INFORMATION BULLETIN: MI95.74 03SEP09
Issue Date: August 31, 2009
In the event of an HWH computerized system control box, leveling or room control panel failure, the following procedure will allow manual pump operations using jumper wires to run the pump motor. This can be used to extend single-acting (spring return) jacks, to extend or retract double-acting jacks and to extend or retract room extensions, generator slides, etc. This can also be used for a diagnostic procedure.
WARNING: IT IS IMPORTANT TO OBSERVE ALL WARNINGS CONCERNING THE NORMAL OPERATION OF LEVELING SYSTEMS, ROOM EXTENSIONS, AND ALL OTHER HWH EQUIPMENT.
IMPORTANT: The pump cannot be running when attempting to retract single-acting (spring return) jacks.
WARNING: WHEN OPENING JACK SOLENOID VALVES FOR SINGLE-ACTING JACKS OR THE RETRACT SOLENOID VALVES FOR DOUBLE-ACTING JACKS, THE VEHICLE CAN DROP AND/OR MOVE FORWARD OR BACKWARD WITHOUT WARNING CAUSING INJURY OR DEATH. MAKE SURE PEOPLE AND OBJECTS ARE CLEAR OF THE VEHICLE BEFORE MANUALLY OPENING SOLENOID VALVES. MAKE SURE TRAILERS ARE PROPERLY SUPPORTED OR HITCHED TO A TOW VEHICLE BEFORE OPENING JACK SOLENOID VALVES.
JUMPER PROCEDURES
To run the pump motor with jumper wires, first, the master relay must be on. “Jumper A” will turn the master relay on. “Jumper A” can remain in place until the manual operation of the pump is finished. When “Jumper B” is applied, the pump motor will run. This jumper should not be connected unless a pump operation is required. Do not leave “Jumper B” connected for an extended period of time. Running the pump motor under load continuously for more than (3) three minutes* can overheat the pump motor causing damage to the motor. Remove both jumpers when the manual operation is complete.
*Pump run times will vary with the pump or motor size and pump operation. Larger pump motors can run longer.
