Batch reactor-Temparature tansmitter loading

Hi guys,
     Our batch reactor in process lab has duplex type RTD.It placed at bottom side of reactor.Here is the problem reagrding same RTD and Transmitter while checking its loop From DCS to field.
 Problem is:

•   Reactor temperature control module showing BAD device indication.It means either device is not connected or its not working

 While searching the root cause of problem we did following steps :

• Started with RTD checking.Measured resistance between 3 Terminal RTD and found it is ok at room temparature.
• Next we checked voltage comming from DCS to tansmitter.As it is duplex RTD we got 11.5 V and 13 V at both transmitter.so we decided to check the loop.
• Firstly in process lab upper junction box we checked cable continuity and we found it ok.Cable tag number 25/Ax AI/41 n so on...so from this we can esily found the same cable in DCS lab and for cross checking checked its continuity in JB.
• We found 24 V coming from DCS by rmoving cable from field instrument but when we were connecting same cable to transmteer voltage drop had occured so the module is showing device is not connected or failure as 24V loop is not completed.
• Now we are checking Transmitter ,so we can make conclusion why voltage drop occuring may be its because of transmitter load.

Just do the same steps when your checking loops in plant.These small things lead you good Instrumentation and control engineer.

take care........
     







     

Batch reactor

Hello....after a long break of our practical work because of  our exams n presentations we were unable to post the recent interesting happenings in our batch reactor pilot plant....

     Its not the meaning that we were not working on that..We worked on interesting concept of  looping .I am saying interesting as it was done previously by the pilot plant developers.After some days the inlet valves are not working.

     We found relay number 12 also not working....so we traced whole loop and finally found one bug in card channel which itself not producing 24 v DC.Now we changed card number and channel number.Now as relay number 12 is working he Inlet valve center one is working now.

     Second problem i found when whole loop is ok but simple fuse in Marshalling cabinet is not working means just blown. we replaced it and checked ,the valve is working now.

      U might think its a just routine maintenance problem but in our opinion if we are able to find those problems and we solve it then it clears our ideas of field instrumentation specifically...I already posted diagram of this batch reactor so you can check which valves were not working(inlet valves).

  Relay card picture also posted in previous blog..

    

Thanks to all...

Bottle filling control panel

Delta v explorer

we were busy in our exams and now we are back to work .....so here are some steps to become familiar with delta -v explorer

Following are the steps to assign module in delta-v explorer

1.Open delta v explorer

2.If u want to create class based module then open library-go to control module class- wright click on it  n say new module-finally name it and build the module like-analog input,analog output or digital input etc

3.den go to system configuration-control strategies-write click-create your area-open your ara n crate new module .

4 You can use the module which you crated in control module class above explained or you can crate new module here itself which is not class based ..

IMP question is-whether there is significance to use class based  control module????

Batch process flow diagram-in our case

Delta v explorer

Following are the steps for making 'Control module class' and 'Area in control strategies' :
1. open delta v explorer
2.go to library
3.enter into advance definitions
4.there are many class like equipment module class,control module class,etc
5.right click on it n create new class-eg valve and open it with control studio and take whichever input you required.
 Benefits: 1. if u need valve that is DO in area for many times then just darg valve from its class n rename it .


Steps for making area:
1. go to system configurations
2. enter into control strategies
3.right click and make new area.
   eg-M-tech

Discussion regarding DCS and PLC in our case

1.DCS- master
2 PLC- slave
       these combination we are going to use to run the plant.
- bottle filling application is on PLC which we are doing
- the major parr as tank level,temparature,mixture content,agitator,mass are controlled through DCS
-so suggest your control strategies.
-regarding basic information or quries post here