Henkel KEEN KHT-900 - Manual (Page 6)

Corrective Maintenance
CHANGING HEATING ELEMENTS
1. Disconnect oven from power source.
2. Remove back cover and insulation.
3. Remove electrical leads from elements and inspect leads for damage. When removing or
installing leads on elements, use a backup wrench.
4. From inside of oven, remove element cover. Unscrew element brackets, and remove elements
from oven.
5.
Install and rewire elements, being sure all connections are tight and insulated.
CHANGING THE CONTROLLER
1. Disconnect from the power source and remove cover plate from control box.
2. Tag and remove leads from back of controller.
3. The controller is held in place by mounting brackets on either side of controller. From the rear,
loosen mounting bracket screws, remove mounting brackets and slide controller from control box.
4. To reinstall, slide controller into control box, attach mounting brackets and tighten set screws.
5. Replace electrical leads on controller terminals as per wiring diagram. Note: When attaching
thermocouple leads to controller, the negative lead wire has red insulation and the positive lead
wire has white insulation.
6. Check to be sure all electrical leads are on proper terminals and are secure. Replace control box
cover plate.
CHANGING THE CONTACTOR
1. Disconnect oven from power source.
2. Remove cover plate from control box.
3. Remove and tag electrical leads from contactor.
4. Unbolt and remove contactor from control box.
5. When replacing contactor, be sure it is of proper voltage and amperage.
6. Install new contactor and rewire as per wiring diagram. Check to be sure wiring is correct and
terminals are tight.
7. Replace cover plate on control box.
CALILBRATION INSTRUCTIONS
For calibration procedure refer to the “Controller User’s Manual”. When using a remote
thermometer to check oven temperature against controller display, be sure thermometer sensing probe is
placed next to controller thermocouple to achieve proper temperature reading.