Service Equipment questions

[Grouch1980]

Without nearby OCPD, this cannot be the service disconnect. It would be an auxiliary disconnect,which may not be allowed by code in this configuration.
The downstream conductors would still be service conductors, with all the restrictions on where inside the building they may be run. And each downstream panel would be a service disconnect which has to be grouped with all other service disconnects. And they would have to be rated as suitable for use as service equipment.

The 400 amp and 600 amp fused disconnects, located downstream from this switch, they are about 5 to 10 feet away, all located in the main electrical room. I'm assuming they are not considered 'nearby OCPD's', but rather the actual service switches?

 

[GoldDigger]

The 400 amp and 600 amp fused disconnects, located downstream from this switch, they are about 5 to 10 feet away, all located in the main electrical room. I'm assuming they are not considered 'nearby OCPD's'?

Possibly nearby. This is the sort of thing which is not well defined in the Code and is up to the discretion of the AHJ. It should be uniformly applied by all of the inspectors under that AHJ.

 

[jap]

Thanks!
Just to add to my second question about the service switch… here’s a picture of that switch. Where I circled in red... what is that? is that supposed to be some kind of 'meltable' link? Also, if this service switch has no fuses, is this installation illegal? I'm not touching it anyway, just wanted to know.

View attachment 2561726

This seems odd.

How are you possibly getting 1000 amps worth of power out of this considering the lug and conductor sizes?

The line side lugs look like they were added, the load side lugs look like they're upside down, and, there's not near enough line side conductors to have fed a full 400 and 600 amp disconnect beyond it.


JAP>

 

[petersonra]

This seems odd.

How are you possibly getting 1000 amps worth of power out of this considering the lug and conductor sizes?

The line side lugs look like they were added, the load side lugs look like they're upside down, and, there's not near enough line side conductors to have fed a full 400 and 600 amp disconnect beyond it.


JAP>

I don't see any wires coming out of the bottom of the switch at all.

If the top of the switch is coming from the POCO maybe they installed them. They can do whatever they want as far as wire sizing goes.

 

[tortuga]

This seems odd.

How are you possibly getting 1000 amps worth of power out of this considering the lug and conductor sizes?

The line side lugs look like they were added, the load side lugs look like they're upside down, and, there's not near enough line side conductors to have fed a full 400 and 600 amp disconnect beyond it.


JAP>

Agreed it hard to tell the size of things from the photos but this looks like a 400A disconnect. This also definitely looks 1930's era.
In an old 1937 code handbook they talk about how there were not cartrige fuses over 600 Amps and to achieve a over 600A rating parallel fuses were used or those 'link' or open fuses.

 

[tortuga]

These link fuses from 1939 might be close, but hard to tell.

 

[Grouch1980]

Sorry guys! I’m out and about. When I get back I’ll post more photos showing the line and load side wiring so you can see the full picture

 

[jaggedben]

I also think the thing circled in red is a fuse element. Can't figure what else it could be.

In which case, that switch is the service disconnect.

 

[leepalmer]

Without nearby OCPD, this cannot be the service disconnect woodoku. It would be an auxiliary disconnect,which may not be allowed by code in this configuration.
The downstream conductors would still be service conductors, with all the restrictions on where inside the building they may be run. And each downstream panel would be a service disconnect which has to be grouped with all other service disconnects. And they would have to be rated as suitable for use as service equipment.

Do the fused disconnects (400 amp and 600 amp) farther downstream indicate that this is not a service switch?

 

[Grouch1980]

This is the top / line side of the switch, with 2 sets of wire coming in. and yes, responding to one of the comments, the total of these wires is NOT rated 1000 amps.

 

[Grouch1980]

And this is the bottom / load side of the switch. You'll see a few sets of lugs on the bottom. the double lugs, pointing upwards, go to the 600 amp fused disconnect switch. The single lugs, 2 pointing down and 1 pointing up, go to the 400 amp fused disconnect switch.

 

[Dennis Alwon]

Even if that link is a fused link there seems to be something wrong with this install. If the panels are close they may fall under the tap rule but if not there is an issue.

 

[jaggedben]

Even if that link is a fused link there seems to be something wrong with this install. If the panels are close they may fall under the tap rule but if not there is an issue.

What, exactly, is wrong with it?

I mean, the switch is tremendously obsolete, obviously, and should have been replaced when the conductors were. (The conductors are obviously newer.) And then there's an open question of whether those fusible links match the rating of the service conductors, and how you would prove it one way or the other. But there's nothing wrong with one fused service disconnect feeding taps to two load side fused disconnects.

 

[retirede]

Interesting the way the line side lugs appear to be field-drilled to fit the mounting holes on the buss.

 

[Dennis Alwon]

What, exactly, is wrong with it?

I mean, the switch is tremendously obsolete, obviously, and should have been replaced when the conductors were. (The conductors are obviously newer.) And then there's an open question of whether those fusible links match the rating of the service conductors, and how you would prove it one way or the other. But there's nothing wrong with one fused service disconnect feeding taps to two load side fused disconnects.

If you look at my post I said If the panels are close they may fall under the tap rule. Otherwise there is an issue

 

[jap]

Interesting the way the line side lugs appear to be field-drilled to fit the mounting holes on the buss.

It's odd for sure,,, when push comes to shove,, those bolts connecting the lugs to the buss would actually become the fusible links.

JAP>

 

[jap]

All the fusible links I've ever seen were installed inside a fuse capsule with removable ends where you could change them out if they blew.

I've never seen a fuse link that was installed open like what's shown in the picture.

Interesting for sure.

JAP>

 

[tortuga]

I think we have established thats the service disconnect, and a very old one indeed. If this is in NYC i bet the original service was DC.
So are the incoming wires the service lateral, owned and maintained by the utility? Where is the CT can? before or after this?
I'd get in there with a old tooth brush and see if I could get a number off those fuse links, that and the size of the wires, thats what determines the service size. EDIT if i zoom in on the light blue wire I think I can make out 350 MCM type TW

 

[jap]

I think we have established thats the service disconnect, and a very old one indeed. If this is in NYC i bet the original service was DC.
So are the incoming wires the service lateral, owned and maintained by the utility? Where is the CT can? before or after this?
I'd get in there with a old tooth brush and see if I could get a number off those fuse links, that and the size of the wires, thats what determines the service size. EDIT if i zoom in on the light blue wire I think I can make out 350 MCM type TW

I had the exact same thoughts and have also zoomed in and saw the 350mcm.

We must be related.

JAP>

 

[Grouch1980]

I think we have established thats the service disconnect, and a very old one indeed. If this is in NYC i bet the original service was DC.
So are the incoming wires the service lateral, owned and maintained by the utility? Where is the CT can? before or after this?
I'd get in there with a old tooth brush and see if I could get a number off those fuse links, that and the size of the wires, thats what determines the service size. EDIT if i zoom in on the light blue wire I think I can make out 350 MCM type TW

Yes, this is NYC. The building is served by service lateral conductors, coming in from the underground, owned by Con Edison. once they come into the service point / service end box (the nomenclature by Con Edison), 2 service entrance conductors come out of that service point and into the top / line side of the switch as you see in the picture. On the load side of the switch, where it goes to the 400 and 600 amp fused disconnect switches, each one of those switches has a meter. So the meters / CT's are downstream of this service disconnect.

I'm wondering why this switch is still there, and wasn't replaced by new... as someone said before, the conductors are much newer.