Difference between cold loop check and hot loop check? (http://engineersinterview.com/questions/category/instru mentation/) Instrumentation (http://engineersinterview.com/questions/category/instrumentation/) April 14, 2016
Vami (http://engineersinterview.com/user/Vami/) (http://engineersinterview.com/user/Vami/) selected answer April 14, 14, 2016 (http://engineersinterview.com/question/difference-between-cold-loop-
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check-and-hot-loop-check/)
what do you mean by Loop checking ? What are the cold loop check and hot loop check? what are the difference difference between between these two loops? Comment
A Cold Loop check is cold because it is done without powering power ing the loop. A cold check consists of checking wire continuity from t he 迌eld instrument through j unction boxes and through DCS/PLC marshalling panel terminals to the control panel. Once continuity has been con迌rmed, then a Hot Loop Check is performed on the Loop’s Loop’s I/O. A Hot loop check is ‘hot’ because it is done with the loop powered up. A Hot loop check consists of – simulating a process input at the 迌eld instrument and then checking the instrument’s output and the response to the process signal input at DCS/PLC. – simulating outputs at the control end and checking for correct response at the 迌eld end. Comment
http://engi ne neer si si nt nter vi vi ew ew.com /q /questi on on/di ffffer en ence- be between- co col dd- lo loop- ch check- an and- ho hot- lo loop- ch check/
