Hi Frnds , If Suppose 1 Pair cable of 1.5 sq mm is used for
Transmitter and instead of 1.5 sq mm if i used 0.5 sq mm
cable will the resistance change will occur and does it
affect our transmitter reading. plz mail ur answer to
ntnkamble@gmail.com plz immediately mail ur reply
It depends on how much voltage the field transmitter needs to operate and the total loop resistance of the loop circuit .
Every 2 wire loop powered transmitter has a specification for the voltage required to drive a given loop resistance. Sometimes that is a formula, sometimes a load line graph, sometimes a statement like "minimum liftoff voltage is 17.7V", or rarely, a vague statement of maximum loop resistance (common with active analog outputs, rare with loop powered transmitters)
Excessive wire resistance in a 2 wire loop powered transmitter circuit can affect the operation by
- preventing the transmitter from turning on and operating
- allowing partial operation at lower current outputs, but failing to operate at higher current outputs. That failure can be either an output that just never exceeds a certain value or a transmitter that cycles on-off-on-off an never initializes.
If there is sufficient voltage to run drive the total loop resistance, then the transmitter could function normally.
You need to calculate the wire resistance over its total wire run length (out and back) and know what the receiver's analog input resistance is. Then look up the specification for how much resistance the transmitter's can drive and see whether your loop resistance is lower than the maximum.
Carl Ellis
Measure First
Is This Answer Correct ? | 0 Yes | 0 No |
Is there any interfacing sofware to build communication between a PC and ER300P model L&T make trivector meter via RS485 port which is available in the meter and is there any data acquisition card available to store the acquired data from the meter into the system
What is heating effect?
0 Answers Process Control Technologies,
what is the zero and span trim?
why we are using boosters at glass furnace is there any other thing?
Please any one can provide latest aptitude test,technical test and interview questions for tata consulting engineering (TCE) i need it asap thanks in advance
Valve positioner and actuators in detail.
What is a PID?
what is full form of NAK?
WHAT IS AN INTERLOCK SYSTEM ?? HOW THEY WORKs ?? WHERE IT IS USED ??? MAINLY ??
2 Answers TATA, Tata Steel Limited,
what is dry leg and wet leg in transmeter calibration?
what will the sending unit in the fuel gauge utilizes?
what is commissioning & pre commissioning , explain with difination
2 Answers Bapco Bahrain Petroleum Company, Shell,