TM 10-4610-310-14
UNIT MAINTENANCE
LIGHTWEIGHT WATER PURIFIER
TROUBLESHOOTING PROCEDURES
HIGH-PRESSURE PUMP MODULE
PRESSURE SWITCH, HIGH OR LOW
GENERAL
This work package lists the common malfunctions that you may find during the operation or maintenance of the
Lightweight Water Purifier (LWP) for either the high-pressure switch or low-pressure switch on the high-pressure
pump module. You should perform the tests/inspections and corrective action in the order listed.
The high-pressure switch is set at 1250 psi and the low-pressure switch is set at 160. When the pressure
exceeds 1250psi, the HP switch will shut down the diesel engine. When the pressure drops below 160 psi, the
hour meter, antiscalant pump and the Hypochlorite pump are turned off.
This manual cannot list all malfunctions that may occur, nor all tests or inspections and corrective actions. If a
malfunction is not listed or is not corrected by listed corrective actions, notify your supervisor.
WARNING
When checking for voltage on an energized component, extreme care must be taken. Only qualified and
authorized electrician should maintain, troubleshoot, and operate energized equipment. Injury or death to
personnel may result.
MALFUNCTION
TEST/INSPECTION
CORRECTIVE ACTION
1. engine shuts down at higher
Recalibrate the high-pressure
See WP 0096 00.
or lower than 1250 psi. (HP
switch setting.
switch)
If present, proceed to the next step. If
2. engine does not shut down.
not, Measure the voltage across pins A
(HP switch)
Measure the voltage across wire
and B at the control module (J7). (120
2 and 3 at the HP junction
VAC) If present, replace HP module
box. (120 VAC)
cable. If not troubleshoot control
module.
Ensure that the RO reject valve
If not present, check for continuities on
is opened. With power on,
wires 2 between HP junction box and
Measure the voltage across
HP switch, repair or replace damaged
wire 2 and ground at the high
wire. Otherwise, proceed to the next
pressure switch. (120 VAC)
step.
If not present, replace high-pressure
With power on, measure the
switch. Otherwise, proceed to the next
voltage across wire 6 and
step.
ground at the high pressure
switch. (120 VAC)
If not present, check for continuities on
With power on, measure the
wires 6 between HP junction box and
voltage across wire 6 and 3
HP switch Repair or replace damaged
at the HP junction box. (120
wire. Otherwise, proceed to the next
VAC)
step.
Test for continuity between wire
If not present, replace HP module cable.
6 and pin D at the other end
Otherwise, troubleshoot control module.
of the HP module cable
3. Low-pressure switch fails to
shut down the hour meter,
Recalibrate the low-pressure
See WP 0096 00.
antiscalant and hypochlorite
switch setting.
pumps at lower than 160 psi.
0067 00-1
