Allied Construction Products, LLC www.alliedcp.com
22
TM574173_HP4000_18feb
12.0 Technical Information – [cont'd]
12.2 Oil Pressure Check
IMPORTANT
The Allied work tool is designed to provide optimum
performance with reliable service at the oil flow and
pressure specified. Inattention to correct machine set
up may result in equipment damage, diminished
service life and poor efficiency.
Measure oil pressure whenever any the following
conditions occur
x
When first installed on a carrier
x
When repairs or modifications are made to the
machine’s hydraulic circuit.
x
When the machine operates other hydraulic work
tools.
x
When the Ho-Pac is removed from one machine
and attached to a different machine.
x
Check the pressure every 250 operating hours is
recommended.
12.2.1 How to Measure the Oil Pressure
CAUTION
Only qualified personnel, having knowledge of the
machine’s systems, proper test equipment and tools
should attempt testing and adjustments.
WARNING
Prevent accidental start. Engage
interlock, shut off engine and apply
parking brake. Follow all safety and
operating instructions provided by the
carrier manufacturer.
Certain tests, such as measuring the oil pressure,
can only be done while the Ho-Pac is operating.
x
Lower the work tool to the ground and stop the
carrier engine.
x
Relieve hydraulic pressure in attachment circuit.
x
Connect a pressure gauge [0-5000 PSI] to the
supply hose at the [IN] side of the work tool.
x
Use the provided form to record your results.
x
Start the carrier and position the work tool with
the tamping plate against the ground.
x
Adjust the engine's rpm to the normal operating
speed and set operating mode to "work tool".
x
The test can begin after the normal operating
temperature is reached.
x
Start the work tool and record the pressure
reading. It's normal for the pressure reading to
increase and decrease as the carrier applies
varying amounts of down pressure against the
springs.
x
Compare your results with the values listed in the
General Specifications Table.
x
When finished with the pressure-measuring test,
lower the work tool safely on the ground and stop
the engine. Relieve hydraulic pressure in
attachment circuit. Remove test gauge.
12.3 Definition of Hydraulic Terms
For the purposes of this manual, the following terms
are defined as:
Range
– Represented by two values 'V1 – V2', range
is the lowest-to-highest limit of a device that will allow
it to adequately respond. The term “minimum flow”
describes the least amount required that permits
continuous operation that’s both satisfactory and
efficient.
Hydraulic Flow
– A measure of the volume of oil
(values given in GPM / LPM) necessary for the safe
and efficient operation of the Allied work tool.
The motor is coupled directly to the eccentric mass.
The rotation speed of the motor must be kept inside a
narrow flow range. Too little flow will under-speed the
motor resulting in unsatisfactory performance.
Excessive flow (above the accepted flow rate) does
not improve compactor performance. Too much flow
not only results in overheating the oil, but also causes
the motor to over-speed which will add significantly
higher loads that contribute to early bearing failure.
IMPORTANT
Never use a relief valve as a means to reduce the
hydraulic oil flow. Oil by-passed over the relief
valve will cause significant heat generation.
