Carbolite AX120 - Manual (Page 9)

Apex Series Ovens
MF42 1.10
9
5.5 Hydraulic Thermostat Replacement
Disconnect the oven from the supply and remove the side cover (see 5.3). Also remove the internal
element cover.
Pull off the knob from the thermostat. Remove the fixing screws. Disconnect any fixing clips or
screws inside the oven chamber, and ease out the capillary tube. Remove the thermostat.
Replace by reversal of the procedure.
5.6 Control Sensor Replacement
Disconnect the oven from the supply and remove the side cover (see 5.3). Also remove the internal
element cover.
Make a note of the connections to the temperature controller. Disconnect them.
Disconnect any fixing clips or screws inside the oven chamber, and remove the sensor.
Re-assemble with the new sensor. Take care not to damage the head by rough handling. In the case
of the platinum resistance thermometer the wires may be connected to the correct controller
terminals either way round.
Check that the oven is controlling properly, to ensure that the original fault was with the
temperature sensor.
5.7 Solid-state Relay Replacement
Remove the control 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 mounting surface.
Replace and reconnect the solid state relay ensuring that the heat-conducting thermal pad is
sandwiched between the relay and the mounting surface. Alternatively a thin layer of white, heat-
conducting silicon paste may be applied between the new relay and the plate.
Replace the removed panel.
5.8 Element Replacement
Disconnect the oven from the supply and remove the side cover (see 5.3). Also remove the internal
element cover. The element terminals are low down in the side compartment.
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.
5.9 Fuse Replacement
Disconnect the oven from the supply and remove the side cover (see 5.3).
Supply fuses and control circuit fuses are mounted on the EMC filter circuit board. The shorter
fuses are the control circuit fuses. 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.