Unknown fuse class 2

[weber05]

I am dealing with some very old fuses in some 220V lighting panels. All I can read on the in Trico renewable fuses. CM-5. and thats about it. I am doing a load study because a very small dry type transformer burned up and we think it is because it was over fused, (more than 250% on the primary side as well as the secondary side...) any ways, any of you old timers familiar with "TRICO" fuses?

 

[Zogzog]

Went out of businees years ago, now they make greases pr something. Call Monster, they will get you a replacement.

 

[dpc]

Any renewable fuses are probably quite old and should be replaced with new current-limiting type. Monster Fuse should be able to help, as Zogzog said.

 

[weber05]

I am currently using ETAP, and I'm trying to simulate what might have caused the fire. My thinking is that the fire in the transformer could have been avoided if it had the proper protection on the primary and the secondary side. It is clear that it is already overfused, but I was wondering what class of fuse I should label this as in my ETAP model. Trust me, these fuses are going to be replaced, and sized appropriatly, but to simulate the senerio i'd like to get a good idea of what class to use.

 

[dpc]

Check the Cooper/Bussman website for guidance on recommended fusing for transformer protection.

There are requirements in NEC Article 450 as well.

 

[weber05]

I know how to PROPERLY protect a transformer, the proplem is this particular transforer was FAR from any ANSI, NEC, IEEE standards or recomendations. Basically I would like to know how these old fuses compare to newer ones, so I can substitute them into ETAP. any fuse that Ferraz, bussman, or halfway repuatable fuse maker has on the market I have access to, but due to how old these fuses are I am at a loss as far as how to classify them.

 

[dpc]

The closest thing in a currently made fuse is probably a NON type. But if you don't know the ampere rating, I'm not sure how this is going to help.

 

[waross]

Old transformer, old fuses, renewable fuses that were often overfused or double fused. Stuff happens. Put it behind you and get back to useful work.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[weber05]

Well, when your a coop, theres not much useful work that they give you. Thank you DPC for all the help. maybe in a year and I work out here full time things will be different, but until then this is all I have. That's actually what I have been using, there were three lighting panals and a disconnect switch, 2 were 60 amp bussman NON types, one 100A trico, and one 150A trico, I used NON in my simualtion for all of them, but I wanted to confirm that would be a close comparison. again, thank you all for the help, and hopefully before summers end I will get to utilize this forum with a question worth asking..

 

[waross]

I apologize. I didn't realize your situation.
A tip from the days, generations ago, when we thought renewable fuses were great.
We had so many fuse failures that each MCC had a cabinet on the end with an assortment of replacement links.
We tried NON fuses and our fuse replacements were decimated.
I have found replaceable fuses to be unreliable and prone to failure.
I would be tempted to use 65A to 80A NON as equivalent to 100A renewables, with a high uncertainty factor, for a simulation.
Does this sound reasonable, dcp?
Remember that the rating on the barrel is the maximum, but they were typically fused at the maximum. Also, double linking was some times used.


Bill
--------------------
"Why not the best?"
Jimmy Carter