Valve amplifier for proportional pressure valves Type VT

Valve amplifier for proportional pressure valves Type VT
Valve amplifier for proportional pressure valves
RE 30214 Edition: 2013-04
Replaces: 06.05
Type VT-MRMA1-1
▶ Component series 1X
▶ Analog, modular design
▶ Suitable for controlling a direct current motor-operated
pressure reducing valve with electric position feedback
of the type (Z)DRS, size 6, component series 1X
H7125
Features
Contents
▶ Snap-in module housing with detachable plug-in
screw connectors
▶ Configurable actual pressure value input
▶ Ramp times (up and down) can be separately adjusted
▶ Linearization
▶ Electronic limit stops for the actuator
▶ Position controller with "position command value
reached" detection
▶ Enable input
▶ "Ready for operation" output
▶ "Position command value reached" output
▶ Configurable actual pressure value input
▶ Integrated pressure switch function with adjustable
switching thresholds
▶ Switchable measuring socket
▶ Fault recognition (cable breaks, short-circuits etc.)
▶ LED indicators:
• Ready for operation (green)
• Enable (yellow)
• Error detection of actual pressure value input (red)
Features
Ordering code
Functional description
Block diagram/pin assignment
Technical data
Terminal assignment
Dimensions
Project planning/maintenance instructions/
additional information
Setting recommendation
1
2
2
5
6
7
7
8
9
Bosch Rexroth AG, RE 30214, edition: 2013-04
2/10
VT-MRMA1-1 | Valve amplifier
Ordering code
01
02
VT-MRMA1
–
1
03
–
1X
04
/
V0
05
/
0
06
/
*
01
Analog amplifier in modular design
VT-MRMA1
02
For direct current motor-operated pressure reducing valve (Z) DRS, size 6, component series 1X
03
Component series 10 to 19 (10 to 19: unchanged technical data and pin assignment)
1X
04
Version: Standard
V0
05
Standard option
0
06
Further information in the plain text
*
1
Suitable pressure transducer:
▶ HM20-1X/..-C-K35
(see data sheet 30270)
Functional description
General
The amplifier module is snapped onto top hat rails according to EN 60715. It is electrically connected via 4 plug-in
screw connectors with 4 ports each. The module is operated with 24 V direct voltage.
Power supply unit [1]
An internal power supply unit supplies all internally
required positive and negative supply voltages.
Pressure command value provision [2]
The internal pressure command value signal is generated
from the external pressure command value signal available
at input [2] and the zero point offset [2] (Zw zero point
potentiometer on the front side). If the pressure command
value increases/decreases, the pressure rises/falls. The
differential input can be configured into a 4 to 20 mA
current input via DIL switches S1.1 to S1.6 (see commissioning instructions).
Standard
values
Current
input
Differential
input
Pressure command value at
measuring socket v (position 0)
0%
4 mA
0V
0V
100 %
20 mA
10 V
10 V
A cable break in a pressure command value line will be
detected ("ready for operation" output) and deactivate the
output stage.
Ramp generator [3]
In the ramp generator [3], a provided step signal is turned
into a ramp-shaped output signal. The ramp time relates to
a pressure command value modification of the input signal
of 100 %. The ramp time is not extended or shortened by
the downstream pressure command value attenuator [4].
Bosch Rexroth AG, RE 30214, edition: 2013-04
The ramp times for pressure increase or pressure reduction
can be adjusted separately on the front side of the module
using potentiometers "t <" and "t >". The current ramp time
values can also be checked or pre-set via the switchable
measuring socket (also located on the front side).
Information on ramp time adjustment:
Value at measuring
socket (position 4 or 5) 10 5
Ut in V
Current ramp time
t in s (±20 %)
2 1 0.5 0.1 0.05 0.03 0.02 0.01
0.1 0.2 0.33 0.5 1 2 10 20 33.3 50 100
The following applies:
1 Vs
3
Example measured:
Measurement: Ut = 5 V => t =
1 Vs
= 0.2 s
Ut
5 V
Gw pressure command value attenuator [4]
The Gw potentiometer acts as an attenuator [4] and determines the maximum internal pressure command value. The
setting range lies between 0 % and 130 %.
t=
Linearization of the valve characteristic curve [5]
The linearization [5] is used to compensate the non-linear
valve characteristic curve. The required valve position
command value is generated from the pressure
command value.
