Description of the current loop (dvr 4s) – VACUUBRAND DVR 4S User Manual
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Documents are only to be used and distributed completely and unchanged. It is strictly the users´ responsibility to check
carefully the validity of this document with respect to his product. manual-no.: 99 90 72 / 13/08/2005
Description of the current loop (DVR 4S)
Note: Pressure measurement and output of the measured value starts as soon as the supply voltage is
connected to the current loop. This is independent from switching on the device with key ON/OFF (switches
on the display).
☞ The lifetime of the power supply unit increases as the display is not switched on.
Attention: In case of applied power supply permanent vacuum measurement occurs, which may cause
a reduced lifetime of the power supply. The interface provides only a means of communication and
doesn’t serve as current supply.
Electrical description of the current loop
Operating current 4 .... 20 mA
Supply voltage 5 .... 30 V
Consider the cable resistance for determination of the load resistance.
1
2
3
4
Electrical connection
(view from outside)
1: current loop +
2: current loop -
3: N. C. (not connected)
4: N. C. (not connected)
Safety specifications
Connect the current loop only to an intrinsically safe signal circuit: Electrical equipment of the facility
performance group II category (2) G, approval: EEx ia IIC.
Max. connection parameters:
Max. supply voltage: U
i
= 30 V
Max. supply current: I
i
= 100 mA
Max. internal parameters:
Capacitance: C
i
= 64 nF
Inductance: L
i
= 60 µH
If an isolating interface unit is connected, respect the following maximum values:
Max. supply voltage: 30 V
Max. supply current: 100 mA
Series resistance: 300
Ω
The mounting angle of the connector can be changed in steps of 90° (factory-set: cable below).
Max. cable diameter: 8 mm
Max. wire diameter: 0.75 mm
2
A non-shielded cable can be used.
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