Voltage Size of Residential Building

[NEC User]

For a New York City Residential building, my understanding is Con Edison will provide either 120V/240V single phase service or 208Y/120V three phase service. I'm not sure of the Hz but, since it's America I presume 60Hz.

The mechanical designer submitted plans show most of the equipment rated for 208/230/1/60 and one rated for 220/240/1/50. I am not familiar with this notation. I think it means it will operate with 208V through 230V and the second will operate with 220V through 240V. I understand they are both single phase with the first one operating at 60 Hz and the second at 50Hz.
There aren't any 3 phase loads so it doesn't make sense for me to request 208Y/120V from Con Edison.

My questions are as follows:
What voltage should I request from Con Edison for this residential building? 120/240 single phase?
What does 208/230 mean?
What does 220/240 mean?
Should I tell the mechanical designer that he needs to revise his design to utilize only equipment that operates using 60Hz and either 120V or 240V?

 

[infinity]

The 220/240 is irrelevant since that pertains only to 50 Hz. So your next question is 1? or 3?? That would depend on your loads. If there are almost no anticipated 3? loads then you might be better off with 1?. Also the total connected load would need to be considered. Typically the POCO will limit how much 1? load they will allow before they require 3?.

 

[Jraef]

...
My questions are as follows:
What voltage should I request from Con Edison for this residential building? 120/240 single phase?

How big of a service is it?​

What does 208/230 mean?

It means what you thought; 208 through 230V is fine.​

What does 220/240 mean?

Same thing, 220 through 240 is fine.​

Should I tell the mechanical designer that he needs to revise his design to utilize only equipment that operates using 60Hz and either 120V or 240V?

Depends on what it is. If it has an AC motor in it, I would insist on 60Hz machinery. If it's a heater, doesn't matter. No reason to go with 120V however.​

Better advice: hire a qualified electrician.

 

[SMHarman]

If you ever want to install an electric dryer you need a 3ph.
Whatever Work you are doing needs a licenced electrician to do it and pass building inspection.

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[Little Bill]

If you ever want to install an electric dryer you need a 3ph.
Whatever Work you are doing needs a licenced electrician to do it and pass building inspection.

Sent from my LT26i using Tapatalk

Why would need 3-ph for a dryer unless the dryer is 3-ph?:?

 

[darekelec]

Taken from ConEd blue book page 11
5. CHARACTERISTIC OF ELECTRIC SERVICE

Standard service is derived directly from the standard system of distribution and
comprises: Three phase, four wire, 120/208-volt service; or single-phase, two
wire, 120-volt service; or three wire, 120/208-volt service, comprising two
conductors and the neutral of the three-phase, four wire system.

So I will never be able to use Table 310.15(B)(6) in 2008

You can PM me if you need some work to be done.

 

[darekelec]

And power company bumps up the voltage often to 217V or 220V which made me confused in the past (and explained on this forum), but it's still nominal 208V

 

[NEC User]

It's a 5 story residential building for only 2 tenants. I think 120/240 single phase is appropriate. I will check with con edison. If so, does that mean the equipment rated for 208/230/1/60 can not operate from this service?

 

[GoldDigger]

Equipment rated for 208/230 can be used with either 240 single phase or 208 three phase (line to line) but may produce less heat or mechanical force at 208.
The equipment rated only for 120/240 may or may not work properly off 208 three phase.
Equipment rated for 240/50Hz may run fast or not operate correctly on 60 Hz.

Tapatalk!

 

[iwire]

It's a 5 story residential building for only 2 tenants. I think 120/240 single phase is appropriate. I will check with con edison. If so, does that mean the equipment rated for 208/230/1/60 can not operate from this service?

The first question they will ask you will be what is the calculated load.

So do you know the calculated load for this project? As was mentioned if the load is significant they will not provide a single phase service.

 

[NEC User]

I want to recommend a proper/efficient design. Regarding the equipment rated for 208/230/1/60, which means 208-230 volts using single phase at 60 Hz:

• The comment above says it can be used with 240V single phase but may produce less heat or mechanical force. 240V is not within the 208-230 volt range so shouldn't a different piece of equipment be specified?
• The comment above says it can be used with 208V line to line for single phase but may produce less heat or mechanical force. 208V is within the range so shouldn't it operate correctly?
• If the equipment is rated at 208/230/1/60 but using 240V single phase and 208 line-to-line may produce less heat or mechanical force. Then what voltage supply was the equipment supposed to be supplied with under ideal conditions?

