Fuse switch 1

[Indy]

Good afternoon,
We have a fuse switch 100A-415v fairly old as it is Gec. We are planning on reusing it for equipment that will come in at around 40A. Our contractor says it is as simple as replacing the fuses with ones rated for the new equipment. I think more work would be required, has anyone came across this before?

Thanks

 

[wbd]

If it is rated for the new voltage, is maintained and the 40A fuses will physically fit, I don't see anything wrong with that. Do you have some specific concerns?

 

[waross]

Check the Available Short Circuit Current rating.
Over the years distribution transformer impedances have dropped and the ASCCs have risen.
The switch may no longer be safe to use on your supply transformer.
If the circuit is modified it is no longer "Grandfathered" and may no longer be approved.

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

 

[ScottyUK]

Other than questioning why you'd re-use a board that has seen its 30th birthday and may well be a lot older than that, your contractor is right: you can almost certainly get a 40A or 50A BS88 fuselink in a body size which is compatible with the switch fuse.

 

[waross]

Fuse reducers are another option.

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

 

[wbd]

Check the Available Short Circuit Current rating.

Good point but typically a disconnect switch with a fuse in it, is rated around 100kA or what the fuse rating is. Non-fused disconnect switches are typically rated at 10kA

 

[ScottyUK]

GEC's switch fuses use fuselinks conforming to BS88 which are rated for up to 80kA.

 

[Indy]

Thanks for the replies. I just assumed there would be more work involved than changing out the fuses because of the age of the board. The new equipment will have a control panel containing a vsd.
Thanks