Eaton Vickers EHH-AMP-702-D-10 Manual

Released 5/93 630
Set-Up Procedure
Proportional Power Plug
EHH-AMP-702-D/E-10
Vickers®
Valves

Introduction
Introduction
This set-up procedure describes the
adjustments on the Power Plug for
setting the dead-band, gain and ramp
rate on a non-feedback proportional
valve.
Proportional valves with over-lapped
spools have a range of spool travel
where there is no flow from the valve.
This range of spool motion is called
dead-band. Adjusting the power plug
allows the dead-band to be
electronically eliminated (dead-band
compensation) by making the spool
jump across the dead-band when a
small input signal is applied to the
power plug.
Gain +Output Flow
Input Voltage
The gain of the valve is the ratio of the
opening of the valve (or flow rate from it)
to the applied voltage input to the power
plug.
The ramp rate is the rate at which the
power plug allows the valve to open (or
close) when a step voltage input is
applied to the power plug. In many
applications this ramp would be used
to gradually accelerate or decelerate
an actuator.
Installation precautions to
eliminate leaks into the power
plug
SUse only cables with circular
cross-sections and diameter
between 5–10 mm (.2” - .4”)
SEnsure that sealing grommet is
present and installed correctly. It
must be forced over the outer jacket
of the cable.
SEnsure that all the gaskets are
present and properly seated.
SEnsure that the plastic cover seats
firmly and correctly on the center
body post.
Necessary Equipment
SEHH-AMP-702-D-10 or
EHH-AMP-702-E-10 power plug
SCompatible KDG series or KTG
series non-feedback type
proportional valve
SHydraulic power source and load
circuit
S24 volt DC power source
S10 volt DC power source
SDC voltmeter
S1000 ohm potentiometer
(multi-turn preferred)
SConnecting cables
Figure 1. Power plug set-up schematic
Connection of power plug
Referring to the schematic in Figure 1
and the power plug diagram in Figure 2,
connect the power supplies, voltmeter,
command potentiometer and valve
solenoid as shown.
ground
command
signal
input
LED
R1 – Ramp
adjustment.
Turn clockwise
to increase
ramp time.
R3 – Dead-
band
compensation
adjustment.
Turn clockwise
to reduce
deadband
compensation
current.
R2 – Gain adjustment.
Turn clockwise to
decrease gain.
Power input +24V
Figure 2. Power plug connections
EEaton Hydraulics, Incorporated, 2000
All rights reserved
+
–
–
+
+
–
–
+
1000W
command
pot.
volt
meter
Power
input
C
Signal input
R3: deadband
compensation
R1
Ramp R2 Gain
Power plug
Solenoid
Power
amp.
Modulator
Enable
24V DC
10V DC
Power
supplies

Adjustment Procedures
Figure 1 shows the set-up for one
solenoid. If the valve contains two
solenoids, the set-up and the following
procedure should be repeated.
CAUTION
Applying more than 10 volts at input C
may result in damage to the power plug.
Deadband adjustment
A. Turn potentiometer R3 on
the power plug fully
clockwise (no deadband
compensation) and R1
fully counter-clockwise
(maximum ramp rate).The
red LED will turn off (it
turns off to signify an “off”
condition valve, when
input voltage is less than
100 mV).
B. Adjust command
potentiometer until the
voltmeter reads 0.25 volts
at connection C.
C. Slowly adjust
potentiometer R3
counter-clockwise until
movement at the actuator
is detected.
Deadband compensation is set.
Gain adjustment
A. For many applications the
valve gain may simply be
set to a maximum by
turning potentiometer R2
fully clockwise.
For any other gain setting:
A.. Calculate the maximum
speed of the actuator.
Calculate 80% of this
maximum speed.
B.. Set command
potentiometer to provide 8
volts at C (8 volts is 80% of
maximum input voltage.
C.. Slowly adjust
potentiometer R2 until this
80% speed is observed at
the actuator.
Valve gain is set.
Repeat the deadband adjustment and
the gain adjustment steps at least once
more since adjusting one parameter
affects the setting of the other.
Ramp rate adjustment
A. For most applications:
Set R1 fully clockwise
(minimum ramp rate). Run
the actuator for different
increasing counter-
clockwise settings of the
potentiometer R1 until
slight hydraulic shocks in
the system are observed.
Back-off R1 clockwise until
the shocks just disappear.
Fastest shock-free ramp
rate is set.
B. For any other ramp rate:
Run the actuator for
different increasing CCW
settings of the
potentiometer R1, until the
desired velocity ramp is
observed at the actuator.
100% Deadband
compensation
0% fully CCW
Note that all adjustment lies within
40% of the potentiometer rotation.
~40%
Figure 3. Sensitivity of deadband
adjustment to potentiometer R3 (typical).
flow rate (or “gain”)
fully CCWfully CW
volt input
40%
Figure 4. Sensitivity of deadband
adjustment to potentiometer R3 (typical).
fully
CCW
fully
CW
Ramp time
Note that adjustment is very non-linear and
most adjustment lies within 40% of the
potentiometer rotation range for ramp-up
and 20% of the adjustment range for
ramp-down.
20% 40%
Figure 5. Sensitivity of deadband
adjustment to potentiometer R3 (typical).

Wiring Preparation
Attachmentscrew
Cover
GCenter body post gasket
GCover gasket
Power input
R1: Ramp adjustment. Turn clockwise
to increase ramp time.
R3: Deadband compensation
adjustment.
Turn clockwise to reduce deadband
compensation current
R2: Gain adjustment. Turn clockwise to
decrease gain.
Body
GMounting gasket
Cable grommet
Grommet cinch nut
LED
Command signal input
0V
Electronic module
GAll seals must be fitted correctly at plug
installation to provide protection to IP65
(IEC 529)
WARNING
Ensure cable clamp nut is adequately
tightened to secure the cable.
Do not connect or disconnect the
plug while power is on.
Do not mount or dismount the plug
when power is on.
3 x 0,5–1,0 mm2
(20AWG-18AWG)
O5 –10
(0.197–0.394 dia.)
Use single cable
with round outer
jacket such as:
Alpha #1952/3
Belden #8770
Stretch cable
grommet
over outer
jacket
5 (0.2)
Figure 6. Power plug exploded view
Vickers, Incorporated
A TRINOVA Company
5445 Corporate Drive
Troy, MI 48007–0302
Phone: [phone]
Fax: [phone]
630 Rel 5/93 Printed in U.S.A.