PIM-00004
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1
[Operation Manual]
9/61
DAIKIN INDUSTRIES, LTD.
[5.
Precautions for Use]
(1) To provide excellent energy-saving performance, this hydraulic unit provides the solenoid valve that switches the
dual pump operation between the combination mode and the single mode. If the machine operating point is close
to the solenoid valve switching point, the pump operation may become unstable. In this case, it is necessary to
adjust the flow rate setting (qH) or the pressure setting (PL) to a value below the solenoid valve switching point.
Furthermore, adjusting the dead zone provided around this switching point (see page 37 on p29,p30.) allows you
to stabilize operation.
(2) In this hydraulic unit, the motor pump unit is equipped with vibration suppressing rubber to prevent vibration
of the motor pump unit from being conveyed to the whole unit. For this purpose, the discharge pipe provides
a large degree of freedom. Therefore, when connecting the discharge pipe, be careful that the discharge pipe
will not touch the cover even if the pipe shakes with reaction force of the hose.
The piping to the unit should be connected with a hose, so that vibration of the motor pump unit will not be
conveyed to the machine.
(3) This hydraulic unit is equipped with an AC fan for cooling of hydraulic oil and motor.
To ensure spaces for air intake and exhaust, do not place an obstacle at 10 cm or shorter distance from the
fan motor air intake and exhaust planes.
(4) Frequently turning ON/OFF the power supply causes the controller service life to be remarkably shortened.
If you start and stop the hydraulic unit repeatedly by turning ON/OFF the power supply at intervals of 8
minutes or less, use the
“
start/stop
”
function using the start/stop signal. (See page 24)
When the hydraulic unit is started/stopped with the start/stop signal, the time interval to restart the unit after
stop command input should be at least 0.5 sec.
(5) This hydraulic unit incorporates a check valve that provides an orifice in the discharge line. If high
response is required for machine pressure release or other purpose, the machine must be provided with an
additional pressure release circuit.
If the load volume is large, you may hear a fluid flow sound from this orifice when the unit is stopped.
However, this phenomenon does not indicate abnormality.
(6)
This hydraulic unit uses an IPM motor, which generates counter-electromotive force during changeover
(regenerative operation). If the motor is frequently turned ON/OFF in the operating condition that easily
generate counter-electromotive force (a large load volume causes a large load reaction force accordingly), it
causes regenerative overload, resulting in unit stop.
(7) This hydraulic unit is equipped with a safety valve.
This safety valve has been set to a specified pressure before shipment. However, the set pressure of the
safety valve may decrease while the machine is repeatedly used for a long period, or due to contaminants in
the hydraulic oil.
If this unit is continuously used with the safety valve activated, it may output an alarm due to a temperature
rise and so on.
In this case, re-adjust the high pressure safety valve pressure setting according to
“
Attachment:
High-pressure Safety Valve Adjustment Procedure
”
(8) Continuous operations with maximum pressure is only allowable when operating flow rate is14.0L/min.
