Fuse reducer 800A to 125A

[victor.cherkashi]

I have to connect (4) sets 4#400MCM on the load side of a disconnect because of tap rules, so I specified EATON DH327FGK (800A. 3-pole). I need only 125 Amp feeder downstream of the disconnect, but the contractor says he can't fit/install 125 Amp fuses into 800A disconnect. I expected that fuse reducer can be used for almost any size.
I left a question for the support team on the EATON website but no response so far.

DH327FGK | Eaton enhanced visible blade single-throw fused safety switch | Eaton

DH327FGK - Eaton Enhanced visible blade single-throw safety switch, 800 A, NEMA 1, Painted steel, Class L, Fusible without neutral, Three-pole, Three-wire, 240 V, Max Hp: 100 hp (3PH @Std), (4)#1/0-(4)750 kcmil Al

www.eaton.com

Any input will be appreciated

 

[tom baker]

Bluesman makes fuse reducers, 800 to 125 is a large reduction, check busses catalog.

 

[qcroanoke]

We've used 400 to 200 but I would be surprised to see a 800 to 125 reducer. Is there an actual size difference in a 800 amp fuse compared to a 400?

 

[jim dungar]

I have to connect (4) sets 4#400MCM on the load side of a disconnect because of tap rules, so I specified EATON DH327FGK (800A. 3-pole). I need only 125 Amp feeder downstream of the disconnect, but the contractor says he can't fit/install 125 Amp fuses into 800A disconnect. I expected that fuse reducer can be used for almost any size.

We've used 400 to 200 but I would be surprised to see a 800 to 125 reducer. Is there an actual size difference in a 800 amp fuse compared to a 400?

Yes, a huge difference.

800A are Class L bolted style while 600A and smaller are ferrule style (clip style) usually Class R.

 

[augie47]

Can you move your 200amp (125) disconnect close enough to the 800 amp to use the 25ft or 10ft tap rule.

 

[Todd0x1]

Don't know if this helps or not but Mersen makes Class L fuses in 100 and 150 amps that are the same mounting size as the 800A one. Check the datasheet below.

https://ep-us.mersen.com/sites/mersen_us/files/DS-A4BQ-Class-L-Time-Delay-Mersen.pdf

 

[electrofelon]

I remember pricing fuse reducers once and it was cheaper to replace the disconnect...

 

[victor.cherkashi]

Can you move your 200amp (125) disconnect close enough to the 800 amp to use the 25ft or 10ft tap rule.

The disconnect will be in adjacent room, there is no way to achieve 10 ft or less

 

[victor.cherkashi]

Don't know if this helps or not but Mersen makes Class L fuses in 100 and 150 amps that are the same mounting size as the 800A one. Check the datasheet below.

https://ep-us.mersen.com/sites/mersen_us/files/DS-A4BQ-Class-L-Time-Delay-Mersen.pdf

I will look into it, thank you for a clue