Model 30000-S DHPU Manual
Rev. 0
JRK
17SEP12
Page 17
Emergency Stop Manual Shutdown
The unit has an emergency stop manual shutdown. Pulling and holding the handle, detailed
in the control panel photo, closes off the air intake to shut the engine down. Use this method
for emergency situations, not for routine operation. The engine should not be started again
until the area is declared safe for operation. The proper way to stop the unit is detailed in
the shut down section.
Fan Belt Break
If the fan belt breaks on the engine, the ruptured piece will trip a spring loaded bar that is
connected to the engine fuel injection pump control rod. Once tripped, the engine
immediately stops. This safety feature prevents the motor from overheating if the cooling
fan stops turning due to a belt break. See the Hydro-Throttle figure for the location of the
spring loaded bar.
Low Oil Pressure/High Oil Temperature Shutdown
The power unit is set to shut down if the oil pressure gets too low or if the oil temperature
gets too high. The Sentinel diesel protection system valve controls the when the engine is
shut down by cutting off the fuel. The location of this valve is seen in the Hydro-Throttle
figure. For more information, refer to the cut sheet in the engine section of the manual.
System Relief Valve
The system hydraulic pressure relief valve (RV-1 on the hydraulic schematic) is shown in the
following photo. This valve limits the maximum pressure from the power unit hydraulic
pump. It is factory set to relieve at 3000 PSI. To adjust the valve setting, loosen the jam nut
at the bottom of the valve stem. Turn the knob clockwise to increase the pressure setting
and counter clockwise to reduce the setting. Lock the jam nut back down after adjusting the
valve setting. To develop pressure in the circuit, either the tong needs to grip and stall on a
tool joint or the pressure line can be removed at the quick disconnect (while the unit is off).
DO NOT SET THE RELIEF VALVE HIGHER THAN THE POWER UNIT DESIGN PRESSURE
OR THE ALLOWABLE PRESSURE TO THE COMPONENTS.
Components
The following sections will explain the major components in the hydraulic system to help the
user familiarize themselves with the operation of the power unit. Examine the hydraulic
schematic in conjunction with the text below. The assembly drawings will also help identify
the physical locations of the components.
Hydraulic Pump
In the schematic, the hydraulic pump is referenced by HP-1. The pump is a fixed
displacement gear pump with two sections, which is connected to the motor (DM-1) using a
pump adapter (PA-1) and pump coupling (PC-1). The pump has an integral high/low circuit
as previously discussed. The valve is factory set at 1500 PSI (103 bar) and should not be