Amplitude limiter [6]
The amplitude limiter [6] limits the internal valve position
command value to +110 % and –5 %.
Actual valve position value acquisition [12]
A voltage output is used to supply the position transducer.
The actual valve position value fed back by the position
transducer can be corrected using the Zx zero point potentiometer and the Gx sensitivity potentiometer. The internal
Valve amplifier | VT-MRMA1-1
3/10
Functional description (continued)
actual position value signal generated this way is provided
to the valve position controller [7] for further processing.
Cable breaks in the position transducer lines are detected
via the fault recognition [8].
▶ Cable break of the motor lines
If there is no error, the green "ready for operation" LED on
the front side is lit and the "ready for operation" output is
connected to 24 V operating voltage.
Electronic limit stop
The electronic limit stops are a functional part of the
actual value position acquisition [12].
The adjustable stroke of the valve is mechanically limited.
The used working range is within these mechanical stops.
To prevent the valve from moving into the mechanical
stops when this is not intended (e.g. during setting),
so-called "electronic stops" which are within these limits
have been realized for safety purposes. The valves are
prevented from moving beyond these limits by deactivation
of the output stage. The electronic stops are only effective
if sensor and motor are correctly wired.
Motor protection
The motor protection is a functional part of the fault recognition [8]. To ensure the correct functioning of the valve
actuator, the adjustment time required for each pressure
adjustment process is monitored. If an internally set maximum adjustment time (approx. 4 s) is exceeded, the output stage is deactived to prevent the motor from being
damaged by continuous application of current.
The "ready for operation" output is connected to 0 V and
the green LED on the front side goes out. After the cause
of error has been eliminated, the electronics can be reactivated by resetting and enabling it.
The motor protection detects the following:
▶ Inversion of the motor lines (positive feedback)
▶ Cable break of the motor lines
▶ Jammed valve actuator
0%
100 %
Working range of
the valve
Electronic stop
Mechanical stop
Valve position controller [7]
The valve position controller [7] generates the control
output for the clocked output stage on the basis of the
position control deviation. The position controller has
been optimized for a special valve type.
Output stage [10]
The output stage [10] generates the clocked control voltage for the DC motor acting as actuating element in the
pressure reducing valve. The output stage output is shortcircuit-proof. The output stage is de-energized in case of
an internal fault signal [8] or if not enabled [11].
"Position command value reached" detection [9]
A "position command value reached" output is provided for
as auxiliary process variable. This output is connected
with 24 V operating voltage when the control deviation
from the valve position command value and the regulated
actual valve position value are ≤ 5 % of the nominal stroke
and the internal ramp output signal corresponds to the
provided pressure command value.
Fault detection [8]
The following is monitored:
▶
▶
▶
▶
▶
Cable break of pressure command value lines
Inversion of the pressure command value lines
Cable break of the position transducer connecting lines
Short-circuit of the position transducer supply at L0 (0 V)
Thanks to the integrated motor protection the following
is detected:
▶ Inversion of the motor lines (positive feedback)
▶ Jammed valve actuator
Enable function [11]
The enable function [11] can be used to activate both the
position controller and the output stage via the external
control. The enable signal is indicated by a yellow LED
on the front side of the module.
Internal controller and output stage enable
The controller and the output stage are enabled if the
external enable [11] has been set and the electronics is
"ready for operation", i.e. the fault recognition [8] does not
diagnose any error.
Actual pressure value input [13]
The internal actual pressure value signal is generated from
the signal available at actual pressure value input [13] and
the zero point offset (Zp zero point potentiometer on the
front side). The Gp sensitivity potentiometer can be
used to compensate tolerance-related variations of the
pressure transducer. The input can be configured either
as 0.5 to 5 V voltage input or 4 to 20 mA current input via
the DIL switches S1.7 and S1.8 (see commissioning
instructions) and a corresponding adjustment using
the Zp zero point potentiometer and Gp sensitivity.
