9.0 Repairs and Replacements
9.4
Solid-state Relay Replacement
Disconnect the product from the power supply and remove the
appropriate cover as given above.
1. Make a note of the wire connections to the solid state relay, then disconnect them.
2. Remove the solid state relay from the base panel or aluminium plate.
3. Replace and reconnect the solid state relay ensuring that the bottom of it has good
thermal contact with the base panel or aluminium plate.
4. Replace the access panel.
9.5
Thermocouple Replacement
For vertical models it may be necessary to dismount the furnace from its stand and
remove the terminal cover.
Disconnect the product from the power supply. Remove terminal cover to gain
access to the thermocouple connections. Make a note of the thermocouple
connections.
Thermocouple cable colour codings are:
thermocouple leg
colour
positive (type N)
pink
negative
white
Disconnect the thermocouple from its terminal block.
Carefully withdraw the thermocouple from the product and remove any broken bits of
thermocouple.
Bend the new thermocouple carefully to match the shape of the original (working from
the terminal end). Should the length differ from that of the original this is usually not
important provided that the thermocouple tip is within a work tube diameter's distance
from the furnace centre.
Insert the new thermocouple into position, restoring any removed porcelain spacers and
ensuring correct polarity.
Re-assemble the furnace.
9.6
Fuse Replacement
Fuses are marked on the wiring diagram with type codes, e.g. F1, F2. For more
information on fuses refer to section 12.0.
Depending on model and voltage, the different fuse types may or may not be fitted.
If any fuse has failed, it is advisable for an electrician to check the internal circuits.
Replace any failed fuses with the correct type. For safety reasons do not fit larger
capacity fuses without first consulting Carbolite Gero.
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