VEGA WEIGHTRAC 31 4 … 20 mA_HART - four-wire - Manual (Page 66)

66
10 Supplement
WEIGHTRAC 31 • 4 … 20 mA/HART - four-wire
42374-EN-131119
Ʋ Internal load 250 Ω
Switching input
Ʋ Type of input - Open Collector 10 mA
Ʋ Type of input - Relay contact 100 mA
Output variable/Mass flow rate measurement
Output signals
4 … 20 mA/HART - active; 4 … 20 mA/HART - passive
Range of the output signal 3.8 … 20.5 mA/HART
Terminal voltage passive 9 … 30 V DC
Shortcircuit protection Available
Potential separation Available
Signal resolution 0.3 µA
Failure signal current output (adjustable) 22 mA, < 3.6 mA
Max. output current
22 mA
Starting current ≤ 3.6 mA
Load
Ʋ 4 … 20 mA/HART - active < 500 Ω
Ʋ 4 … 20 mA/HART - intrinsically safe < 300 Ω
Damping (63 % of the input variable) 1 … 1200 s, adjustable
HART output values
Ʋ PV (Primary Value) Mass flow
Ʋ SV (Secondary Value) Electronics temperature
Ʋ TV (Third Value) Mass coefficient (e.g. in kg/m)
FV (Fourth Value) Pulse rate
Relay output
Output
Relay output (SPDT), floating spdt
Switching voltage
Ʋ Min. 10 mV
Ʋ Max. 253 V AC, 253 V DC
Switching current
Ʋ Min. 10 µA
Ʋ Max. 3 A AC, 1 A DC
Breaking capacity
Ʋ Min. 50 mW
Ʋ Max. 750 VA AC, 40 W DC
If inductive loads or stronger currents are switched
through, the gold plating on the relay contact surface will
be permanently damaged. The contact is then no longer
suitable for switching low-level signal circuits.
Contact material (relay contacts) AgNi or AgSnO and Au plated