Carbolite EZS Series - Manual (Page 20)

E range
20 MF65-1.01 MF65-1.00
Before commencing any major repairs we recommend reference to the European Association
representing the High Temperature Insulation Wool industry (www.ecfia.eu)
We can provide further information on request. Alternatively our service division can quote for
any repairs to be carried out at your premises or ours.
5.3 Temperature Controller Replacement
301. This controller is fitted to the back of the control panel; in many models this can be separated
from the base by removal of two screws.
Before handling the controller: wear an anti-static wrist strap or otherwise avoid any possibility
of damage to the unit by static electricity.
Refer to the detailed instructions supplied with the replacement controller.
2132, 3216, 3508, etc. Ease apart the two lugs at the side; grip the instrument and withdraw it
from its sleeve; push in the replacement.
5.4 Solid-state Relay Replacement
Disconnect the furnace from the supply and remove the back panel from the base or control box.
Make a note of how the wires are connected to the solid state relay, and disconnect them.
Remove the solid state relay (SSR) from the base panel or 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.
Replace the removed panel.
5.5 Thermocouple Replacement
The coverings and guards which must be removed to gain access to the thermocouple depend on
the model, and possibly other options and fittings. For horizontal models it will be necessary to
separate the cylindrical body from the base, or remove some guards under the protruding ends of
the body. For the vertical models it will be necessary to dismount the furnace from its stand, and
remove the mesh terminal cover.
Disconnect the furnace from the supply, and separate the furnace body and/or remove covers and
guards as necessary.
Make a note of the thermocouple connections. Type N colour codings are:
negative positive (type N)
white pink
Disconnect the thermocouple from its terminal block.
Withdraw the thermocouple from the end of the furnace: ensure no broken bits remain.
If the thermocouple is supplied straight or coiled, bend it carefully to match the shape of the
original (working from the terminal end). Should the length differ from that of the original this
will usually not be important provided that the thermocouple tip is within a work tube diameter's
distance from the furnace centre. End zone thermocouple tips should be approximately two-thirds
of the way along the end element.
Insert the new thermocouple into position, restoring any removed porcelain spacers, and ensuring
correct polarity.
Re-assemble the furnace.
5.6 Element Replacement
Individual elements are not available for this model of furnace, if an element fails then a complete
element assembly is required. For details and fitting instructions contact Carbolite Engineering
Services, see back of this manual for contact information.