Bay power cycling

[chaz]

One of our s/s bays is having an issue when switching into or out of a high pressure function. This was intermittent…but now happens every time. Sometimes the bay will automatically reset (though time resets too)other times we need to power cycle the bay

We are using the Hamilton DAN timers originally installed by markvii in markvii doors.

We have switched the full door (timer,relay etc) to alternate bay…issue stays with bay

We disconnected the motor from pump and still had issue. Leading us to believe its electrical vs plumbing

We installed a brand new motor and still having same problem

Thoughts

 

[MEP001]

Might be a solenoid coil dead shorted. Disconnect them one at a time and test.

 

[Greg Pack]

All HP functions use a motor contactor. It doesn't happen often but I have had them go bad intermittently. If it happens on all HP functions I would look at the wiring going to the motor contactor.

Many cold rinse systems use a rinse solenoid. The wax has a wax solenoid and the soap has the soap solenoid. If you have it happen on just one HP function I would look at those

 

[Randy]

I had that very same problem not to long ago. It turned out to be a weak coil on the motor contactor. Another time we had that problem and that one turned out o be a loose wire. Get out the voltmeter and start checking the power to the motor contactor.

 

[cantbreak80]

Some Mark VII installations I’ve worked on use “undersized” control cables…20awg or even 22awg.

On long runs from the equipment room junction panel the voltage drop can be significant. The resulting low power to solenoids and motor starters can cause timers to power down, contactor chatter, etc.

Consider conductor length to and from the coin box…60+ feet. 24VAC out to the bay, through the switch, back to the equipment room…now you’re looking at 120+ feet between the transformer and the motor starter. If your system is powering a water supply solenoid in addition to the soap/wax solenoid, the motor starter coil power will “brown out” and then weird stuff happens.

One solution, (if all wire connections are sound, transformer VA output, motor starter and solenoid coils are within spec), is to install an isolation relay between the bay’s motor starter wire and the transformer.

• Connect the bay switch motor starter wire to the Relay's coil
• Connect the Relay’s NO contact to motor starter coil
• Connect the Relay’s Common contact to transformer Hot.

Since the isolation relay’s coil draws less power than the typical motor starter coil, this will provide full transformer voltage to the motor starter when high pressure soap, wax, rinse is selected.

 

[MEP001]

Some Mark VII installations I’ve worked on use “undersized” control cables…20awg or even 22awg.

I've seen this issue, but the only time it was ever a problem was when the incoming high voltage was 208V but the transformers were for 240V. My wash has the farthest bay with the wire run at about 100' and the low voltage wire is 22 gauge. No relays, everything has worked fine for 22 years.

 

[chaz]

THANKS All. issue was contactor/overload related. As noted in some reply’s….loose wire connections. Always the small silly things that drive us crazy.