Carbolite PTC 12/20/150 - Manual (Page 13)

PTC
MF11 – 3.08 13
6.5 Thermocouple Replacement
Disconnect the furnace from the supply, and remove the furnace back panel (opposite the working
end). Make a note of the thermocouple positions; the 3mm upper thermocouple is the control
thermocouple; the 1.5mm entering in the centre is the reference.
Disconnect the thermocouple to be replaced from its terminal block and withdraw it.
Fit the replacement thermocouple, with the same length inside the furnace body as before,
observing the colour coding: negative = white; positive (type N) = green.
6.6 Element Replacement
See section 6.2- wearing a face mask is recommended.
This involves dismantling the outer case, disconnecting the electrical leads, and removing the
inner furnace chamber. Make a sketch of the layout inside the back panel before attempting this. It
is recommended that you contact Carbolite for advice before starting the operation.