Power Soak MX-220-HTS Owner's/Service Manual - Manual (Page 30)

29
Component Operation and Checks
Watlow Heater Controller - Continued
The Watlow heat controller can be checked as follows:
1. Make sure the heat controller is wired as indicated above. Turn heater on/off
selector switch to "on".
2. If the heat controller is displaying any of the above error messages, take the
recommended action. If there is no display, go to step 4. If the heat controller is
displaying the actual and set temperature, go to step 7.
3. Program the heat controller. See programming on page 28. If the heat controller
cannot be programmed or programming does not correct the display, replace the
heat controller.
4. Check voltage across terminal 7 on the heat controller and L2 incoming power, and
terminal 6 on the heat controller and L2 incoming power. It should be 208v-230v.
If not, check the breaker, fuses, switch, liquid level control and wiring. Make the
necessary repair.
5. Check voltage across terminal 8 on the heat controller and L1 incoming power. It
should be 208v-230v. If not, check the breaker, fuses, transformer and wiring.
Make the necessary repair.
6. If the voltage checks ok in step 4 and 5 and the display is not lit, the heat controller
is defective.
7. Adjust the set temperature to 120 degrees as indicated above. If the set temperature
will not adjust, go to step 3.
8. Make sure actual temperature is less than 115 degrees. Check voltage across
terminal 5 on the heat controller and L2 incoming power. It should be 208v-230v.
If no voltage, the heat controller is defective. Note: The red indicator light at “2”
should also be on.
9. Adjust the set temperature to 114 degrees as indicated above.
10. Make sure the actual temperature is greater than 116 degrees.
11. There should be no voltage across terminal 5 on the heat controller and L2
incoming power. If there is 208v-230v, the heat controller is defective. Note: The
red indicator light at “2” should be off.