50AMP/1PH/208V Service for Apartment

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Electricalhelp

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How do you show an load calculation for an existing apartment (Studio) having a 50AMP/1PH/208V service with the following equipment installed in an apartment before.

The apartment has the following
- Fridge (1000W)
-Dishwasher (500W)
- Hood/Microwave (1000W)
- Gas Oven (100W)
- 4 Kitchen Receptacles (2X1500W=3000W)
- Bathroom Receptacle (180W)
- Bathroom Fan (100W)
- 14 General Receptacles (14*180=2520W)
- HVAC Split System. 20AMP/1PH for Condenser and 120V/1P/20AMP for Air Handler (10A*208V=2080W and 10A*120V=1200W)
- 30 Recessed Light at 4W each. (30*4W=120W)

Total Watt = 11,800W
Total Amp = 11,800W / 208V = 56.73A
 
I didn’t think a 50 amp service was even allowed for an apartment. 230 says 100.
Or is this a test question..
 
electrofelon said:
HV,. I think you are thinking of the hundred amp minimum requirement for services to one family dwellings. That would not apply here.
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Sort of depends, but yes most the time with a 208/120 supply and multifamily you typically are supplying individual dwelling units with a 208/120 single phase feeder, so nothing in art 230 applies to this feeder.
 
electrofelon said:
HV,. I think you are thinking of the hundred amp minimum requirement for services to one family dwellings. That would not apply here.
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Ok. But... An apartment with a separate service for this apartment isn’t a single family dwelling?
Not quite getting it
The op said service, not feeder
 
Hv&Lv said:
Ok. But... An apartment with a separate service for this apartment isn’t a single family dwelling?
Not quite getting it
The op said service, not feeder
Click to expand...
See art 100 definitions of dwelling. Unless it is a stand alone building it likely is not a single family dwelling.
 
Disagree with kwired here. The definition for "dwelling, one family", uses building*, not structure, so firewalls play in. A four-plex with firewalls between units and no interior common space seems like one structure but four buildings, and would have four single-family dwelling units (like a strip mall).

*"Building. A structure that stands alone or that is separated from adjoining structures by firewalls. " (2017)

AFAICT, whether it gets a service or feeders only depends on how it was wired, not single/multi dwelling status.
 
zbang said:
Disagree with kwired here. The definition for "dwelling, one family", uses building*, not structure, so firewalls play in. A four-plex with firewalls between units and no interior common space seems like one structure but four buildings, and would have four single-family dwelling units (like a strip mall).

*"Building. A structure that stands alone or that is separated from adjoining structures by firewalls. " (2017)

AFAICT, whether it gets a service or feeders only depends on how it was wired, not single/multi dwelling status.
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yes and art 230 does allow separate services to each occupant in multioccupancy buildings.

NEC doesn't really mention firewalls when determining what is separate either. Most the time in multi occupant situations building codes will require them anyway.

A 30 unit apt building (random number don't read anything into that number) will typically have at least one hour wall between all units, maybe a two hour wall between certain number "groups" of units.

Bottom line is I think there is more options on how to supply most multi occupant situations than many realize.
 
Electricalhelp said:
How do you show an load calculation for an existing apartment (Studio) having a 50AMP/1PH/208V service with the following equipment installed in an apartment before.

The apartment has the following
- Fridge (1000W)
-Dishwasher (500W)
- Hood/Microwave (1000W)
- Gas Oven (100W)
- 4 Kitchen Receptacles (2X1500W=3000W)
- Bathroom Receptacle (180W)
- Bathroom Fan (100W)
- 14 General Receptacles (14*180=2520W)
- HVAC Split System. 20AMP/1PH for Condenser and 120V/1P/20AMP for Air Handler (10A*208V=2080W and 10A*120V=1200W)
- 30 Recessed Light at 4W each. (30*4W=120W)

Total Watt = 11,800W
Total Amp = 11,800W / 208V = 56.73A
Click to expand...

