EF, AF
10
LF01
Switch the furnace ON and heat to 900° without interruption, then soak for 1 hour. Some smoke
may be observed during this process, which should be carried out in a well ventilated area.
Check that the furnace is controlling properly to rule out the possibility that the previous element
failed because of a fault in the control circuit.
5.8 Element Replacement – AF
See section 5.2- wearing a face mask is recommended.
The AF chamber is formed by winding resistance heating wire on to a refractory muffle former. In
the event of failure, the whole “wound muffle” assembly must be replaced.
Disconnect the furnace from the supply and remove the back panel and chimney.
See section 5.6 above that refers to the thermocouple colour coding and replacement instructions.
Make a note of the thermocouple connections. Unfasten the connections and remove the
thermocouple.
Disconnect the element tails and earth wire. Retain any insulation sleeves to refit later.
To remove the chamber box, slacken the 4 bolts on the underside, then slide the chamber box out
the back of the case. Be careful: the chamber is heavy.
Remove the top and back of the chamber box.
Remove the insulation boards and brick pieces as necessary to expose the muffle, making note of
their location for refitting. Remove the muffle.
If necessary, cut the tails of the new element to match those of the old.
Fit the new element into place.
Refit the insulation boards and brick pieces.
Refit the chamber top and back.
Refit the chamber box into the case and retighten the 4 bolts.
Refit and connect the thermocouple, element tails with insulation sleeves, and earth wire.
Refit the back panel reconnecting its earth wire, and refit the chimney.
Switch the furnace ON and heat to 900° without interruption, then soak for 1 hour. Some smoke
may be observed during this process, which should be carried out in a well ventilated area.
Check that the furnace is controlling properly to rule out the possibility that the previous element
failed because of a fault in the control circuit.
Summary of Contents for Lenton AF 11/6
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Page 15: ...EF AF LF01 15...
