Transformer Secondaries

[domeng]

Does the NEC require a single protection device for secondary feeder from a transformer to a Power Panel if the feeder is less than 10 feet?

 

[byourdesky]

Look at 450.6 (B)

 

[Karl H]

240.21 (c) 2008 nec

 

[byourdesky]

240.21 (c) 2008 nec

Thats what I meant :grin:

 

[jim dungar]

Look at 450.6 (B)

Article 450 deals with protecting the transformer.

As Karl mentioned, Article 240 is for conductor protection.

 

[domeng]

Electrical Consultant

Electrical Consultant

Article 450 deals with protecting the transformer.

As Karl mentioned, Article 240 is for conductor protection.

My basic question is do I need a single protective device or are multiple protective devices acceptable?This is not a network transformer and primary protection may not be sized to protect the secondary conductors

 

[sandsnow]

My basic answer is yes, multiple devices are acceptable. Note conditions in 240.21(C)(3)

 

[raider1]

Also take a look at 408.36(B). This feeder is supplying a panelboard.

Chris

 

[dcspector]

Also take a look at 408.36(B). This feeder is supplying a panelboard.

Chris

Good reference. I had forgotten about that one. Funny we see transformers we go to 450 and secondaries to 240.21 and forget about certain "Key Words" as in feeding a "PANELBOARD"...408

Thanks Chris!

 

[sandsnow]

Also take a look at 408.36(B). This feeder is supplying a panelboard.

Chris

Oops, looks like I was wrong.

Section 408.36(B) trumps the rules in 240.21(C)(3)

 

[raider1]

Good reference. I had forgotten about that one. Funny we see transformers we go to 450 and secondaries to 240.21 and forget about certain "Key Words" as in feeding a "PANELBOARD"...408

Thanks Chris!

Your welcome.

I agree, sometimes we don't think about what the transformer is feeding and just look at 240.21(C) and 450.3(B).

Chris

 

[dcspector]

Your welcome.

I agree, sometimes we don't think about what the transformer is feeding and just look at 240.21(C) and 450.3(B).

Chris

Agreed and thanks again for blowin out the cob webs man.

 

[Karl H]

Bravo Raider!! 408.36 is an ART I have'nt read in a long time.

I think this forum should be an approved CEU.

 

[Karl H]

No wonder it's been awhile since I've read 408.36. It used to be 384.16 (b).