Dräger Polytron 7000 Instructions For Use Manual page 45

1)
Analogue
Measured signal
Zero-point
Full-scale value
Sensor drift below zero-point
Over range
Fault signal
Fault at the 4-20 mA interface > 23 mA
Maintenance signal
Warning signal
Update rate of the 4-20-mA
interface
Digital
1) Factory setting – Depending on the configured current offset, the values can deviate by
±0,05 mA.
Overshooting or undershooting of the specified supply voltage of the gas
detector can lead to faulty indication by the 4 to 20 mA signal.
For applications in compliance with Directive 2014/30/EU, the gas detector should
not be operated with a direct current supply grid but with a power supply unit
conforming to Protection class II or NEC Class II.
Analogue signal transmission (2-wire)
Supply voltage
(without pump or relay module)
at a current of 3 mA
at a current of 20 mA
AC voltage component
Analogue signal transmission (3-wire)
Supply voltage
(without pump or relay mod-
ule)
AC voltage component
Load
1) Actual supply voltage on the gas detector
Dräger Polytron 7000
4 ... 20 mA
4 mA
20 mA
3.8 ... 4 mA
20 ... 20.5 mA
<3.2 mA
Static signal: 3.4 mA (factory setting)
Range which can be set:
1.0 ... 3.5 mA (3-wire operation)
3.0 ... 3.5 mA (2-wire operation)
Dynamic alternating signal: 5 mA for
0.4 seconds and 3 mA for 0.7 seconds
Dynamic alternating signal between measured
value and warning level.
Range which can be set (warning level):
3.0 ... 3.5 mA (factory setting: < 3.2 mA)
Intervals:
T1: 2-60 seconds
T2: 1-59 seconds and also dependent on T1
1 second
®
HART -compatible,
Transmission via 2 or 3-core shielded cable
16.5 ... 30 V DC
8.0 V DC min.
< 0.5 V
SS
12 ... 30 V DC
< 0.5 V
SS
0 Ohms ... 40 [Ohms/Volt] x (U
Technical data
S 1)
- 4 V)