Table of Contents
Advertisement
Service Manual
Operation
Speed sensors
Filtration options
Pressure override (POR) – 180 frame size only
Series 90 Pumps
An optional speed sensor can provide unit speed information. The sensor reads a magnetic ring on the
unit's cylinder block. See the corresponding section to locate, install, and adjust the speed sensor.
Series 90 pumps may have either suction or charge pressure filtration to filter the fluid entering the
circuit.
The suction filter is in the circuit between the reservoir and the inlet to the charge pump, as shown
below. The use of a filter contamination monitor is recommended.
Suction filtration
Hydraulic fluid reservoir
Charge pump
Adjustable
To low
charge pressure relief valve
loop and
To pump case
control
Suction filtration – option S
The suction filter is in the circuit between the reservoir and the inlet to the charge pump, as shown
below. The use of a filter contamination monitor is recommended.
Charge pressure filtration – option R, T, P, and L
The pressure filter can be mounted on the pump or remotely for ease of servicing. You will typically find a
100-125 µm mesh screen, in the reservoir or the charge inlet. This system requires a filter capable of
withstanding charge pressure (reference to atmosphere - add case pressure).
Charge pressure filtration
Screen
Hydraulic fluid reservoir
Charge pump
Filter
To low
pressure
side and
control
The Pressure OverRide valve (POR) modulates control pressure to maintain a pump displacement which
produces a system pressure level less than or equal to the POR setting. For unusually rapid load
application, the high pressure relief valve function of the multi-function valves is available to also limit
the pressure level.
The pressure override consists of a three-way normally open valve which operates in series with the
pump displacement control. Control supply pressure normally ports through the POR valve to the
displacement control valve. If the system demands a pressure above the override setting, the POR valve
520L0818 • Rev 0101 • August 2015
Manometer
Filter
P102 003E
Adjustable
charge pressure
relief valve
To pump case
P102 004E
13
Advertisement
Table of Contents
