Con Edison Service End Box Needed

[Tainted]

There is a 60 unit apartment building with a really old service end box which needs replacement. The building has 120/208V 3-phase 4-wire. Con-Edison came back to me and said existing service is adequate and that there are existing 4 sets of 4#500KCMILS conductors coming into the building:


I am looking for a specification and drawing number in Con-Edison bluebook that can support 4 sets of 4#500KCMILS incoming service conductors but I cannot find it. I only see service end boxes that can support up to 3 sets of 500KCMILS incoming service conductors:

 

[Todd0x1]

Maybe see if that All City switchboard can make you one, and check with con-ed if they'll allow it. I have a feeling they would be quicker to approve something not in the book from one of those little local switchboard mfgrs vs from one of the majors.

 

[Tainted]

Maybe see if that All City switchboard can make you one, and check with con-ed if they'll allow it. I have a feeling they would be quicker to approve something not in the book from one of those little local switchboard mfgrs vs from one of the majors.

I am a little bit shocked Con-Edison is saying there are 4 sets of 500s coming into the building for a 60 unit apartment building... usually it should be 2 sets. Maybe it's a mistake?

 

[Todd0x1]

I am a little bit shocked Con-Edison is saying there are 4 sets of 500s coming into the building for a 60 unit apartment building... usually it should be 2 sets. Maybe it's a mistake?

Who knows....maybe there's 4x 500s and not 4 sets of 4.....If this is that one with 60x 50 amp services I could almost see single 500s given the demand factor for 60 units plus how the utility likes to undersize their service conductors....(not an engineer that's all speculation)

 

[Tainted]

Who knows....maybe there's 4x 500s and not 4 sets of 4.....If this is that one with 60x 50 amp services I could almost see single 500s given the demand factor for 60 units plus how the utility likes to undersize their service conductors....(not an engineer that's all speculation)

what does 4--4-500 mean to you? I think it means 4 500s per phase

 

[Todd0x1]

what does 4--4-500 mean to you? I think it means 4 500s per phase

I would agree

 

[infinity]

I am a little bit shocked Con-Edison is saying there are 4 sets of 500s coming into the building for a 60 unit apartment building... usually it should be 2 sets. Maybe it's a mistake?

Two sets of 500's is less than 800 amps. Let's say it is 800 amps 800/60= 13.3 amps per apartment. I'm not seeing how 2 sets would work. Even 4 sets is only 25.6 amps per apartment.

 

[Tainted]

Two sets of 500's is less than 800 amps. Let's say it is 800 amps 800/60= 13.3 amps per apartment. I'm not seeing how 2 sets would work. Even 4 sets is only 25.6 amps per apartment.

I remember speaking with Con-Edison about a different building with similar number of units and they said 2 sets of 500s copper were adequate. I asked them how much capacity does the building have, they told me it was an unusual question but I was just curious and they "unofficially" told me it's 1150 amps. Not sure how they got that number, maybe the way the coppers are insulated and trenched counts for the extra amps?

 

[Todd0x1]

Two sets of 500's is less than 800 amps. Let's say it is 800 amps 800/60= 13.3 amps per apartment. I'm not seeing how 2 sets would work. Even 4 sets is only 25.6 amps per apartment.

But don't you get a demand factor of 24% for 60 units? So ignoring an actual load calc and just going off 50 amps, on a 3ph service with 2 hots to each apt 60x50x2 = 6000/3=2000 per phase *.24 = 480a per phase then add utility company "2ga aluminum is good for 400 amps" factor and I could see them using a single set of 500s. Or do I have this all wrong?

Now I wonder if 4--4-500 means a 4 inch pipe with 4x 500?

 

[Tainted]

But don't you get a demand factor of 24% for 60 units? So ignoring an actual load calc and just going off 50 amps, on a 3ph service with 2 hots to each apt 60x50x2 = 6000/3=2000 per phase *.24 = 480a per phase then add utility company "2ga aluminum is good for 400 amps" factor and I could see them using a single set of 500s. Or do I have this all wrong?

Now I wonder if 4--4-500 means a 4 inch pipe with 4x 500?

Don't forget house loads. Regardless, Con-Edison could care less about the NEC demand factors

 

[infinity]

If they're saying that the existing conductors are adequate then what is the issue?

 

[Tainted]

If they're saying that the existing conductors are adequate then what is the issue?

The issue is I need to replace existing service end box that can take 4 sets of incoming Con-Edison feeders. I only see a copper detail service end box for 3 sets but not 4 sets... Con-Edison dwg number EO-9073B

If there were less than 4 sets coming into the building I would have no issue.

 

[Hv&Lv]

Two sets of 500's is less than 800 amps. Let's say it is 800 amps 800/60= 13.3 amps per apartment. I'm not seeing how 2 sets would work. Even 4 sets is only 25.6 amps per apartment.

But thats with no diversity. The NEC gives a demand factor, and utilities use ~60% diversity on that many apartments
Wofford is 467 amps. There is no NEC de-rating on utility wires.

Im assuming aluminum coming in from the utility