Table 220.55, Multi dwelling calculation NEC example

[de2]

NEC Annex D Example D4(b)- Multi Family Standard Calculation

There are 20 unit and each unit has electrical range, rated 8,000VA. In the example calculation is 20x8,000= 160,000

So Table 220.55 is not applied here. Can the reason of this be this table is for "Single Family Dwelling" .

If a single family dwelling had 20 ranges with each 8,000 VA, than 28% from table would have been applied.

Table 220.55 CAN NOT BE USED for Multi-Family dwelling feeder calculation, Agree?

 

[david luchini]

Table 220.55 CAN NOT BE USED for Multi-Family dwelling feeder calculation, Agree?

No. Table 220.55 can be used be used for multi-family dwellings.

It's not used in Example D4(b) because they use the optional calculation in 220.84 in that example, rather than the standard calculation.

Look at Example D4(a), they use the standard calculation (and Table 220.55) for multiple dwellings in that example.

 

[david]

Edit

 

[de2]

No. Table 220.55 can be used be used for multi-family dwellings.

It's not used in Example D4(b) because they use the optional calculation in 220.84 in that example, rather than the standard calculation.

Look at Example D4(a), they use the standard calculation (and Table 220.55) for multiple dwellings in that example.

I typed my question wring;
Table 220.55 Can Not Be used for Optional Method Multi Dwelling Calculation, agree?

 

[david luchini]

I typed my question wring;
Table 220.55 Can Not Be used for Optional Method Multi Dwelling Calculation, agree?

If you do the optional calculation in 220.84, you have to calculate the load the way it tells you too. You can't pick sections of the standard calculation and insert them into the optional calculation.

 

[de2]

If you do the optional calculation in 220.84, you have to calculate the load the way it tells you too. You can't pick sections of the standard calculation and insert them into the optional calculation.

Table 220.55 is located at Part III, which is standard calculation. Therefore my statement is correct, you can not use table 220.55 to do optional calculation.