Notice: If the input is configured as 4 to 20 mA input and
if the actual pressure value input is connected in series
with another separate external current input, the module
electronics supplies an offset current at terminal 1. This
must be taken into account when adjusting the external
current input.
The following is monitored at the actual pressure value
RE 30214, edition: 2013-04, Bosch Rexroth AG
4/10
VT-MRMA1-1 | Valve amplifier
Functional description (continued)
input (depending on the property of the pressure transducer electronics):
▶ Cable break of the actual pressure value lines
▶ Inversion of the actual pressure value lines
▶ Cable break of the pressure transducer's
operating voltage
▶ Cable break of the pressure transducer's ground
If one of these errors is detected at the actual pressure
value input, both pressure switch signals A and B are
connected with 0 V and the red LED (!) on the front side of
the amplifier module is lit.
Pressure switch function [14]
The integrated pressure switch [14] compares the internal
actual pressure value to a window which can be individually adjusted by the pressure command value
(DIL switches S2.1 to S2.9). Depending on whether the
actual pressure value falls below the lower limit or exceeds
the upper limit, the corresponding pressure switch signal A or B falls to 0 V. If the actual pressure value is within
the pressure command value window, both pressure
switch signals are connected to 24 V operating voltage.
Exception: In case of a cable break of one of the two
actual pressure value lines both signals A and B fall to 0 V.
(Adjustment of the pressure switch thresholds via DIL
switch S2, see commissioning instructions)
Bosch Rexroth AG, RE 30214, edition: 2013-04
Measuring point switch-over [15]
The measuring sockets v and ⊥ on the module front
side can be used to check various internal measuring
points (v0 to v5). The measuring points are selected via
the measuring point selector switch [15] on the housing
front panel.
Switch Measurement signal v
position (⊥ is reference)
Measuring point
Pressure command value wP
0
0 % ≙ 0 V and 100 % ≙ 10 V
Actual pressure value
xP
1
0 % ≙ 0 V and 100 % ≙ 10 V
Valve command value
wS
2
0 % ≙ 0 V and 100 % ≙ 10 V
Actual valve value
xS
3
0 % ≙ 0 V and 100 % ≙ 10 V
Ramp time "up"
t<
4
10 mV to 10 V
Ramp time "down"
t>
5
10 mV to 10 V
Without function
6
0V
Without function
7
< –10 V
Without function
8
< –10 V
Without function
9
< –10 V
Notice:
Switch positions 6 to 9 have no function. They only serve
to determine the switch position in case the arrow mark of
the measuring point selector switch is no longer visible
due to damage.
[ ] = references to the block diagram on page 5
Valve amplifier | VT-MRMA1-1
5/10
Block diagram/pin assignment
t<
S1.1-1. 6
– wP
5
+ wP
6
U/I
t>
3
2
wS
wP
4
U
Zw
t<
7
5, 6
16
PI
U
U
EN
U
11
S1.7–1. 8
1
+ xP
2
U/I
U
GP
13
ZP
L0 (0 V)
1
12
DC
11
+7.5 V
-
M0
DC
–7.5 V
L0
1 Power supply unit
0
1
2
3
4
5
M
2
8
1
+ sensor
3
3
– sensor
13
wP
xP
wS
xS
t<
t>
4
5
4
L0
14
xP
+M
15
xS
78
A
14
901
Operating
voltage
!
12
Zx
S2.1–2. 9
456
– xP
U
Gx
xS
10
–M
EN
23
Enable
xS = w S
9
t>
7
Ready for
operation
9
+
–
Gw
10
8
B
signal v
15
L0
0V
9 Position command value reached – detection
2 Pressure command value provision
10 Output stage
3 Ramp generator
11 Enable function
4 Pressure command value attenuator
12 Actual valve position value acquisition
5 Linearization of the valve characteristic curve
13 Actual pressure value input
6 Amplitude limiter
14 Pressure switch function
7 Valve controller
15 Measuring point switch-over
8 Fault recognition
RE 30214, edition: 2013-04, Bosch Rexroth AG
6/10
VT-MRMA1-1 | Valve amplifier
Technical data (for applications outside these parameters, please consult us!)
