220 Part III vs 220.84

[Rock86]

Been doing apartment load calculations and was curious if anyone sees an issue using 220.84 over going through Part III of 220? I just compared the numbers and if I could save 38% using the method in 220.84.

General Wattage Total:	194,400.0​
1st 3,000 @ 100%	3,000.0​	Table 220.42
3,000 to 120,000 @ 35%	42,000.0​
Greater than 120,000 @25%	18,600.0​
Ranges	192,000.0​	Table 220.61
Ranges Diversified	49,920.0​
Dryers	120,000.0​	Table 220.54
Dryers Diversified	41,400.0​
Dishwashers	33,600.0​	220.53
Dishwashers Diversified	25,200.0​
Water Heaters	120,000.0​
Water Heaters Diversified	90,000.0​
HVAC	288,492.0​
Elevator**	0​
Landlord RCPTS/Lighting	26,000​
LL Electric Heat	0​
Total:	584,612​	watts
Amperage:	1,623​	amps
Phase:	3​
Voltage:	208​

220.84 Method

General Wattage Total:	194,400.0​
Ranges	192,000.0​
Dryers	120,000.0​
Dishwashers	33,600.0​
Water Heaters	120,000.0​
HVAC	288,492.0​
Total @ 100%	948,492.0​
Total @ 36%	341457.1​
Landlord Load	26,000​
Total Load	367457.1​
Amperage	1020.714​

 

[don_resqcapt19]

You use whichever method you want to, as long as the installation meets the restrictions in 220.84(A).

 

[JoeStillman]

I have a spreadsheet that compares 220 Part III vs. Part IV. Part IV wins for everything over about 30 dwelling units. If there is gas to the building, Part III will win for the smaller multi-fams.

 

[Rock86]

I have a spreadsheet that compares 220 Part III vs. Part IV. Part IV wins for everything over about 30 dwelling units. If there is gas to the building, Part III will win for the smaller multi-fams.

I think I am going to build our current spreadsheet that way, thanks.

 

[Rock86]

You use whichever method you want to, as long as the installation meets the restrictions in 220.84(A).

Thanks. Sometimes it doesn't feel right getting two drastically different numbers. Going with the lower number almost feels a litte.... naughty lol