Grindmaster AMERICAN METAL WARE 87710 - Manual (Page 12)

Action
1) Both “HI” and “XL” electrode circuits
open. Dual Level Control turns power on to
fill valve and keeps power off to thermostat.
2) “XL” electrode circuit closes. Power to
thermostat turned on. Power to fill valve
remains on.
3) “HI” electrode circuit closes. Dual Level
Control turns power off to fill valve and con-
tinues power to thermostat.
4) “HI” electrode circuit opens. “XL” circuit
stays closed. After a few seconds delay,
power to fill valve is turned on.
5) “XL” electrode circuit now opens. Power
to thermostat is turned off. Power to fill
valve remains on.
American Metal Ware 87710E Coffee Urn Page 13
Fill Solenoid
Valve
Thermostat
Thermostat
Thermostat
Thermostat
ON
OFF
ON
ON
OFF
ON
ON ON
Fill Solenoid
Valve
Fill Solenoid
Valve
Fill Solenoid
Valve
2. Description and Operation of Dual Level Control System (continued):
B.
3. Quick Service Check of Dual Level Control System:
1) All wire secure and properly connected.
2) Clean the electrodes. Lime (mineral scale) build-up can interfere with the
operation of any liquid level control system.
3) Check the common (ground) connection. A little looseness or dirt can cause
erratic operation.
Operation
Water Level
1) Below both electrodes
2) Rises to low electrode above
above heater coils
3) Rises to high electrode
4) Falls below high electrode only
5) Falls below low electrode.
(Same as condition no. 1)