Operating voltage
Operating range
UB 24 VDC + 40 % – 20 %
Upper limit value
uB(t)max 35 V
Lower limit value
uB(t)min 21 V
Power consumption
Current consumption
PS < 50 VA
i(t)max (switching on the motor)
< 3.5 A
Imax (during the actuating process)
<1A
Imin (when output stage is switched off)
Fuse
< 120 mA
1.6 A, self-healing (thermal overload protection)
Inputs
– Analog
Pressure command value (differential input)
Pressure command value (current input)
Actual pressure value (differential input)
Actual pressure value (current input)
Ue 0 to +10 V; Re > 100 kΩ
Ie 4 to 20 mA; load RB = 100 Ω
Ue 0.5 to +5 V; Re > 100 kΩ
Ie 4 to 20 mA; load RB = 100 Ω
– Digital
Enable
ON
U +8.5 V to UB; Re > 100 kΩ
OFF
U 0 to +6.5 V; Re > 100 kΩ
Setting ranges
Zero point pressure command value (Zw potentiometer)
±30 %
Pressure command value attenuator (Gw potentiometer)
0 to 130 % 1)
Actual pressure value sensitivity (Zp potentiometer)
±5 %
Actual pressure value amplification (Gp potentiometer)
90 to 120 % 1)
Sensitivity of actual valve position value (Zx potentiometer)
±15 %
Actual valve position value amplification (Gx potentiometer)
90 to 120 % 1)
Ramp times (potentiometer t < and t >)
0.1 to 100 s
Outputs
Output stage
Ueff 0 Veff to UB,eff
Sensor supply voltage
U 0 V and +10 V ± 3 %
Measuring socket
Ready for operation
U 0 V to +10 V ± 2 %; Imax = 2 mA
"Ready for operation"
U > 16 V
(Ri = 10 kΩ; 50 mA)
"Not ready for operation"
U <1V
(Ri = 10 kΩ; 50 mA)
Position command value "Reached"
U > 16 V
(Ri = 10 kΩ; 50 mA)
U <1V
(Ri = 10 kΩ; 50 mA)
Actual pressure value > lower pressure switch threshold
U > 16 V
(Ri = 10 kΩ; 50 mA)
Actual pressure value < lower pressure switch threshold
U <1V
(Ri = 10 kΩ; 50 mA)
Actual pressure value < upper pressure switch threshold
U > 16 V
(Ri = 10 kΩ; 50 mA)
Actual pressure value > upper pressure switch threshold
U <1V
(Ri = 10 kΩ; 50 mA)
"Not reached"
Pressure switch signal A
Pressure switch signal B
Type of connection
4 plug-in screw connectors with 4 ports each
Mounting type
Top hat rail TH 35-7.5 according to EN 60715
Protection class according to EN 60529
IP 20
Admissible operating temperature range
ϑ 0 to +50 °C
Storage temperature range
ϑ –25 °C to +70 °C
Weight
m 0.15 kg
1)
Provided that the zero point has been correctly set
Bosch Rexroth AG, RE 30214, edition: 2013-04
Valve amplifier | VT-MRMA1-1
7/10
Terminal assignment
Actual pressure
value input
Position transducer supply
Pressure command
value input
– xp
1
9
+ xp
2
10
– sensor
Valve connector contact 3
3
11
0V
+ sensor
Valve connector contact 1
4
12
+ UB
– wP
5
13
A
Position command
value reached
xs = ws
Ready for operation
Operating voltage
Pressure switch signals
+ wP
6
14
B
Enable
Enable
7
15
–M
Valve connector contact 5
Actual position
value input
xs
Valve connector contact 2
16
+M
Valve connector contact 4
8
Valve motor connection
Dimensions (Dimensions in mm)
Top hat rail TH 35-7.5
according to EN 60715
Potentiometers
LED indicators
Gw
Pressure command value attenuator
Ready for operation
(green)
Zw
Zero point of pressure command value
Enable
(yellow)
Gp
Amplification of actual pressure value
Zp
Zero point of actual pressure value
Cable break in pressure load cell
(red)
Gx
Actual valve position value amplification
Zx
Zero point of actual valve position value
t<
Ramp time "up"
v
Measurement signal
t>
Ramp time "down"
⊥
Load zero
!
