Transformer Protection

[Basra123]

Most if not all of the PM Transformer are protected with 1) Bayonet fuse and Partial Range Current limiting (PRCL)fuse connected in series with the Bay fuse.
The question how to size such fuses for say 1000 KVA transformer? What is the purpuse of the Bay-o-net fuse?

 

[charlie b]

Re: Transformer Protection

What's a "PM Transformer"?

 

[bob]

Re: Transformer Protection

Check this location for fuse information
http://search.globalspec.com/Search?query=bay%20o%20net%20fuse&show=total&frmtrk=prodsearch
Is this a utiltiy owned pad mount transformer? The primary voltage would determine the range of the fuse size and would be decided by the utility.

 

[jtester]

Re: Transformer Protection

Most if not all of the PM Transformer are protected with 1) Bayonet fuse and Partial Range Current limiting (PRCL)fuse connected in series with the Bay fuse.

I'm not sure that I agree with that, but this type of protection is common for three phase padmounted transformers owned by utilities.

If you aren't governed by the NEC, you would obtain a threshold of damage curve for the transformer. You would use the bayonet fuse to protect the thermal part of the curve, and the current limiting fuse to protect the magnetic portion if you could. The CL fuse would also be coordinated to prevent tank rupture.

If you are governed by the NEC, refer to Article 450.

Jim T

 

[charlie b]

Re: Transformer Protection

Originally posted by bob:Is this a utiltiy owned pad mount transformer?

Am I to infer that the "PM" in "PM Transformer" stands for "pad mounted"? I've not seen that abbreviation used before.

 

[Basra123]

Re: Transformer Protection

Charlie,
Yes this is Pad mount!