Carbolite ELF 11/14B, Installation, Operation & Maintenance Instructions Manual

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ELF (B)
Thermocouple Replacement
Disconnect the furnace from the supply, and remove the furnace back panel.
Make a note of the thermocouple connections. The negative leg of the thermocouple is marked
blue. Compensating cable colour codings are:
negative: white
positive (type K): green
Disconnect the thermocouple from its terminal block and withdraw the thermocouple from its
sheath. It is advisable also to remove the sheath and shake out any broken pieces of thermocouple.
Fit the replacement thermocouple and reconnect, observing the colour coding.
Refit the back panel.
7.6 Element Replacement
See section 7.2 - wearing a face mask is recommended.
The element is supplied in the form of a complete inner chamber.
Disconnect the furnace from the supply and remove the furnace case back panel. Pull the chimney
out of the top of the furnace.
Make a note of the wiring connections (see also thermocouple colours, section 7.5.)
Disconnect the element power leads and the thermocouple connections. Remove the thermocouple
and support tube.
Using a socket spanner undo the four bolts that fasten the insulation box. These are located under
the insulation box in the two cross supports.
Remove the insulation box by carefully sliding it out through the back of the furnace case.
Take the new insulation box and carefully slide it into the back of the furnace up to the front face.
DO NOT support the insulation box by putting your hand inside it – the insulation is fragile.
Locate the insulation box fixing holes and replace the four bolts.
Refit the chimney, thermocouple support tube and thermocouple.
Remake all the thermocouple and element connections according to the notes made. If in doubt,
see the diagram below: on the 200-240V models there are two heating coils in series; on the 100-
120V models two in parallel.
Refit the back panel and run the furnace for 30 minutes at 800°C without interruption to ensure
complete burn-off of any organic binders. Smoke may be observed during this process, so it
should be carried out in a well-ventilated area.
Check that the furnace is controlling properly to rule out the possibility that previous element
failed because of a fault elsewhere in the control circuit.
Example Connections
L
L N
100-120V 200-240V = element
N
7.7
16 MF01