Help with understanding the electrical system

[Andy Burn]

Good evening,

Attached herewith are the photographs of the electrical system at my car wash. It is a 2 bay car wash and I cannot make head or tail of the system. The system works flawlessly for now but I would like to get a better understanding of the operations. I would be greatfull for any insights.

Regards

Andy

 

[MEP001]

In the top gray box with the hinged cover is the bay timer. I would highly recommend replacing those in the near future since they will only accumulate up to 15 coins worth of time. My customers routinely add 20 or more coins at once.

The black rectangular unit below them is the transformer. Since the wiring is in conduit, I can't tell whether they are 120V or 240V primary, but they step the voltage down to 24V AC. They most likely output two legs of 12V AC which combines to 24V of usable power, so you will only read 24V between "hot" and "common" with a voltmeter, but 12V to ground on either side.

The box with the clear cover holds your motor starter and thermal overload assembly, which I assume the two on the right are for the two bays you currently use, and the two on the left are older units that are no longer being used. The older ones have a standard 3-phase contactor with no thermal protection for the motor. In the lower right of that box is a relay that was/is used as a latching relay for the contactor, in which case you probably have start/stop buttons in the bay with a six-position switch. If it's been upgraded to an 8-position switch, those relays are not needed and probably aren't doing anything.