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Dishwasher fill question
Greetings everyone, I have a Hobart dish machine model CRS86A that has a pre-wash tank. This tank is filled via the wash and rinse tanks when filling. It also has a fill valve that was leaking by which I repaired. My predecessor had disconnected the wiring to the solenoid (don’t know why). Did not have voltage to wiring when filling. When tanks were almost full, valve opened and continued to run for 5 min. running water down the drain until I turned unit off. (now I know why he had it disconnected) I have 2 float probes in this tank. 1 to shut of main fill when tank is full (which works) Another which I do’nt know what is for. And a pig tail type probe. The fill valve is operated by one of these 2 latter controls. When is this valve suppose to open and is it on temp. rise or fall? Thank you in advance on any help u provide
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1 Reply
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The wash & rinse tanks each have three float switches (if I remember correctly).
The top and middle float switches are identical. They’re BOTH two wire, normally closed switches. TOGETHER – their task is simply to maintain a sufficient water level in the tanks:
When the machine is empty and turned on, since they’re both closed, they energize a fill control relay which powers the fill solenoid(s). Although the middle float switch will obviously satisfy (and open) first, fill continues until the top float switch opens, thereby de-energizing the fill control relay. If water drops below the top float (thus closing it), but the level remains above the middle float (which is still open), the fill circuit remains idle. If water level drops below the middle float, it closes…and if it stays closed for more than five seconds (due to a time delay relay), then the time delay relay allows the fill control relay to energize. It will remain energized until the top float switch is once again satisfied.The bottom float is a switch AND a temperature probe, so it has two sets of wires (four wire):
That switch is normally openand has nothing to do with controlling the fill cycle. It simply initiates heat (be it gas, electric or steam) when water level is above the heating medium. The probe part of it is connected to a solid-state thermostat to control heating temperature of the water.The prewash tank’s two float switches are identical to the first two I’ve explained above:
The prewash circuit operates in parallel and tied in directly to the rinse tank float circuit to energize the time delay relay and fill control relay. There is no four-wire float in that tank since it’s not heated.
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