the solenoid and it checked out fine. Next I checked for voltage at the two wires to the solenoid. I picked up 25 volts across the two wires, but it will not energize the solenoid. I checked the solenoid with another power supply and it energized. I picked up voltage that was backfeeding before on other pieces of equipment, but never across the two terminals like is happening here. Usually from a terminal to ground. The power supply to the solenoid coil comes from an electronic board. No trouble codes or anything to hint at a malfunction. The unit works fine except this one solenoid which is not essential to its operation. Its purpose is to spray cool water into the drain to cool down the steam in the drain. Now that i think about it, I would imagine that if reconnected the wires and checked the voltage at the solenoid terminals, I would have none. Any ideas or comments on how I am picking up voltage between the two wires(and from one wire to ground, if anybody is wondering). It is really throwing me for a loop.

[angryk]

By the way, I condemned the board, even though I hate doing something when I am not entirely sure, but it seems to be my only choice.

[frank]

Hi Angryk

When you check for voltage you really have to do the check under load conditions. It may be that the voltage drops when the valve is energised therefore it cannot sustain the currant draw. Sounds very much like you have a faulty supply if the valve coil checks out ok


Frank

[angryk]

Hi Frank, thanks for the reply. I came to the same conclusion. The manufacturer tells me if it's not the solenoid, it's the board. From now on I am going to check for voltage under load, like you said, and save myself some embarasment.

[750 Valve]

Dodgey solid state relay on board? Have had similar readings on refrig case controls with solid state relay. Usually a solid state, as opposed to a current coil relay if a fast pulsing action required from valve.