Transformer Without REF Protection.

[a430]

Hello Everyone,

I have a project to install an 18.5MVA Transformer, the client beleives he has an excellent and reliable Differential protection and thus doesnt need an REF protection,how do we convince him.

 

[mpparent]

Give the client the pros and cons. If he chooses not to use the protection you recommend, document it and move on.

Mike

 

[dpc]

I agree with mpparent, this is an engineering judgment, not an ethical issue. There are a lot of transformers that size with just primary fuses for protection.

It's the client's transformer and his money.

 

[HiSet]

Hello a430
If the transformer is solidly grounded then I do not see any significant advantage of providing REF protection on top of differentioal protection.

 

[cesgibis]

I think that earth-tank protection can replace the REF and is much easier to implement, however it needs the transfomer to be insulated from earth;

 

[RalphChristie]

It all depends on the transformer winding configuration, the grounding arrangements, the importance of the transformer, how quickly it can be replaced or repaired if an internal fault occurs, and the degree of protection you want to apply. A 18.5MVA transformer is not an of-the-shelf item - in my opinion the more reliable protective schemes, the beter. Depending on the winding configuration, an additional REF-scheme incorporated into the diff-scheme (to obtain a combined REF/diff scheme) can easily be implemented, and it needs just a few extra items.

Finaly, as pointed out by several posters, the final decision depends on the client. Show him the advantages and disadvantages and let him makes the desicion.

[red]Failure seldom stops us, it is the fear for failure that stops us - Jack Lemmon[/red]

Make the best use of Eng-Tips.com
Read the Site Policies at FAQ731-376