Load Calc's

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gap

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Gainesville Florida
Hello all,
Sorry it's been many sleeps since I have thought about load calc's. If I have a 10KW resist load on a 240V single phase circuit, that equates to a 20.84A load per phase--correct? The nominal amps are divided equally between each phase...
Cheers,
Scott
 
10KW Single Phase 240 would be 41.7 amps per phase, 3 phase, equally distributed, would be 24 amps per phase
 
41.67A. I'm sorry--I'm MEP and for some reason in Gainesville FL we have been doing alot of 'M' and 'P'. This is the first commercial 'E' job we have got in 7 months.
 
gap said:
Hello all,
Sorry it's been many sleeps since I have thought about load calc's. If I have a 10KW resist load on a 240V single phase circuit, that equates to a 20.84A load per phase--correct? The nominal amps are divided equally between each phase...
Cheers,
Scott
Click to expand...
No. 41.7A on each line (many say phase, but incorrectly).

If you are load balancing using the panel schedule method, the convention is to put half the volt-amperes (VA; not Watts, not amperes; in this case 5kVA assuming a purely resistive load) on each leg (aka line; not phase). This practice assumes a matching load will be placed on each phase.
 
Meaning you don't split the total 240V 1phase VA load by 2 and distribute that between each leg for an Amp load schedule? If a 10KVA load draws 41.7A, would not half of those electrons come from phase A and the other half from B?
 
gap said:
Meaning you don't split the total 240V 1phase VA load by 2 and distribute that between each leg for an Amp load schedule? If a 10KVA load draws 41.7A, would not half of those electrons come from phase A and the other half from B?
Click to expand...
No....
 
gap said:
Meaning you don't split the total 240V 1phase VA load by 2 and distribute that between each leg for an Amp load schedule? If a 10KVA load draws 41.7A, would not half of those electrons come from phase A and the other half from B?
Click to expand...
With a line to line load all of the current goes in through A and out through B and vice versa.
If half the current went into the equipment from each line, where would it go out? :)

Sent from my XT1585 using Tapatalk
 
gap said:
Meaning you don't split the total 240V 1phase VA load by 2 and distribute that between each leg for an Amp load schedule? If a 10KVA load draws 41.7A, would not half of those electrons come from phase A and the other half from B?
Click to expand...
All of the circuit current goes through the connected legs... However, if you are doing a panel schedule and using it to do load balancing, you put half the VA on each leg... ASSUMING you are going to balance the load, e.g. three 10kVA loads connected AB, BC, AC. Your panel schedule columns would be:
ABC
Load155
Load255
Load355
Total101010
 
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