CHAMPION USN72 - Manual (Page 61)

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Part 5: BASIC SERVICE
5.3 Component Repair and Replacement (Cont.)
5.3.8 Tank Heat Thermostat Adjustment and Replacement
Refer to Fig. 6.12, B , Part 6, Replacement Parts, for a detailed drawing of the thermostat
assembly. Each tank has a control thermostat mounted on its front in a stainless steel enclosure.
The thermostat capillary tubes run to either side of the tank. The thermostat sensor bulb enters
the tank and is secured inside the tank with a 1/2" locknut. The thermostats are adjusted by
turning a small adjustment screw mounted on the side of the device. The thermostats have an
operating range of 110-200 ° F. Place the machine in normal operation and monitor the associated
tank thermometer. Wash tank temperature should maintain a minimum of 150 ° F. Power rinse
tank temperature should maintain a minimum of 160 ° F.
Wash Tank Temperature = 150 ° F minimum
Power Rinse Tank Temperature = 160 ° F minimum
To adjust a thermostat: Turn the adjusting screw incrementally 1/8 to 1/4 of a turn clockwise.
Monitor the temperature thermometer after each adjustment until the desired temperature setting
is maintained during normal dishwasher operation.
To replace a thermostat: Drain the tanks and turn off all power to the dishwasher.
Have a helper hold the thermostat sensor bulb from the outside of the machine and remove
the 1/2" locknut from the interior of the tank. Pull the bulb and capillary back to the thermostat
junction box. Note the wire locations and disconnect the thermostat. Remove two retaining nuts
and remove the thermostat assembly. Install a new thermostat in reverse order. Be sure to apply
plumber's putty (Champion P/N 104889) to seal the thermostat bulb fitting in the tank. Return the
dishwasher to normal operating condition and adjust the thermostat as described above.
5.3.9 Final Rinse (Steam) Thermostat Adjustment and Replacement
Refer to Fig. 6.16, Part 6, Replacement Parts, for a detailed
drawing of the steam booster assembly. Note Items 10, 17 and
19. This shows the location of the final rinse control thermostat.
The thermostat has a range of 50-300 ° F. However, the operat-
ing range for final rinse application is 180-195 ° F. The normally
open contacts of the thermostat open on temperature rise.
The normally closed contacts close on temperature rise.
The thermostat's N.O. contacts are used for this application.
The final rinse thermostat controls operation of the steam
booster solenoid. It senses the outlet temperature of the final
rinse water leaving the booster and energizes or deenergizes the
steam solenoid as needed to maintain the final rinse temperature within 180-195 ° F.
Note Items 10, 17 and 15 in Fig. 6.16. This shows the location of the low temperature cutoff
thermostat, (TSK). The final rinse thermostat and the low temperature thermostat are identical.
The TSK has two applications. It may be used to immediately shut down the dishwasher in the
event the final rinse water temperature falls below 180 ° F., or it may be used to activate a chemi-
cal sanitizing system (supplied by others) which does not immediately shut down the dishwasher.
NOTE:
The operation of the low temperature cutoff thermostat is dependent on the final rinse
thermostat. Adjust the final rinse thermostat and the low temperature cutoff
thermostat together.