Thomas & Betts LDAP 1200 - Manual (Page 35)

Form RZ-NA-I-LDAP, P/N 207733 (Rev 2), Page 35
Ignitor - Refer to FIGURE 22 and locate the ignitor. Disconnect the wire; remove
the screw and the ignitor. Clean the ignitor assembly with an emery cloth.
Spark gap must be maintained to 1/8". See FIGURE 25.
CAUTION: Due to high
voltage on the spark
wire and electrode, do
not touch when
energized. See Hazard
Levels, page 2.
FIGURE 25 - Ignitor
showing required
Spark Gap
measurement
1/8 inch
(3.2mm)
IMPORTANT: When re-assembling, the brown ground wire must remain attached
to the ignitor.
CAUTION: Due to high voltage on the spark wire and electrode,
do not touch when energized. See Hazard Levels, page 2.
Flame Sensor - Refer to FIGURE 22 and locate the flame sensor. Disconnect the
wire; remove the screw and the flame sensor. Clean with an emery cloth.
Flame Sensor
Ignitor
FIGURE 24 - DSI
Integrated Control
Module (Circuit
Board)
Only replaceable
part is a Type ATC
or ATO 3 amp fuse
(Color Code
Violet), P/N 201685
32. Ignition
System
DSI Integrated Control Module (circuit board) - See FIGURE 24. The module
monitors the operation of the heater including ignition. The only replaceable compo-
nent is the 3 amp Type ATC or ATO fuse. If the fuse is blown, the problem is most
likely an external overload. Correct the problem and replace the fuse.
Do not attempt to disassemble the control mod-
ule. However, each heating season check the
lead wires for insulation deterioration and good
connections. Size 400 has one control mod-
ule; Size 800 has two control modules; and Size
1200 has three control modules.
Proper operation of the direct spark ignition
system requires a minimum flame signal of 1.0
microamps as measured by a microampmeter.
For further information and check out proce-
dure on the direct spark ignition system, refer
to Paragraph 19 and the Troubleshooting Flow
Chart in Paragraph 43.
31. Burner
Orifice(s)
A burner orifice usually only needs to be replaced when installing a gas conversion
kit. If ordering replacement orifice(s) only, give BTUH content and specific gravity
of gas, as well as the model and serial number of the heater. When removing or
replacing a burner orifice, use two wrenches being careful not to damage the venturi
tube and/or the bracket.
2. Attach the Gas Train - Slide the gas train so that the orifice adapter is through
the bracket. Fasten the gas train to the bracket with the locking nut. Install the
gas orifice. Re-connect the wires to the gas valve. Re-connect the union(s)
inside of the control compartment.
3. Reconnect the gas supply at the union outside of the cabinet. Turn on the gas
supply and leak test the connections with leak detecting solution.
4. Close the access panel.
5. Turn on the electric. Check for proper operation.
33. Heat Section
Venter Motor
and Wheel
Remove dirt and grease from the motor casing, the venter housing, and the venter
wheel. Venter motor bearings are permanently lubricated. Follow these instructions
for replacement of the venter motor and wheel assembly. Keep all hardware re-
moved to be used in re-assembling and installing the replacement parts.