 

[petersonra]

I don't mean to pick on you, but based on your comments in this thread so far, it appears to me that it might be best to have someone more familiar with these issues advising the building owner on what is appropriate.

 

[SMHarman]

Why would need 3-ph for a dryer unless the dryer is 3-ph?:?

Taken from ConEd blue book page 11
5. CHARACTERISTIC OF ELECTRIC SERVICE

Standard service is derived directly from the standard system of distribution and
comprises: Three phase, four wire, 120/208-volt service; or single-phase, two
wire, 120-volt service; or three wire, 120/208-volt service, comprising two
conductors and the neutral of the three-phase, four wire system.

So I will never be able to use Table 310.15(B)(6) in 2008

You can PM me if you need some work to be done.

Because how else do you get the 208v? 30a receptacle?

And that will make a massive dent in the load on a single phase.

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[Little Bill]

Because how else do you get the 208v? 30a receptacle?

And that will make a massive dent in the load on a single phase.

Sent from my LT26i using Tapatalk

Standard service is derived directly from the standard system of distribution and
comprises: Three phase, four wire, 120/208-volt service; or single-phase, two
wire, 120-volt service; or three wire, 120/208-volt service, comprising two
conductors and the neutral of the three-phase, four wire system.

Just because the service is 3? doesn't mean all the equipment has to be 3?. You can use single ? 208V or 240V for equipment.

Also, the part in red, says the POCO could just bring single ? from the 3? supply into the building.

 

[SMHarman]

I know.
But if you spec single phase, two wire 120v as the OP indicated you can never add a 208v Electrical outlet in the unit.
Being as in NYC a condenser dryer is often the only one you can install due to building preservation code and bathrooms and kitchens in internal spaces that is severely limiting.
Just sayin if I were speccing this I would get the service you highlight in red to futureproof not the one before that.

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[Little Bill]

You didn't mention anything other than what you stated below.

If you ever want to install an electric dryer you need a 3ph.
Whatever Work you are doing needs a licenced electrician to do it and pass building inspection.

Sent from my LT26i using Tapatalk

That's why I asked this

Why would need 3-ph for a dryer unless the dryer is 3-ph?:?

Because how else do you get the 208v? 30a receptacle?

And that will make a massive dent in the load on a single phase.



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You can get the 208V from the two ungrounded and neutral that Con Ed said they could bring in from the 4-wire service.

I know.
But if you spec single phase, two wire 120v as the OP indicated you can never add a 208v Electrical outlet in the unit.
Being as in NYC a condenser dryer is often the only one you can install due to building preservation code and bathrooms and kitchens in internal spaces that is severely limiting.
Just sayin if I were speccing this I would get the service you highlight in red to futureproof not the one before that.

Sent from my LT26i using Tapatalk

I don't see where the OP said 120V single ?. He said 120/240V single ?. Con Ed's sheet said they could provide 2-wire 120V, but I don't see where the OP said that.

May be just miscommunication, but I just didn't understand why you said in order to have an electric dryer, you needed a 3? service.

 

[SMHarman]

In the first question of the last para of the OP is where he goes all 120 single phase.

He has 3 options from con Ed. The most prevelant and handy imho is the third. One is overkill for most residential. Two is limiting.

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[mbrooke]

If you can get 120/240 I recommend it. 208 volts has no advantage in a residence. Only reason why Con ed offers 120/208 are because of large apartments that might have 3 phase pumps and elevator motors.


208/230 means that your equipment will run on either 208 or 240 volts. 240 volts being supplied to 230 ot equipment will not mean a thing since its still within range. The IEC simply harmonized 220 and 240 to 230 since 230 will work on 220 and 240. In the NEC 230 volts is along the same lines, its a nominal voltage which means a little higher or lower will not harm the appliance. All appliances are made to work on plus or minus the specified value.


Only issue however may be running 50hz equipment on 60. Hair dryers and heating equipment will not care as well as light bulbs, but some appliances with motors will run to fast. Microwave ovens will not work on a different frequency. They do offer 60hz 230 volt equipment if needed as well as 120volt 60hz which is readily available in the states. An American supply is designed to handle both 120 and 240, so local appliances can be used without worry.