Answer / ripul ghosh

nowadays 24V DC relays are used compared to 230V what was used before..relays are mainly there to isolate the controller from high power lines,
The signal from the controller will come to the relay and it will get energised to drive the output load.

Answer / nirmalya basu

to energise a output by plc and for its protection purpose
also.

Answer / ganesh

the relay works with AC and DC.
it provide the isolation between controller and devices works on ac and dc.
it is extremely useful when you need to control a large amount of current or voltage with small electrical signal.

Answer / suresh agravat

Example pressure transmitter input showing fiied full with liquid than send singnal through output to relay. When relay deenergised motor contactor not get supply and it will be motor or pump stop. Relay is basically on/off switch

How to define the size of control valve?

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Hi, I'd like to know the purpose of MOS (maintenance override switch). At site, these switches are installed in a stanchion with the transmitter (connected to ESD). thank you.

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what is solenoid valve?

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hiii.... can any one provide me previous years question paper of hindustan petroleum for instrumentation engineering???

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i am from instrument branch i want paper patern of mahagenco . any pevious years paper regarding my branch send me please . please.....

1 Answers  

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