DRAFT
TM 5-4210-249-13&P-1
0003
Whenever the transducer signal is below 0.3 VDC or above 4.8 VDC, a sensor fault will be logged and SENSOR
will be displayed in MESSAGE CENTER. SENSOR will flash if the failure occurs while the pressure governor is
operating in psi mode. Once a failure is detected, the pressure governor can no longer maintain a pressure setting.
It will hold the current water pump engine RPM and only operate as a throttle. Once SENSOR is displayed in
MESSAGE CENTER, SENSOR will not clear until power to the pressure governor is reset. It is extremely
important that the cause for this message is investigated. The pressure governor cannot discharge pressure
properly unless the SENSOR signal is reliable and correct.
If the INC switch is held, the pressure governor will not allow a change greater than 80 psi (552 kPa) without
releasing the INC switch and pressing it again. This is only applicable when the discharge pressure is above 90 psi
(621 kPa).
If the discharge pressure drops below 30 psi (207 kPa) for any reason, the water pump engine speed will not be
increased. The pressure governor output voltage will reduce to the last known value where the pressure setpoint
was obtained. MESSAGE CENTER will display INTAKE during this low pressure condition. If the pressure
increases above 30 psi (207 kPa), OPERATOR will flash in MESSAGE CENTER and the pressure governor will
not increase output unless the operator presses the INC or PRESET switches. If pressure above 30 psi (207 kPa)
is not regained in 5 seconds, the pressure governor will return the water pump engine to idle and display
LOSUPPLY. The operator must make certain that the water supply is adequate and then reinstate the pressure
governor using the MODE, INC, and/or PRESET switches.
The pressure governor has a trim adjustment that can be set between 5% and 20% of maximum increase in a
pressure recovery attempt. MESSAGE CENTER will flash OPERATOR when this limit is reached and the RPM will
not increase further. The operator must take positive action to restore discharge pressure. If pressure is not
restored within 4 seconds, the pressure governor will reduce output to the last known output where pressure was
maintained. The operator must input a new setpoint with the INC, DEC, or PRESET switches. If the pressure rises
above the original setpoint and the pressure governor controls a decrease in water pump engine speed, the
pressure governor will return to normal operations and PSI MODE will be displayed in MESSAGE CENTER.
END OF WORK PACKAGE
0003-4
