Relief Valve Adjustment - Enerpac ZU4 Serie Instructions

5.8 Automatic Pump Operation With Pressure Switch
Option (Firmware 5.6 and later)
With the optional pressure switch installed, the electric motor
will automatically stop and re-start at a user defined setting. This
setting is entered via the pressure switch adjusting screw.
1. Connect unit to power, the LCD will show "OK".
2. Operate pump via section 5.1, 5.2 or 5.4.
3. When the "A" port pressure reaches the user defined limit,
the pressure switch opens, the motor is de-energized, the
LCD screen shows "AUTO ON" and the back light will flash
(the microprocessor is now aware that a pressure switch is
controlling the pump).
Warning: When the LCD backlight is flashing & "AUTO
ON" is displayed, the hydraulic system is under pressure
and the pump will automatically start the motor to
rebuild system pressure without input from the operator. Release
hydraulic pressure and disconnect electrical power to pump
before working on pump or hydraulic system.
4. When the "A" port pressure drops 115-550 psi, the pressure
switch closes and the motor is re-energized.
5. Pressing and releasing any button on the pendant (if
applicable) or shroud will stop this automatic cycle.
a. If the pressure switch is closed (motor energized) when
the button is pressed, "AUTO" is shown on the LCD.
b. If the pressure switch is open (motor de-energized) when
the button is pressed, "P Switch Open" is shown on the
LCD.
c. Pressing the motor activation button (Section 5.1, 5.2, or
5.4) reactivates the automatic pressure switch operation.
d. Pressing the pendant Down-Arrow (if applicable) will also
retract the cylinder.

5.9 Relief Valve Adjustment

Z-Class pumps are equipped with one user adjustable relief
valve (see Figure 10.) It can be adjusted as follows:
1. Install a gauge on the pump. If a unit is equipped with
optional pressure transducer:
Firmware 5.5 and earlier: verify "SET PRES" value is higher
than desired relief valve setting
Firmware 5.6 and later: verify AUTOMODE is off.
(See section 6.1C for more details).
2. Start the pump to allow the oil to warm.
3. Loosen the set screw locking nut.
4. Shift the control valve and build pressure in the system.
Using an Allen wrench, turn the set screw counter-clockwise
to decrease pressure and clockwise to increase pressure.
NOTE: To get an accurate setting, decrease the pressure to
a point below the final setting and then slowly increase the
pressure until it reaches the final setting.
5. Tighten the locking nut when the desired pressure is set.
6. Shift the control valve to the neutral position, allowing the
system pressure to return to 0 psi.
7. Recheck the final pressure setting by shifting the control
valve and pressurizing the system.
Locknut
6.0 LCD ELECTRICAL USE INSTRUCTIONS
The LCD version of the Z-class Pump is driven and operated by
a set of two boards: the Power Board (PB) and the Control Board
(CB), connected to each other by a flat cable.
On the PB are the terminals for the main power supply, the
motor power supply and all peripherals such as fan, valve
solenoids, pendant, pressure switch, pressure transducer, oil
temperature switch, and oil level switch. The PB also contains
the transformer, circuit breaker, rectifier and drivers.
CAUTION: The CB is an electrostatic sensitive device.
Special care has to be taken while handling this board
(i.e.: ESD wristbands).
6.1 LCD Function
Screen 1
Number
display 00000000
SET
0000.0
HOURS CYCLES
LOW MOTOR
VOLTAGE OVERLOAD
Besides the pendant, which is used to switch the motor on/off
and operate the valves, the CB with its four-button switches is
the main interface between the operator and the pump. With the
use of these four-button switches all functions and settings that
are described in the following can be activated.
CAUTION: Make sure that the plastic overlay, that
protects the LCD screen and the button switches, is not
broken or otherwise damaged. Never punch the button
switches with a sharp or pointed instrument, use fingertips only.
Clean the overlay regularly with a damp cloth; never use
aggressive or abrasive detergents.
A. Boot Sequence
Firmware 5.5 and earlier – When the pump is connected to electrical
power the LCD screen will show: "FIRMWARE x.x" for 2 seconds.
Firmware 5.6 and later – When the pump is connected to electrical
power the LCD screen will show: "FIRMWARE x.x" for 1 second,
then "Model xx" for 0.5 seconds, and then "motor UN/1P/3P" for
0.5 seconds.
Additional information may appear depending on pump model and
installed accessories. See Section 8.0 for more detailed information.
This is setup information about your pump that maybe needed for
service. The boot sequence is finished successfully when the text
display on the LCD screen shows "OK" (sequence takes
approximately 2 seconds).
5
Relief valve body (DO NOT TURN relief
valve body.)
Set screw
Figure 10
Text display
PSI MPa
BAR