Service load calculation

[Cdawg406]

Hey all, I have a service load calculation for a 4 plex apartment complex that is being remodeled. A previous EC was let go from the project at about 75% completion. The building has an existing 400 amp meter pack. The owner of the building has requested a load calculation from multiple EC's and other contractors have stated the service to be undersized and needs to be upgraded to 600 amps. I have found that we meet all the requirements to use the optional load calculation 220.84. All loads in the building are electric. Each unit is identical and there are no house loads. I feel confident in my calculation unless I'm misinterpreting the code. Any insight would be greatly appreciated!

General load Count VA Total
General lighting load 3,080 ft2 3 VA 9,240 VA
Small appliance circuits 8 1,500 VA 12,000 VA
Laundry circuits 4 1,500 VA 6,000 VA

Heating load Count VA Total
Electric space heater - 2,000 W (8.3A at 240V) 20 2,000 VA 40,000 VA

Other load Count VA Total
Bath / laundry fan - 50 W (0.4A at 120V) 4 50 VA 200 VA
Dishwasher - 1,200 W (10A at 120V) 4 1,200 VA 4,800 VA
Dryer - 5,000 W (20.8A at 240V) 4 5,000 VA 20,000 VA
Microwave - 1,200 W (10A at 120V) 4 1,200 VA 4,800 VA
Range / Oven (Electric) - 12,000 W (50A at 240V) 4 12,000 VA 48,000 VA
Refrigerator - 900 W (7.5A at 120V) 4 900 VA 3,600 VA
Water heater (Electric) - 5,500 W (22.9A at 240V) 4 5,500 VA 22,000 VA

Final calculation
General load 27,240 VA
Other load 103,400 VA
HVAC load 40,000 VA
Total calculated load for 4 units at 45% per 220.84 76,788 VA
Calculated amperage (load / 240V) 320 A

 

[augie47]

If you missed it, I did also
same number

 

[suemarkp]

You can trim the numbers even more. Is the refrigerator on its own circuit or on a small kitchen small appliance circuit? If on a small appliance circuit, the 1500VA for those covers the fridge. Also, motors less than 1/8 HP can be included in the 3VA/sq ft number, so bath fans most likely don't need to be counted.

 

[Cdawg406]

You can trim the numbers even more. Is the refrigerator on its own circuit or on a small kitchen small appliance circuit? If on a small appliance circuit, the 1500VA for those covers the fridge. Also, motors less than 1/8 HP can be included in the 3VA/sq ft number, so bath fans most likely don't need to be counted.

This is very helpful. the fridges will be on their own circuits. I wanted to add the bath fans to be safe because they are already installed and everything is sheetrocked. There is worry that along with the service, feeders and panels need to be replaced but I don’t think this is necessary.

 

[tortuga]

Also, motors less than 1/8 HP can be included in the 3VA/sq ft number, so bath fans most likely don't need to be counted.

While thats the case in the 220.40 calc (220.41) that does not apply in part IV Optional calcs that I am aware of.
Not that it makes a difference

 

[augie47]

You can debate over a few amps one way or another but your calculations show the existing 400 amp service is adequate which appears to be the question at hand.