Apartments being fed by (2) 100A 3-pole switches

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Tainted

Tainted

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Location
New York
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Engineer (PE)
I went to a building today and saw almost all apartments being fed by (2) 100A 3-pole switches. Is this even legal? (See picture below for example) Shouldn't the switches be interlocked? This is the first time I'm seeing this weird setup and it threw me off. Usually apartments only have 1 dedicated disconnecting means. Keep in mind almost all apartments only have 1 panel...

Each apartment has a 208V circuit with neutral.

Would it be legal to grab phase A power from the first switch and phase B power from the second switch to feed a single phase 208V panel in the apartment? Could it be that's how it's setup?

switches.PNG
 
It may be set up for 3 phase-- It may as shown below but also can be 3 phase panels in each apt but that's unlikely

AB
BC
AC
AB
BC
ETC
 
Dennis Alwon said:
It may be set up for 3 phase-- It may as shown below but also can be 3 phase panels in each apt but that's unlikely

AB
BC
AC
AB
BC
ETC
Click to expand...
So for example what you mean is:
apartment 12B would use phase A from the first switch, phase B from the second switch?
 
don_resqcapt19 said:
The disconnect must disconnect all conductors of the circuit, so that would not be permitted.
Click to expand...
So that's exactly what I was concerned about. Why would there be 2 switches for each apartment if they need to be disconnected together? It's strange
 
I've seen similar on older apartment buildings where a second feeder was added for loads such as air conditioning,
 
augie47 said:
I've seen similar on older apartment buildings where a second feeder was added for loads such as air conditioning,
Click to expand...
I doubt that's what's happening in this situation... I also asked the super how many times do these fuses blow, he said they blow frequently in the summer

Check out another pic below, 8 apartments on a 3 pole 100A switch??? Am i crazy for thinking this is not right?

switch 2.PNG

Also notice below the switch, the same apartment numbers show up on another switch
 
Tainted said:
So for example what you mean is:
apartment 12B would use phase A from the first switch, phase B from the second switch?
Click to expand...


No--The first switch shown has apts 8B, 9B, 11B, 12B

8B could be connected to A and B phase in that switch
9B could be connected to B and C phase in that same switch
11B could be connected to A and C phase and
12B connected to A and B phase also
 
Dennis Alwon said:
No--The first switch shown has apts 8B, 9B, 11B, 12B

8B could be connected to A and B phase in that switch
9B could be connected to B and C phase in that same switch
11B could be connected to A and C phase and
12B connected to A and B phase also
Click to expand...
I know but I didn’t know why they needed the second switch
 
Is there any other panles between the meter and the switch in Your picture. There may be a three phase feeder tapped going to each single phase meter.

Draw a quick one line.
 
Someone else already said, a bit of experimentation is needed. Either the labels are wrong, or the wiring is. Each subpanel/load should be fed from only one switch on that main distribution board.

Shut off one switch, measure the voltage in the panels of the affected apartments to verify the whole feed to the apartment is off, not just one leg.
 
Since there are so many apts on a 100 amp breaker my guess is that the hvac is on the second breaker. That makes total sense to me.
 
Tainted said:
No, each apartment has their own meter in the basement too
Click to expand...
This does not math up...if each has its own meter, a switch cannot feed more than one apartment....unless the meters are on the load side of the switch, and it would be rare case where the utility would permit that.
 
don_resqcapt19 said:
This does not math up...if each has its own meter, a switch cannot feed more than one apartment....unless the meters are on the load side of the switch, and it would be rare case where the utility would permit that.
Click to expand...
Tulsa Electrician said:
Is there any other panles between the meter and the switch in Your picture. There may be a three phase feeder tapped going to each single phase meter.

Draw a quick one line.
Click to expand...
All the circuits go into this meter bank

0.jpg

There is an additional meter bank at the back side
 
Oh my, you have a little work ahead of you to figure that out.
Thank you for the pic. It does help
I have never seen a set up like that.
I have seen meter bank taped from a feeder. The meters were private not utility. The breakers above throws me for a loop.
Look forward to what you discover.
 
Something is seriously wrong with the way this is marked. These are 100 amp switches. There's no way you can feed four or five or six seven eight apartments from 100 amp switch.
 
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