Fused Switchgear

[mbrooke]

Is there a manufacturer (Eaton, Siemens GE) that still offers 5000 amp fused switchgear standard? I can't find anything on their sites above 1,200 amp.


Second, is fused gear common in new installations? I see tons of buildings from the 70s with fused gear almost exclusively but everything new seems to be power circuit breakers.

 

[Besoeker3]

Is there a manufacturer (Eaton, Siemens GE) that still offers 5000 amp fused switchgear standard? I can't find anything on their sites above 1,200 amp.


Second, is fused gear common in new installations? I see tons of buildings from the 70s with fused gear almost exclusively but everything new seems to be power circuit breakers.

Have you tried ABB?

 

[mbrooke]

Have you tried ABB?

No

 

[wbdvt]

S&C Electric makes fused switchgear from 5kV to 34.5kV

 

[mbrooke]

S&C Electric makes fused switchgear from 5kV to 34.5kV

I know, but I'm looking for 600 volts and under.

 

[infinity]

We've been using Eaton for years and our service gear is typically 4000 amps with fused switches.

 

[ron]

Is there a manufacturer (Eaton, Siemens GE) that still offers 5000 amp fused switchgear standard? I can't find anything on their sites above 1,200 amp.


Second, is fused gear common in new installations? I see tons of buildings from the 70s with fused gear almost exclusively but everything new seems to be power circuit breakers.

If you are talking about fused circuit breakers, most folks offer fused SWGR at 5000A at high short circuit ratings (200kA). If you are looking for just SWGR with fused switches instead of fused CBs, most will put bolted pressure switches in a line-up but it is SWBD (891 instead of 1558).

Your 2nd question again depends on whether you mean fused switches or fused CB's. In both cases, both are available vintage and new.

 

[mbrooke]

If you are talking about fused circuit breakers, most folks offer fused SWGR at 5000A at high short circuit ratings (200kA). If you are looking for just SWGR with fused switches instead of fused CBs, most will put bolted pressure switches in a line-up but it is SWBD (891 instead of 1558).

Your 2nd question again depends on whether you mean fused switches or fused CB's. In both cases, both are available vintage and new.

Maybe I'm way off, but SWBD seems limited to 1,200amps.


Fused switches (capable of breaking full load current), brand new.

 

[ron]

Maybe I'm way off, but SWBD seems limited to 1,200amps.


Fused switches (capable of breaking full load current), brand new.

Nope, I specify SWBDs all the time at 4000A and 5000A. Especially Schneider Square D QED-6 which has some of the benefits of SWGR. I'm liking the new Eaton PRL-XD SWBDs up to 6000A which I haven't specified yet. Just not the 30 cycle rating, but just about everything else.

 

[mbrooke]

Nope, I specify SWBDs all the time at 4000A and 5000A. Especially Schneider Square D QED-6 which has some of the benefits of SWGR. I'm liking the Eaton PRL-XD SWBDs up to 6000A.

Any reason why there is no switch gear option? Switchboard will (should) work just fine for me but still curious why not SWGR.

 

[Tony S]

I’ve never known of a fuse above 800A blowing, you may as well use copper bars. The transformer primary protection usually goes first. But you have to stick to the rules.

 

[mbrooke]

I’ve never known of a fuse above 800A blowing, you may as well use copper bars. The transformer primary protection usually goes first. But you have to stick to the rules.

If coordinated that way.

For me secondary (main LV fuses) protect transformers from secondary overload and short circuits, while primary fuse protection removes a failed transformer from service. My understanding is that medium voltage fuses handle over loads poorly and are really to take care of short circuits.

 

[ron]

Any reason why there is no switch gear option? Switchboard will (should) work just fine for me but still curious why not SWGR.

There are plenty of SWGR options and I use them too, if the client is willing to pay for that more robust option. Again, depending on the short circuit rating, you can get unfused CB's or fused CB's depending on the manufacturers product and how they can get up to 200kA (or even 300kA in some cases). The fused switches are typically SWBDs in my experience. I have not seen fused switch type switchgear (UL 1558)

 

[mbrooke]

Good enough for me. Maybe I'm not looking hard enough, but why do Eaton fused SWBD catalogs stop at 1,200 amps?

 

[ron]

Good enough for me. Maybe I'm not looking hard enough, but why do Eaton fused SWBD catalogs stop at 1,200 amps?

In my experience because then you need to move to the Eaton Pringle bolted pressure contact switches. The Eaton Pow-R-Line C general purpose distribution switchboard Includes circuit breakers or fusible switch main or branch devices up to 5000A. https://www.eaton.com/us/en-us/cata...tems/pow-r-line-c-switchboards.technical.html

 

[mbrooke]

In my experience because then you need to move to the Eaton Pringle bolted pressure contact switches. The Eaton Pow-R-Line C general purpose distribution switchboard Includes circuit breakers or fusible switch main or branch devices up to 5000A. https://www.eaton.com/us/en-us/catal...technical.html

Ok, that makes sense now. It was this that kept throwing me off:

https://www.eaton.com/us/en-us/catal...-switches.html

Are the <1,200 amp switches in the SWBDs the same as the <1,200 amp pringle switches in the power-r-line c's? (if I'm asking it right)

 

[paulengr]

Ok, that makes sense now. It was this that kept throwing me off:

https://www.eaton.com/us/en-us/catal...-switches.html

Are the

I think in general terms panelboards are 1200 A and under while switchboards go up to 5000 A.

In switchgear there is metal clad and metal enclosed. Generally metal clad is breakers and metal enclosed is fuses but you can go both ways with either one. There are lots of advantages with metal enclosed. Metal clad draw out gear is not nearly as robust as claimed in actual use.

 

[mbrooke]

I think in general terms panelboards are 1200 A and under while switchboards go up to 5000 A.

In switchgear there is metal clad and metal enclosed. Generally metal clad is breakers and metal enclosed is fuses but you can go both ways with either one. There are lots of advantages with metal enclosed. Metal clad draw out gear is not nearly as robust as claimed in actual use.

Good info, thanks

 

[ron]

Ok, that makes sense now. It was this that kept throwing me off:

https://www.eaton.com/us/en-us/catal...-switches.html

Are the <1,200 amp switches in the SWBDs the same as the <1,200 amp pringle switches in the power-r-line c's? (if I'm asking it right)

Pringle is a Eaton brand name for a bolted pressure switch. The smaller <1200 fused switches i think are are just regular fused switches.

The terminology of metal clad and metal enclosed is for medium voltage SWGR, not low voltage

 

[mbrooke]

Pringle is a Eaton brand name for a bolted pressure switch. The smaller <1200 fused switches i think are are just regular fused switches.

The terminology of metal clad and metal enclosed is for medium voltage SWGR, not low voltage

Why does a regular switch become a bolted pressure switch over 1,200 amps? What is the duty cycle and FLC interruption of a switch vs a bolted pressure switch? And where does the name come from?