Explain about 4 wire instrument concept & tell about its wiring fron senso

Explain about 4 wire instrument concept & tell about its
wiring fron sensor in Field to PLC panel.Explain with an
example?

Question Posted / chandrasekarapandian

3 Answers
13012 Views
IOCL, I also Faced
E-Mail Answers

Answers were Sorted based on User's Feedback

Explain about 4 wire instrument concept & tell about its wiring fron sensor in Field to PLC pa..

Answer / ranjith_asp

As the name suggests, these instruments will have 4 wires
connected to its Terminal Block. Take a Pressure Transmitter
for example
- 2 wires are for Power Supply. Typically 24VDC. This is to
power the instrument to make it work. These 2 wires will be
routd via a JB and then connected to a power supply module
in the PLC cabinet.
- remaining 2 wires are for 4-20mA signal transmission. This
output signal will be proportional to the measured Pressure.
These 2 signal wires will be connected to the AI card in the
PLC cabinet.

Is This Answer Correct ?

6 Yes

0 No

Explain about 4 wire instrument concept & tell about its wiring fron sensor in Field to PLC pa..

Answer / hadi

4 wire connection sensor have two methods:
1-sensor's power is provided from card
2-sensor's power is provided from field
in first method the power is +24VDC and the current limit
exist but in second method the power is every thing and
transmitter feed from external power supply.
in two methods the signal lines and power lines are different.

Is This Answer Correct ?

6 Yes

2 No

Explain about 4 wire instrument concept & tell about its wiring fron sensor in Field to PLC pa..

Answer / ramaswamy and karuppusami

Usually in 2wire transmission, 24v supply is given and o/p
in mA are taken through single pair cable. e.g: Transmitters.

But in 4wire system, supply is provided in separate single
pair cable and o/p is taken through another cable. e.g :
local speed indicator device: i/p = 230v and o/p = 4-20
mA(Both are in separate cables ).

Is This Answer Correct ?

3 Yes

0 No

Post New Answer

More Instrumentation Interview Questions

how to calibrate 0- 150 psi presure gauge by dead weght tester

0 Answers

steam drum level transmitter calibration procedure? with example?

1 Answers

What is cavitation. what is the effect of it on control valve and how is it prevented.

1 Answers ADMA OPCO,

How to Calibrate Flammable gas detector in field

0 Answers

How to Calibrate Level Troll in field

0 Answers

if in a level tx height is given, how u calculate the ranges of the tx?

2 Answers Bombay Rayon Fashions, Invensys,

what is pico fuse? how this different rom othe fuses and how to locate it inside the card?

1 Answers

what is the zero and span trim?

2 Answers

i have been asked by QAFCO to appear for interview for thy post of Instrument Designer(INTOOLS)..i m engineering graduate with 5 years exp. in design engineering.Will this job profile suit me??i need all ur help n suggestions for thy same?

0 Answers QAFCO,

What is glanding

1 Answers

what is the difference between the microcontroller and PLC?

9 Answers HAL, Havells,

How will you change the action of a control valve?

1 Answers CCIE,

For more Instrumentation Interview Questions Click Here