Service Equipment questions

[Grouch1980]

Hey guys,
I have the following 2 questions:

1. I'm sure the answer is yes, but just in case there's a code nuance that i'm unaware of: are you allowed to pull single phase service entrance conductors from a service end box (service end box is the NYC nomenclature for the 'service point') that has 120/208, 3 phase, 4 wire incoming service conductors from the utility? Or are you limited to just pulling 3 phase service entrance conductors from that service point over to your service equipment? I'm reviewing a proposed design that has a mix of 3 phase and 1 phase service entrance conductors tapping from a 3 phase service point.

2. I was at a building today that has a service switch that fed 2 fused disconnect switches downstream. However, I realized as I was writing down my notes that the service switch was unfused. it was an old, old switch (rated 1000 amps), with just the lever and nothing else. I imagine this would still be considered the service switch, even though it's unfused?

 

[LarryFine]

1. Yes.

2. Yes.

 

[Grouch1980]

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.

 

[Dennis Alwon]

I think it could be just a jumper to make the switch non fused. I wouldn't want to change that link if that is what it is.

 

[Grouch1980]

I think it could be just a jumper to make the switch non fused. I wouldn't want to change that link if that is what it is.

Got it. so is this considered an illegal installation (or not per code)? Since a service switch has to be fused.

 

[petersonra]

Got it. so is this considered an illegal installation (or not per code)? Since a service switch has to be fused.

that is not in the code anywhere. In fact the 2020 code specifically encourages this.

 

[Grouch1980]

that is not in the code anywhere. In fact the 2020 code specifically encourages this.

Interesting... did a google search, it sent me to section 230.91 (2008 NEC), I think this applies to this... "The service overcurrent device shall be an integral part of the service disconnecting means or shall be located immediately adjacent thereto". So it doesn't have to be integral to the service switch.

 

[Dennis Alwon]

Got it. so is this considered an illegal installation (or not per code)? Since a service switch has to be fused.

Not necessarily. I assume the service conductors on the load side of the switch are going directly into a service panel. Are there wires connected on the load end of the switch?

 

[Grouch1980]

Not necessarily. I assume the service conductors on the load side of the switch are going directly into a service panel. Are there wires connected on the load end of the switch?

The load side of the switch has 2 sets of wires, each connected to a different set of lugs; one set goes to a downstream 600 amp fused disconnect switch, and the other set goes to a downstream 400 amp fused disconnect switch. Are these load side wires still considered service entrance conductors, rather than feeders, since the service switch doesn't have fuses?

 

[Grouch1980]

Not necessarily. I assume the service conductors on the load side of the switch are going directly into a service panel. Are there wires connected on the load end of the switch?

If the load side conductors of this 1000 amp switch are still considered 'service conductors'.. does that mean the 2 downstream 400 and 600 amp fused disconnect switches are the actual service switches, or is this 1000 amp switch (from the picture above) the actual service switch? I'm a little confused.

 

[tortuga]

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?

View attachment 2561726

I wonder if that is some kind of arc suppressor. The middle one looks like it might have some kinda lettering on it.

 

[petersonra]

I wonder if that is some kind of arc suppressor. The middle one looks like it might have some kinda lettering on it.

Might be a place to put CTs.

 

[LarryFine]

Maybe those are the fuse elements.

 

[tortuga]

See if you can get a make/model off the switch. I dont think I have any old Royal catalogues in my collection but I could check.

 

[hbiss]

Maybe those are the fuse elements.

it was an old, old switch (rated 1000 amps),

Looks about right.

-Hal

 

[Grouch1980]

See if you can get a make/model off the switch. I dont think I have any old Royal catalogues in my collection but I could check.

Unfortunately that's all I have. Only the print that you see on the switch... 1000 amps, Royal, and 250 volts.

 

[tortuga]

If you zoom in really close on the middle element you can see some markings on it might be 3 zeros, so yeah could be as Larry said its a type of 'open' fuse or even an old shunt for metering. I have never seen a open fuse like that.

 

[Grouch1980]

If you zoom in really close on the middle element you can see some markings on it might be 3 zeros, so yeah could be as Larry said its a type of 'open' fuse or even an old shunt for metering. I have never seen a open fuse like that.

I didn't even see that until you mentioned it.

 

[Grouch1980]

Not necessarily. I assume the service conductors on the load side of the switch are going directly into a service panel. Are there wires connected on the load end of the switch?

Sorry, just circling back to this. The load side wires on this switch, are they considered service conductors or feeders? if this switch is a service switch, then they are feeders. But you called them 'service conductors'... so does that imply this is not a service switch, and the service switches are further downstream (the 400 amp and 600 amp fused disconnects)?

 

[GoldDigger]

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.