Carbolite GP Series User Manual
Page 8
GP Ovens
8
MF17 3.07
5.5 Solid-state Relay Replacement
Remove the appropriate cover panel as given above. Make a note how the wires are connected to
the solid state relay, and disconnect them.
Remove the solid state relay from the aluminium plate.
Replace and reconnect the solid state relay ensuring that the heat-conducting thermal pad is
sandwiched between the relay and the base panel or aluminium plate. Alternatively a thin layer of
white, heat-conducting silicon paste may be applied between the new relay and the plate.
The new solid state relay contains a built-in MOV which protects it from short periods of excess
voltage. If the old relay had a separate disc-shaped "MOV" connected between the high voltage
terminals of the old relay, discard the old MOV.
Replace the removed panel.
5.6 Thermocouple Replacement
Remove the appropriate cover or control panel and the internal cover as given above.
Make a note of the thermocouple connections, and how the thermocouple is placed and fixed.
Colour codings are:
negative
positive (type K)
white
green
Disconnect the thermocouple from its controller terminals or terminal block.
Re-assemble with the new thermocouple observing the colour coding.
5.7 Element Replacement
Remove the appropriate cover or control panel and the internal cover as given above and locate the
element terminals.
Disconnect the wires from the element terminals. Remove any starlock washers - these may need
to be cut with wire cutters. Remove any clips holding the element inside the chamber, and
withdraw the element.
Reverse the procedure with the new element.
Run the oven at a low temperature and check that it is controlling properly, to find out whether the
element failure was caused by a fault in the control circuit.
5.8 Fuse Replacement
Remove the appropriate cover or control panel as given above.
Depending on the model and voltage, supply fuses and control circuit fuses may be mounted in
their own holders, or may be on a circuit board which contains an EMC filter. The fuses are
marked with their ratings.
Take care not to disconnect the wires leading from the EMC filter without first recording their
positions: they must be reconnected to the correct terminals.