Trip Circuit

[GRP123]

Hi....

This question must be a cake for you.

A transformer feeding a switchgear and the Switchgear has differential and feeder protection.
I am sure all the relays within the switchgear will come wired.

But I have to hook up these relays with external componnet status for differential protection like CT's for differential protection and for temp rise, Alarm contact stuf...etc.

As a consulting engineer, when you receive shop drawings or vendor drawings and then you have to creat new set of drawings for issuing for contractor to wire transformer controls with swithgear which will include trip circuit diagram incorporating feedbacl from transformer components.

I think you can call it a protection diagram..Could you advise, me if I have to understand some basics involved how do I go about it.
I will not be the one doing it but I want to learn it.
My supervisor has no clue so some other office within company will do for us and I will miss the learning curve.

Any internet literature that can help me with this.
Thanks

 

[davidbeach]

I'm not sure you have the order correct.

The engineer developing the design would, at a minimum, create AC onelines and often AC three-line diagrams and DC schematics. The switchgear vendor would then use that information to create wiring diagrams. Once the vendor has created the wiring diagrams, any change in the DC schematics can get rather expensive.

 

[GRP123]

Thanks davidbeach.

The engineer would develop single line diagram and then it woulod go out for tender. Actually the issues i am discussing here pertains to a recent tender we sent out:
ABB, Siemens and GE are the one bidding.

I am a small fish but all these bids will be reviewed by me first hand as I did the specs also.

But I am sure, I will not be the one doing the wiring schematics or what ever you call it :Relay diagram.

http://www.kilowattclassroom.com/Archive/UseStdNos.pdf

This link above shows a glimpse of what I am looking for.



Thanks

 

[davidbeach]

What was the basis for the manufacturers putting a bid together? Somehow there had to be some definition or else you get to compare apples to oranges to kumquats in your bid comparison. True, that definition can take a different form than a schematic diagram, it can be an I/O list or a narrative description but the information had to be conveyed or you will have an incomplete bid package. If that information was made available to the bidders, you may well find that the shop drawing package includes a full set of DC schematics, often referred to as elemental or elementary drawings. If you need to extend those to cover equipment not in the switchgear order, the best thing to do would be to use the vendor drawings as the basis for your drawings and maintain the same style, that will make the drawings far easier to follow in the years to come as maintenance is performed and modifications are made.