ABB FV4000-VT4 Operating Instruction page 44

Electrical connection
5.2.2.1 Voltage supply, 4 ... 20 mA / HART
Electrical variable
Supply voltage
Supply voltage
Maximum permissible load for the power
supply unit (e. g. display, load)
Maximum permissible load for the output
circuit (determined by the power supply unit)
Fig. 28: Load diagram for current output, load via supply power
In HART communication, the smallest load is 250 Ω. The load R
the available supply voltage U
R =
E
Fig. 29: Current output
1 Low flow
The measurement value output at the current output is as shown in the figure: Above the low
flow, the current is a straight line that would have 4 mA in Q = 0 and 20 mA in Q = Qmax
operating mode. Due to low flow cutoff, the flow is set to 0 below x % Qmax or the low flow (in
other words, the current is 4 mA).
44
[k ] Ω
R
B
1,6
1,4
1,2
1,0
0,8
0,6
0,4
0,2
0,0
10
U
S
I
B
20 mA
4 mA
FV4000-VT4/VR4 / FS4000-ST4/SR4
Value
U ≥ 14 V DC
B
U = 14 ... 46 V DC
S
R
B
R
15 20 25 30 35
and the selected signal current as follows:
S
0
U [V, DC]
S
40 45 50
G00644
is calculated on the basis of
E
Q
Qmax
G00648
D184B097U02