Lincoln 1400 Series Service Manual page 28

THE FOLLOWING ITEMS ARE USED IN THE MODEL 1456, 1457, 1474, 1475, 1476 IMPINGER OVENS
AIR PRESSURE SWITCHES - REPLACEMENT AND ADJUSTMENT
1. Remove control panel top.
2. Disconnect wires from switch making note of wire number and location for reinstallation.
3. Remove air tube from switch assembly.
4. Remove switch from wire hanger.
5. Install new switch in reverse order, make sure air tube is not blocked or miss-aligned. Adjust as needed.
To adjust the air pressure switch, remove snap on cover on the side of the switch to
expose adjusting screw. To increase sensitivity, turn screw counter clockwise; to
decrease sensitivity, turn screw clockwise. Check for proper line voltage switching from
N.C. to N.O. as the air pressure switch closes.
GAS VALVE - REPLACEMENT AND ADJUSTMENTS
1. Remove control panel top and front cover.
2. Disconnect the gas piping from the back of the unit.
3. Remove the four(4) screws from the incoming nipple mounting bracket.
4. Remove incoming nipple.
5. Disconnect two (2) plugs, (1) 3 prong and (1) 4 prong - Note location.
6. Disconnect pipe union just above gas valve and remove assembly.
7. Reassemble in reverse order (check all pipe fittings for leaks). After assembled, check
for proper adjustment of gas pressure switch, 8.8 on dial for natural gas, 23 for L.P. Gas and
4.5 for town gas.
8. Check and adjust manifold pressure. remove pressure tap located in gas piping above the
gas valve prior to the burner orifice and install manometer. Adjustment screw is located on the
front of the valve, remove plastic cap and adjust as needed: 3.5" WC for Natural Gas and 10" WC for L.P.
9. Check gas filter by removing cover plate (located on either side of valve). Remove four (4) screws and slide filter out
of valve housing and inspect. Reassemble in reverse order and check
10. for leaks around the cover.
SIDE VIEW
FILTER
COVER
PLATE
28
TOP VIEW
PRESSURE
CONTROLLER
ADJUSTMENT
-
FILTER
COVER
PLATE
3
2
gnd
Impinger I – 1400 Series Advantage Service Manual - Dom & Int'l
OUTPUT
MANIFOLD
PRESSURE
ADJUSTMENT
+
gnd ELECTRICAL
CONNECTOR
1 2
3
ELECTRICAL
CONNECTOR