Measuring sockets
RE 30214, edition: 2013-04, Bosch Rexroth AG
8/10
VT-MRMA1-1 | Valve amplifier
Project planning/maintenance instructions/additional information
▶ Prior to installation and commissioning it must be ensured that the DIL switches on the printed circuit board of the
amplifier module have been correctly set (for function of the DIL switches, see commissioning instructions).
▶ DIL switches on the printed circuit board of the amplifier module may only be adjusted when de-energized.
▶ The amplifier module may only be wired or connected and opened when de-energized.
▶ The distance to aerial lines, radios, and radar systems has to be 1 m at least.
▶ Do not lay motor and signal lines near power cables.
▶ The valve is connected with a 5-wire line. For lines up to 50 m in length, use the line type LiYCY 0.5 mm2. For greater
lengths, please contact us.
▶ If the valve line has to be shielded, the shield must be connected to protective earth ("PE") on the module side. In
some cases (e.g. if PE is subject to strong interference) it can be useful to connect the shield directly to the L0 of the
amplifier module, other side open (risk of ground loops).
▶ If a differential input is used, both inputs must always be connected or disconnected at the same time.
▶ Cable ends should not be too short, so as to ensure that the module can still be opened when connected (e.g.: to
adjust the DIL switches).
▶ Ensure that the ground of the pressure command value ("–wP", terminal 5), has the same potential (→ equipotential
bonding busbar) as the ground ("L0", terminal 11) of the power supply unit. This allows for a better suppression
of interferences.
▶ For setting the potentiometers and the measuring point selector switch, use a screwdriver with a blade width of 4 mm.
Bosch Rexroth AG, RE 30214, edition: 2013-04
Valve amplifier | VT-MRMA1-1
9/10
Setting recommendation
Condition as supplied
The condition as supplied of the electronics is characterized by the following features:
• Minimum ramp times.
• Gw attenuator is set to 100 %.
• The linearity of the overall system (module electronics and valve) is subject to deviations in series production.
Fine adjustment of the overall system
Prerequisites:
• The system-specific wiring must have been completed.
• Set DIL switches on printed circuit board of module electronics according to individual requirements.
• Turn on the hydraulic system.
It must be ensured that the hydraulic fluid already has the (regulated) operating temperature for fine-adjustment.
Signal
Setting
1
▶ Set external pressure command value provision to 0 %.
Pressure
command value ▶ Set measuring point selector switch to "0".
zero point
▶ Use the zero point potentiometer Zw to adjust the measurement signal at v: 0 V ± 5 mV (= 0 %).
2
Maximum
pressure
command
value
Notice:
Before adjusting the maximum value, the zero point must be adjusted according to step 1.
▶ External pressure command value provision = 100 %.
▶ Set measuring point selector switch to "0".
▶ Use the potentiometer Gw to adjust the measurement signal at v: 10 V ± 5 mV (= 100 %).
Ramp times
▶ Use the measuring point selector switch to select the potentiometer that is to be set:
▶ Position 4 for ramp "up" t < and position 5 for ramp "down" t >.
▶ Set ramp time according to formula or table (see functional description "Ramp generator")
and check at measuring socket v.
3
4
20 %actual pressure value
Notice:
Prior to the 20 % actual pressure value adjustment the pressure command value must be
adjusted according to steps 1 and 2.
▶ Electrically connect the valve.
▶ Measure sensor supply voltage on the module side between terminals 4 and 3:
+10.0 V ± 300 mV
▶ Set external pressure command value provision to 20 %.
▶ Externally connect enable signal.
