TM 9-4940-556-14&P
WARNING _ THESE PROCEDURES REQUIRE TESTS TO BE PERFORMED
WITH PROTECTIVE COVERS OPEN OR REMOVED.
THEY MUST BE
PERFORMED BY PERSONNEL TRAINED TO MAKE ELECTRICAL REPAIRS.
5.4.1.1 Secure cleaning gun and have personnel hold in the "ON" position.
Start unit following 3.3 with fuel on, place multi-meter across terminal
1 and 3. If 220 V is present, fuel solenoid is receiving power and is
either defective or stuck.
5.4.1.1.1 To determine if coil is defective, remove coil from valve and
If coil is working
insert screwdriver into coil. Turn burner switch ON.
screwdriver will be held in coil (no magnetic field present) and 5.4.1.1
indicated voltage to coil, coil is defective (or wire to coil is open).
5.4.1.2 If 220 V. is not indicated, one of the safety switches may be
malfunctioning.
5.4.1.3 WARNING - DO NOT OPERATE THE UNIT WITH ANY OF THE SAFETY SWITCHES/
CONTROLS BYPASSED--INJURY OR DEATH MAY RESULT. ONCE FAULT IS ISOLATED,
REPLACE SWITCH AND/OR RECTIFY CONDITION WHICH CAUSED SWITCH TO OPERATE.
5.4.1.4 In order to determine which safety switch is functioning/mal-
functioning follow the procedure below IN THE ORDER WRITTEN.
Tip in gun.
Water connected to unit/power connected to unit.
Main power ON.
Pump switch ON.
Burner switch ON.
Operating voltage (220 vac) should be obtained between the following terminal
If voltage is not obtained, check function of the component
strip locations.
listed at right. In order to quickly isolate problem, make voltage check
in the order listed.
Terminal
Pump Switch
S-2
1
-
2
PS-2
Pressure Switch
1
-
8
TC-1
Thermo Control
1
-
7
Burner Switch
S-3
1
-
4
FS-1
Flame Switch
1
-
5
PS-3
Air Differential
2
-
6
Turn MODE Switch to STEAM
S-4 Mode Switch
1-9
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