# Type of fuses in 200A service disconnect



## jablonski (May 29, 2010)

This one client today said they had issues with their fuses in a main disconnect located in the house. A 200A fuse blew on two occasions, once in winter when the furnace kicked on, and another lately with the AC, dryer and oven on. They have a FLNR 200A ID type fuse. I thought those were the right ones, but am I wrong? Why would they keep on blowing, especially happening with two different loads.

Thanks for any replies!


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## backstay (Feb 3, 2011)

Do you have a lose connection at the fuse? I would replace the disco and install a breaker. I did one this summer alread, 200 amp main fused CH loadcenter.


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## MDShunk (Jan 7, 2007)

Use low peak fuses and do an fop test. I suspect the fuseholders are beyond their useful life also.


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## micromind (Aug 11, 2007)

MDShunk said:


> Use low peak fuses and do an fop test. I suspect the fuseholders are beyond their useful life also.


Ditto.

Especially the FOP test. Don't go across the fuse itself, go from the holder to the fuse. Both ends.


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## jablonski (May 29, 2010)

Thanks guys, did a bit of research and found out what a FOP test is... learning something new every single day!


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## GEORGE D (Apr 2, 2009)

What is it?


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## Jlarson (Jun 28, 2009)

GEORGE D said:


> What is it?


Measure the voltage drop across a connection or contact under load. The higher the VD the higher the resistance leading to other issues.


Calls like this are why I keep some fuse clip clamps around, good for temp repairs and well sometimes less temporary ones.


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## E. Henderson (Aug 15, 2011)

*Liked the quote...*



Jlarson said:


> Measure the voltage drop across a connection or contact under load. The higher the VD the higher the resistance leading to other issues.
> 
> 
> Calls like this are why I keep some fuse clip clamps around, good for temp repairs and when sometimes less temporary ones.


...about the best electricians never stop learning....


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