Con Ed requirement

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binwork91

Senior Member
Location
new york
Occupation
electrical engineer
Someone told me that NY Con Edison requires the same number of sets of conductors on the line side and the load side of the meter.


However, I cannot find any code or Con Edison document that mentions this requirement.


Has anyone heard about this?
 
It is not the case, because the conductors on the utility side of the meter are chosen by Con Ed based on their standards, and on the load side they are based on the NEC, which are typically larger (lower ampacity).
 
ron said:
It is not the case, because the conductors on the utility side of the meter are chosen by Con Ed based on their standards, and on the load side they are based on the NEC, which are typically larger (lower ampacity).
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No, I mean in the building, in the main electrical room. For example, if three sets of 600 kcmil copper conductors are connected to the line side of a 1200 A CT, you must also use three sets of 600 kcmil copper conductors on the load side. You cannot use four sets of 350 kcmil copper.

I don’t know if this is a Con Edison requirement or if it depends on the Con Edison inspector
 
I don’t believe this to be true. I did a building with a 208 volt service 4000 amps with 11 sets coming from CT cabinet to the main. Con Ed had 10 sets to be true
 
binwork91 said:
Someone told me that NY Con Edison requires the same number of sets of conductors on the line side and the load side of the meter.


However, I cannot find any code or Con Edison document that mentions this requirement.


Has anyone heard about this?
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I once asked Con-Ed if I can use 3-phase meter to feed a single phase load, he said no so I guess it's true, but not sure if it's anywhere in writing

For context I told him if I can feed an apartment unit with a 3-phase meter in case the apartment wants to upgrade to a 3-phase panel in the future.
 
binwork91 said:
No, I mean in the building, in the main electrical room. For example, if three sets of 600 kcmil copper conductors are connected to the line side of a 1200 A CT, you must also use three sets of 600 kcmil copper conductors on the load side. You cannot use four sets of 350 kcmil copper.

I don’t know if this is a Con Edison requirement or if it depends on the Con Edison inspector
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Oh just read this, I don't think this is true. Otherwise how are you able to get away with fire alarm or any other taps on load side of CT? (unless you have a separate meter but it's usually done on load side of CT)
 
Tainted said:
I once asked Con-Ed if I can use 3-phase meter to feed a single phase load, he said no so I guess it's true, but not sure if it's anywhere in writing

For context I told him if I can feed an apartment unit with a 3-phase meter in case the apartment wants to upgrade to a 3-phase panel in the future.
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But a lot of fire alarms are single-phase and are fed from the load side of a three-phase C.T.

Tainted said:
Oh just read this, I don't think this is true. Otherwise how are you able to get away with fire alarm or any other taps on load side of CT? (unless you have a separate meter but it's usually done on load side of CT)
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I agree, but I’m a bit worried whether this has been documented somewhere, and if I miss it, fixing the issue later could be very costly.
 
binwork91 said:
But a lot of fire alarms are single-phase and are fed from the load side of a three-phase C.T.
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Yea but the primary load on the CT is usually 3-phase load.

What I am trying to say is if you tell Con-Ed you want a 4-wire meter on a 3-wire apartment unit, they will not give it to you. I asked Con-Ed to give us 4-wire meters in case the apartment wants to be 3-phase in the future and they said no.

Also see Con-Ed bluebook page 30:

"While the preferred place for service taps or additional meters is in the service end box, it is permissible for them to be made in other locations such as the troughing between the service end box and the meter equipment and on the line side of the service switch if the lugs are designed for double lugging."

It's saying you can tap on load side of CT (meter equipment), meaning that you don't need the same sets of conductors on the line and load of the CT
 
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