Valve amplifier for proportional valves, without electrical position feedback; Maximum current limitation 1 A VT-MSPA2…1A0

Description

• Component series 2X
• Easy valve selection of the Rexroth valves for the industrial hydraulics
• Characteristic curves of the valves stored in the device
• Valve optimization via push-buttons
• All valve parameters adjustable

Features

• For explosion-protected valves with one or two solenoids
• Not in accordance with the Explosion Protection Directive 2014/34/EU
• Command value input 0 ... ±10 V
• Reverse polarity protection of the operating voltage
• Ramp generator up and down is separately adjustable
• Zero point setting
• Command value adjustment
• Characteristic curve generator
• Clocked power output stage
• Output short-circuit-proof
• LED status displays
• Measuring sockets for: actual current value, internal current command/setting

Product description

General

The valve amplifiers are intended for assembly on top hat rails. The electrical connection is established via 3 tension spring plug-in connectors. The supply voltage is 24 VDC.

Power supply unit (1)

The internal power supply unit has a making current limiter to prevent current peaks. Additionally, inverse-polarity protection is integrated.

Command value, command value summing device [3]

The "internal command value" comprises:

• "External command value", connected at the input of the differential amplifier (2)

• Zero point offset (4), "Z/B" adjustable in the standard setup

For pressure valves, a positive command value results in a pressure increase at the valve.

For valve types 4W..., the following applies:

• Via solenoid B, a command value of 0 ... +10 V results in a flow in the valve from P to A and from B to T.

• Via solenoid A, a command value of 0 … -10 V results in a flow in the valve from P to B and from A to T. In the expert setup, you can invert the command value (5) (see operating instructions 30232-01-B).

• In normal operation, the "internal command value" can be measured at the "v" measuring socket.

Ramps

A ramp limits the incline of the command value.

You can choose between a single ramp (6) (one time for all ramps, default value) and a 4Q/2Q ramp (7) (different times for the possible ramps). The 4Q/2Q ramp times are set in the expert setup. The characteristic curve generator (9) does not influence the ramp time.

Command value attenuator "G" (8)

By means of the command value attenuator, the command value can be reduced.

Characteristic curve generator (9)

In the characteristic curve generator, the pre-set valve characteristic curve can be adjusted to the actual hydraulic and control-technical conditions.

The following can be adjusted in the expert setup:

• Pilot current "B"

• Step "S"

• Maximum current "G" (separately possible for solenoid A and B)

Current controller (10)

The solenoid current is recorded, compared to the command value in the current controller and the difference is compensated.

Clock generator (11)

The clock generator creates the clock frequency "f" of the output stage. With Rexroth valves, the clock frequency sometimes changes dependent on the command value and/or the operating voltage.

Power output stage (12)

The power output stage creates the clocked solenoid current for the proportional valve. The solenoid current is limited to the maximum admissible current per output, depending on the set valve. The output stages are short-circuit-proof. With an internal interference signal or in case enable is missing, the output stage will be switched off.

Digital input (13)

The input DI can be set to four different functions:

• 1. Enable (factory setting)

• 2. Command value inversion (permanent enable)

• 3. Ramp on/off (permanent enable)

• 4. Single or quadrant ramp (permanent enable)

Digital output (15)

Device notifies ready for operation if there is no cable break, no internal error and UB ≥ UB min.

See also “Electrical connection”.

Type code

Technical data

(For applications outside these values, please consult us!)

General

Voltage supply

Analog input

Analog output

Digital input

Solenoid outputs

Adjustment options

Measuring sockets

Supplementary information

Electrical connection

Block diagram

Status description LEDs

Description of the LED display 1)

DI	Enable 2)
t	Ramp
Z/B	Zero point / pilot current
G	Command value attenuator
S	Step level command value
☺	Ready for operation
	1st quadrant (positive command value rising)
	2nd quadrant (positive command value falling)
	3rd quadrant (positive command value rising)
	4th quadrant (positive command value falling)

Dimensions

Dimensions in mm

Terminal assignment

Assignment: Switch position/valve type

Project planning information

Project planning information:

• To comply with the safety requirements for the operation of the valve in potentially explosive atmospheres, it must be ensured that the solenoid current does not exceed 1 A. For monitoring and limitation of the valve flow, we recommend using the Rexroth monitoring module VT-MUXA2-2, see data sheet 30290.

• The VT-MSPA2-2X…1A0 valve amplifier and the VT-MUXA2-2 monitoring module may only be installed outside the potentially explosive atmosphere.

• The VT-MSPA2-2X…1A0 valve amplifier and the VT-MUXA2-2 monitoring module are not subject to directive 2014/34/EU.

Maintenance instructions:

• The devices have been tested in the plant and are supplied with default settings.

• Only complete devices can be repaired.

• Repaired devices are returned with default settings. User-specific settings must be made by the machine end-user once again.

Notice:

• In especially EMC-sensitive environments, additional measures must be taken (depending on the application, e.g. shielding, filtration)

• Wiring information
  • Maximum possible spatial separation between signal and load lines.
  • Do not lead signal lines through magnetic fields.
  • If possible, install signal lines without intermediate terminals.
  • Do not install signal lines in parallel to the load lines.
  • Connect cable shields (see operating instructions 30232-01-B)
  • For digital inputs and outputs as well as command and actual value, the max. admissible cable length for unshielded cables is 30 m. For longer cable lengths, shielded cables must be used.
  • The distance to radios must be sufficient (> 1 m).
  • With a strongly fluctuating operating voltage, in individual cases, it may be necessary to use an external smoothing capacitor with a capacity of at least 2200 µF.

• Recommendation: capacitor module VT 11110 (see data sheet 30750); sufficient for up to 3 amplifier modules.

• The upper and lower ventilation slots must not be concealed by adjacent devices in order to provide for sufficient cooling.

Information

VT-MSPA2

Accessories

Shield set for the installation with shielded lines

Ordering codes

Downloads

	Ventilverstärker für Proportionalventile ohne elektrische Wegrückführung, Maximalstrombegrenzung 1 A Data Sheet | RD30232-01 | 2019-09-01 | German | PDF | 549k Product Groups: Analog, Modular design Typ VT-MSPA2…1A0
	Valve amplifier for proportional valves without electrical position feedback, Maximum current limitation 1 A Data Sheet | RE30232-01 | 2019-09-01 | English | PDF | 543k Product Groups: Analog, Modular design Type VT-MSPA2…1A0
	Ventilverstärker für Proportionalventile ohne elektrische Wegrückführung, Maximalstrombegrenzung 1 A Manual | RD30232-01-B | 2022-01-04 | German | PDF | 3.4MB Product Groups: Valve amplifiers VT-MSPA2-2X/A5/1A0/000
	Valve amplifier for proportional valves without electrical position feedback, maximum current limitation 1 A Manual | RE30232-01-B | 2022-01-04 | English | PDF | 3.4MB Product Groups: Valve amplifiers VT-MSPA2-2X/A5/1A0/000