4-18
MAN0448_Issue 13_01-2010
5704 Control System
005704-M-5001 A03249
CHAPTER 4 - INSTAllATION INSTRUCTIONS
11.5 4 - 20mA loop Powered Sensors:
The maximum line resistance of cabling for a 4 - 20mA loop powered
sensor varies with the voltage drive requirements of the type of sensor
installed. It is also subject to a 24V maximum loop drive voltage.
Maximum line loop resistance is calculated as follows:
24 - V
s
R
L
=
0.025
Where: R
L
=
Total Line Resistance (ohms)
V
s
=
Minimum Sensor Operating Voltage (V)
11.6 4 - 20mA Transmitters
The maximum line resistance of cabling for a 4 - 20mA transmitter
powered from the System 57 varies with the voltage and current
requirements of the transmitter. It is also subject to the minimum supply
voltage available from the System 57.
Maximum line loop resistance is calculated as follows:
V
r
- V
s
R
L
=
I
s
Where: R
L
=
Total Line Resistance (ohms)
V
r
=
Minimum DC Supply to System 57 (V)
V
s
=
Sensor Voltage (V)
I
s
=
Sensor Current (A)
Making the above calculation using a V
r
of 18V will accommodate the
worst case low dc supply situation.
The maximum resistance
per core
can be calculated from the above
configurations as follows:
R
L
Maximum Resistance of Core =
ohms
2
Summary of Contents for 5704
Page 1: ...System 57 5704 Control System Operating Instructions ...
Page 4: ...4 MAN0448_Issue 13_01 2010 5704 Control System 005704 M 5001 A03249 ...
Page 6: ...6 MAN0448_Issue 13_01 2010 5704 Control System 005704 M 5001 A03249 User Notes ...
Page 14: ...1 8 MAN0448_Issue 13_01 2010 5704 Control System 005704 M 5001 A03249 User Notes ...
