Dummy fuse use in Westinghouse safety switch 1

[tem1234]

Hi,

We have a Westinghouse 200 amperes 600 volts safety switch with 200 amperes class R fuse. We do some modification on our distribution system, so a other safety switch will be installed upstream with the same fuse, but we want to keep the first safety switch for a disconnection point and to avoid to replace the cables.

Since we don't want two fuse in serie, can we replace the fuse by dummy fuses "neutral" 200 ampere or we really need to replace the safety switch for a non fusible?

Thanks

 

[jraef]

I think that's fine, but it might be a lot easier to just move the lugs from the lower fuse base up to the switch body.

Unless, because the fuses HAVE been there, your cables are too short.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[melspuds]

For NEC the switch needs to labelled "Disconnect only, nonfused".
The word "neutral" the way you state it is confusing to me. If you mean the dummy fuses as 1 of them as a neutral, that ok, but cables and the dummy fuse must marked with white tape or paint to identify the neutral. In some jurisdictions, require only copper buss bars for the dummy fuses.
Hope this helps and good luck.
Dave

 

[jraef]

I took that to mean the "dummy inserts" to replace fuses. Bussman refers to them as "neutrals" because they are NOT fuses.

http://www.cooperindustries.com/con...lectrical/products/accessories/neutrals_.html

"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[melspuds]

Thanks jraef!
In 50 years of being in the electrical power world, 1st as a electrician, then a EE, and 35 years as PE. I just learn something new about Bussman dummy inserts. I always spec Bussman fuses, clamps, and holders. It is a great day went you learn something new.
thanks
Dave

 

[jraef]

Note the similarity to bus bar or brass pipe... I think it was a good way for them to sell more products with zero R&D!

Kind of like Coca Cola putting the water they use to make Coke into a bottle with zero ingredients, calling it Dasani, then selling it for more than the version WITH ingredients. Brilliant! I think that should be the sequel to Mad Men. I'd love to have seen the marketing meeting where someone first proposed that idea and was laughed at.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[tem1234]

Thanks for the answer.

That's a good solution to move the lug, but the cable will be too short.

The term "neutral" was confusing me also, but Bussman call them this way.

A FAQ on the square d website was confusing me also:
"Square D does not offer a dummy fuse, nor do we support the use of a dummy fuse. We do not UL test our safety switches with dummy fuses, so we have no testing data to support their use. For a non-fusible application, we would recommend using a non-fusible safety switch."

I would use a non fusible switch ordinary, but in this case...I really don't understand what's wrong with using dummy fuse instead of fuse if the protection is done by a fuse upstream.

Maybe we will add a Label "NONfused" as Melspuds mention.