▶ Set actual pressure value signal (= voltage between terminals 2 and 1) using Zx to 20 % of the
nominal pressure value:
→ Actual pressure value signal dependent on the pressure transducer used:
Used pressure transducer
Output signal (20 %)
Voltage between
terminals 2 and 1
"0.5 … 5 V" output
+1.40 V
+1.40 V
"4 … 20 mA" output
+7.2 mA
+0.72 V (Rload = 100 Ω)
▶ Set measuring point selector switch to "1".
▶ Use the potentiometer Zp to adjust the measurement signal at v: +2.00 V ± 5 mV.
Continued on page 10
RE 30214, edition: 2013-04, Bosch Rexroth AG
10/10
VT-MRMA1-1 | Valve amplifier
Signal
5
Maximum
actual pressure value
Setting
Notice:
Before adjusting the maximum value, the 20 % actual pressure value must be adjusted according to step 4.
▶ Set external pressure command value provision to 100 %.
▶ Externally connect enable signal.
▶ Set actual pressure value signal (= voltage between terminals 2 and 1) using Gx to 100 % of
the nominal pressure value:
→ Actual pressure value signal dependent on the pressure transducer used:
Used pressure transducer
Output signal (20 %)
Voltage between
terminals 2 and 1
"0.5 … 5 V" output
+5.00 V
+5.00 V
"4 … 20 mA" output
+20 mA
+2.00 V (Rload = 100 Ω)
▶ Set measuring point selector switch to "1".
▶ Use the potentiometer Gp to adjust the measurement signal at v: +10.00 V ± 5 mV.
6
Actual pressure value
▶ Check both working points (steps 4 and 5).
Repeat steps 4 and 5 if required.
7
Individually
adjust the
maximum
pressure
command
value
Set external pressure command value provision according to individual requirements.
Example:
Reduce 100 % external pressure command value to 80 %.
▶ Set external pressure command value provision to 100 %.
▶ Set measuring point selector switch to "0".
▶ Use the potentiometer Gw to set the measurement signal at the measuring socket v according
to the requirements: adjustment according to example: 8.0 V ± 5 mV (= 80 %).
Bosch Rexroth AG
Hydraulics
Zum Eisengießer 1
97816 Lohr am Main, Germany
Phone +49 (0) 93 52 / 18-0
[email protected]
www.boschrexroth.de
Bosch Rexroth AG, RE 30214, edition: 2013-04
© This document, as well as the data, specifications and other information set
forth in it, are the exclusive property of Bosch Rexroth AG. It may not be
reproduced or given to third parties without its consent.
The data specified above only serve to describe the product. No statements
concerning a certain condition or suitability for a certain application can be
derived from our information. The information given does not release the user
from the obligation of own judgment and verification. It must be remembered
that our products are subject to a natural process of wear and aging.
Valve amplifier | VT-MRMA1-1
11/10
Notes
Bosch Rexroth AG
Hydraulics
Zum Eisengießer 1
97816 Lohr am Main, Germany
Phone +49 (0) 93 52 / 18-0
[email protected]
www.boschrexroth.de
© This document, as well as the data, specifications and other information set
forth in it, are the exclusive property of Bosch Rexroth AG. It may not be
reproduced or given to third parties without its consent.
The data specified above only serve to describe the product. No statements
concerning a certain condition or suitability for a certain application can be
derived from our information. The information given does not release the user
from the obligation of own judgment and verification. It must be remembered
that our products are subject to a natural process of wear and aging.
RE 30214, edition: 2013-04, Bosch Rexroth AG
12/10
VT-MRMA1-1 | Valve amplifier
Notes
Bosch Rexroth AG
Hydraulics
Zum Eisengießer 1
97816 Lohr am Main, Germany
Phone +49 (0) 93 52 / 18-0
[email protected]
www.boschrexroth.de
Bosch Rexroth AG, RE 30214, edition: 2013-04
© This document, as well as the data, specifications and other information set
forth in it, are the exclusive property of Bosch Rexroth AG. It may not be
reproduced or given to third parties without its consent.
The data specified above only serve to describe the product. No statements
concerning a certain condition or suitability for a certain application can be
derived from our information. The information given does not release the user
from the obligation of own judgment and verification. It must be remembered
that our products are subject to a natural process of wear and aging.
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement