46
Troubleshooting
– Series 2 Variable Displacement Pump
Pressure Readings
The pressures given in this manual are gauge pressures or delta pressures.
A pressure gauge reads zero when connected to atmospheric pressure.
Any reading above or below this zero point is referred to as gauge pressure (PSI).
Delta pressure is the difference of two gauge pressures in a hydraulic circuit.
For example:
Charge pressure reading of 340 PSI [ 23,4 bar ]
Minus Case pressure reading of 20 PSI [ 1,5 bar ]
Equals Differential pressure of 360 D PSI [ 23,4 bar ]
Typical hydrostatic circuits usually include inlet pressure, case pressure, low
or charge pressure and system or high pressure. These pressures will vary
per each individual application and operating conditions.
Nominal Operating Pressures
(At Normal Operating Temperature)
Inlet Vacuum: Should not exceed 10 in. Hg. [ 254 mm Hg ]
(inches of mercury) for an extended period of time
Case pressure: Should not exceed 40 PSI [ 2,8 bar ]
for an extended period of time
Charge Pressure:* Neutral 340 PSI [ 23,4 bar ]
Forward or Reverse 280 PSI [19,3 bar ]
*Charge Pressure Relief valves are factory preset to their nominal setting with a
2 GPM [ 7,6 l/min ] flow rate. The original valve pressure will increase approximately
3 PSI [ ,21 bar ] per 1 GPM [ 3,8 l/min ] additional flow over the valve.
The charge pressures given above are typical. Higher charge pressures may be
set at the factory for your particular application.