In all respect.. * if this being a test question, it's the "worst-worded" test question, that I've ever seen. (50amp/1phase 208V service?) Sounds like a feeder to me.
*Studio Apartment where, possibly over a garage or a building loft ?
In any possibilities in using 220.83 (A) & (B).. existing dwelling unit, it's requiring a square footage..

Information provided in above posting is lacking.
 
Dell3c said:
In all respect.. * if this being a test question, it's the "worst-worded" test question, that I've ever seen.
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Actually we don't know if that is the actual wording.

Roger
 
Hv&Lv said:
Ok. But... An apartment with a separate service for this apartment isn’t a single family dwelling?
Not quite getting it
The op said service, not feeder
Click to expand...
I was curious how the feeder size was only 50AMP. But I was wondering how to calculate the service to be only 50 AMP.

Also this is a multi story building with a much of apartments. But the owner is knockings down the bedroom walls to make it a studio apartment.

But when I opened up the panel, I saw a 1/0 wire coming in and there was only a 50AMP main breaker on the panel. This was a another question for a later time I need to figure out.
 
Electricalhelp said:
I was curious how the feeder size was only 50AMP. But I was wondering how to calculate the service to be only 50 AMP.

Also this is a multi story building with a much of apartments. But the owner is knockings down the bedroom walls to make it a studio apartment.

But when I opened up the panel, I saw a 1/0 wire coming in and there was only a 50AMP main breaker on the panel. This was a another question for a later time I need to figure out.
Click to expand...
There is no minimum feeder size that must always be used. If you had very basic unit with only the 2 required SABC's and only say a couple hundred square feet that means you only need 3600 VA total. Divide that by 120 and you could put this on a 30 amp 120 volt feeder.
 
Dell3c said:
In all respect.. * if this being a test question, it's the "worst-worded" test question, that I've ever seen. (50amp/1phase 208V service?) Sounds like a feeder to me.
*Studio Apartment where, possibly over a garage or a building loft ?
In any possibilities in using 220.83 (A) & (B).. existing dwelling unit, it's requiring a square footage..

Information provided in above posting is lacking.
Click to expand...

There is only a PTAC unit now and the rest reminds the same but they added a wine cooler


The apartment has the following
- Fridge (1000W)
-Dishwasher (500W)
- Hood/Microwave (1000W)
- Gas Oven (100W)
- 4 Kitchen Receptacles (2X1500W=3000W)
- Bathroom Receptacle (180W)
- Bathroom Fan (100W)
- 14 General Receptacles (14*180=2520W)
- HVAC (10A*208V=2080W)
- 30 Recessed Light at 4W each. (30*4W=120W)
-Wine Cooler (840W)

Just want to verify if I did the calculation correctly.

For the small appliance, I did the minimum of 2. So I was including the Fridge and Microwave. There are 4 additional Kitchen Receptacle, but assumed that's included in the general receptacles total.
NEC 220.83.png


 
Since this is 208/120, I believe you should take the 120 volt loads and calculate them as though it was a 240/120 service, and then add in the 208 volt loads.
 
Barbqranch said:
Since this is 208/120, I believe you should take the 120 volt loads and calculate them as though it was a 240/120 service, and then add in the 208 volt loads.
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Sorry but I'm a little confused since, the Article 220.83 states "120/240-volt or 208Y/120-volt"

Can you show me an example or two
 
Electricalhelp said:
For the small appliance, I did the minimum of 2. So I was including the Fridge and Microwave. There are 4 additional Kitchen Receptacle, but assumed that's included in the general receptacles total.
Click to expand...

Not that it would make a difference, but you would need to include the Microwave/Hood and Bathroom fan in your calculation.

It looks to me as if the Standard Calculation would result in a lower calcuation.
 
That 1000 VA fridge and 840 VA wine cooler may draw that for like 5 minutes when in defrost. But otherwise probably draw much less in normal run mode.
 
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