26
l.
Reconnect furnace to power supply.
To Replace Furnace Chamber
a.
Disconnect furnace from power supply.
b.
Remove black knob holding furnace chamber to bracket
and remove furnace chamber.
c. Remove terminal plate on back of furnace chamber.
(Note placement and connection of wires.)
d. Disconnect thermocouple extension wires and power
cord from terminal block.
e. Remove back terminal plate on new furnace chamber.
f.
Insert power cord and thermocouple extension wires
through their proper holes in the bracket on the new fur-
nace chamber. (See Figure 2 for placement and connec-
tion of wires.)
g. Replace back terminal plate.
h. Insert screw on back terminal plate through bracket slot
and secure with knob.
i.
Reconnect furnace to power supply.
To Replace Type K (Chromel/Alumel) Ther-
mocouple (Manual Control Models)
a. Disconnect furnace from power supply.
b. Remove knob that holds furnace chamber to the bracket
and remove the furnace chamber.
c. Remove terminal plate on back of furnace chamber.
d. Remove two screws that secure the old thermocouple
and remove thermocouple by pulling straight back.
e. Insert the new thermocouple until tip extends approxi-
mately 1/4" into the heating chamber. Connect the lead
marked (+) on insulator of thermocouple to the terminal
across from yellow thermocouple extension wire, and
fasten the other thermocouple lead (-) to the remaining
terminal. (See Figure 2.)
(A polarity test of the lead wire is easily made with the
use of a magnet. On chromel/alumel thermocouples and
extension wires, the non-magnetic wire is positive (+ )
and the magnetic wire is negative (- ).
f.
Replace terminal plate.
g. Insert the screw on the terminal plate through the
mounting bracket and secure with knob.
h. Reconnect furnace to power supply.
M
AINTENANCE AND
S
ERVICING
