Service manual

Replacing a Switch
Or Pyrometer
(Manual Kilns Only)
1 UNPLUG kiln.
2 Remove the screws on
the sides of the switch
box that hold it to the
kiln. Gently lift the box away from the kiln.
3 Switch: Pull off the switch knob with fingertips.
Hold the new switch at the side of the switch box in
the same position as the
defective switch, aligned in
the same direction. Re
-
move and transfer one wire
at a time from the old
switch to the new one.
Make sure each connec
-
tion is tight. Replace
push-on connectors and wires damaged by heat. If
wire connectors do not fit snugly on terminals,
gently squeeze the end of the terminal with pliers.
(See photo, page 17.)
Remove the single nut from the front of the defec-
tive switch. Remove the switch and put the new one
in place making sure it is right side up. Reinstall the
shaft nut checking to be sure it is not backwards.
Tighten the switch so that it will not turn during op-
eration.
Pyrometer: Remove the thermocouple wires from
the pyrometer and the four nuts holding the pyrom-
eter in place. Install the new pyrometer. The red
wire attaches to the negative
terminal, the yellow to the pos
-
itive.
3 Check to see that wires are not
touching kiln case or the ele
-
ment connectors. Wires
touching element connectors
or the kiln case will burn out.
Move switch box into place and reinstall switch box
screws.
Replacing the
Temperature Controller
(Digital Kilns Only)
1 UNPLUG kiln.
2 Remove the 4 corner screws holding the controller
faceplate to the switch box. Carefully lift out face
-
plate.
3 Disconnect all the wires from the back of the board.
You will find two plugs and two single wires.
4 Connect the wires to the new board. Reinstall face
-
plate.
Reseating a
Bulging Element
To push a bulging element back into the groove, first heat
the element. Once an element has been fired, it becomes
brittle and will break if it is bent while cold. Follow this pro
-
cedure to heat the element:
1 UNPLUG the kiln. Use a small propane torch
(available at a building supply store) to heat the
bulging element. Stop heating when the element
glows dull red.
2 With a pair of long nosed pliers, shrink the bulging
portion of the element by pressing the individual
turns in the coils together slightly. Take a little from
each turn so that no two turns will be pressed tightly
enough to touch.
3 As the element shrinks,
work it back toward the
groove and into place.
Work rapidly, and at the
first sign of stiffness in the
coils, stop bending and re
-
heat the element. The ele
-
ments do not have to be red
to be bent safely, as the
stiffening can be felt
through the pliers.
4 To lengthen the element to
fit into the corners, reverse
the above procedure and
expand the distance be
-
tween coils by using
snap-ring pliers. Use cau
-
tion, as your warranty cov
-
ers elements that fail only in service under normal
use and not from being broken while cold.
5 When you have the coils positioned above the
dropped recess in the grooves, press the element
into the groove with a blunt kitchen knife.
Note: Do not use a plastic object, such as a comb, to
press the hot element into the groove. Melted plas
-
tic ruins elements.
18/
These two photos show how
to shorten and lengthen an el
-
ement. Use needle nose pliers
to shorten; snap-ring pliers to
lengthen.