Power Soak MX-220-HTS Owner's/Service Manual - Manual (Page 29)

28
Component Operation and Checks
Heater Controller
The heat controller controls the wash tank temperature. On some models, this display is
not visible. If the display is visible, the Heat Control is made by either Watlow, or RKC.
They function similarly, but are visually different. If the display is not visible, the Heat
Control is made by RKC.
Wiring configuration
Wire Description Watlow RCK
Thermocouple red (-) Pin 1 Pin 9
Thermocouple white (+) Pin 2 Pin 8
L1 from heat switch (black) Pins 6 & 7 Pins 1 & 4
L2 from heat contactor (white) Pin 1 Pin 2
Signal to heat contactor (red) Pin 5 Pin 3
Watlow Heat Control
The red illuminated display will indicate the actual temperature on top and the set
temperature on the bottom. The set temperature is displayed when the “set” button is
pushed. To adjust the set temperature, push and hold the “set” button and push the “arrow
up” or “arrow down” button. The range of adjustment is typically 114
°F to 118°F. If the
water temperature falls below 110 °F, the display will flash “LO”. If the water temperature
rises above 120 °F, the display will flash “hI”. The red indicator light at “2” will light
when the controller is sending current to the heater contactor.
The Watlow heat controller will display the following error messages to assist in
troubleshooting:
Note: Excessive moisture can cause these error messages.
DISPLAY PROBABLE CAUSE RECOMMENDED ACTION
Er 2 Programming error See programming on page 28
Er 4 , Er 5 Microprocessor defective Replace heat controller
Er 6 , Er7 Thermocouple defective,
loose, broken wire
Check the thermocouple connections and
thermocouple. Replace as necessary.