PIM00587
EN-96
12.11
Safety Valve Adjustment Instructions
If any of the three conditions below is applicable, readjust the safety valve by referring to the [Safety Valve
Adjustment Instructions].
Usually, the safety valve is set so that it will not actuate even under use at the maximum operating pressure
setting (except during transition period where the hydraulic circuit is blocked due to a stop of the main
machine’s hydraulic actuator, for example).
1)
When the set pressure of the safety valve drops and it actuates even in the normal status due to
repeated operation over a protracted period or contaminants in the hydraulic oil.
[Judgment method]
●
When the oil temperature rise has become faster.
●
When, in the pressure holding state with the motor speed displayed, turning the safety valve
adjusting screw in the tightening direction lowers the motor speed.
2)
When, for reasons such as the restricted withstand pressure of the hoses used, it is desired to as far as
possible suppress surge pressures that greatly exceed the set value.
[Safety Valve Adjustment Instructions]
1.
Referring to the enlarged view of the safety valve on the next page, loosen the lock nut.
Lock nut: M10, width across flats of 14 mm
2.
In accordance with the guidance diagram for the length of the pressure adjusting screw,
bring the screw to about the length corresponding to the desired control pressure.
The tip of the adjusting screw has four faces, with width across flats of 7 mm.
3.
Turn on the power to the hydraulic unit, establish the setting mode by panel key
operation, and adjust the pressure setting to the desired pressure.
4.
Press the mode key
on the operation panel to switch the display mode to the monitor
mode.
5.
Press the setting keys
and
with the [n00] displayed to select [n05] (motor speed
indication) to display the current motor speed.
6.
Select [n05] (motor rotation speed indication) in the monitor mode by panel key
operation to display the current motor rotation speed.
7.
Adjust the pressure adjusting screw length in the longitudinal direction and find the
actuation start point shown in the figure below.
8.
Turn the pressure adjusting screw clockwise three fourths of a turn from the actuation
start point.
9.
Tighten the lock nut to complete the adjustment.
When tightening the lock nut, take care that the adjusting screw does not turn.
