NEC Example D1b

[es1451]

25% of the largest motor which is 12A is 3A so line A is 3A, and the neutral is 3A
On line B it is 2A. Line B is 25% of what motor or appliance ???

 

[jumper]

The disposer. 25% of 8 amps is 2 amps.

 

[es1451]

Example D1b

Example D1b

Thanks you very much.... Jumper

 

[jumper]

You are a welcome;however, the credit belongs to mivey. He did the leg work. I only answered, because I had read his response to your earlier post and knew the answer.

 

[es1451]

Example D1b

Example D1b

Thanks Mivey for your help.... es1451

 

[mivey]

Thanks Mivey for your help.... es1451

My pleasure (I'm staying at a Ritz and if I have heard that once from staff, I've heard it a thousand times).:smile:


add: You could always "bump" your previous thread: http://forums.mikeholt.com/showthread.php?p=1031443 if no one has answered in a while. No need to start a new thread and it will keep someone from re-answering in the original thread. You can "bump" by posting a reply like "bump". You may not always get a fast reply as many of us get busy. I have been stuck in a conference all day.

Good luck with your studies and let us know if we can help again.:smile:

 

[steve66]

The disposer. 25% of 8 amps is 2 amps.

So why do we add 25% for a motor load to the AC unit, and not 25% to the dishwasher? I would have considered both of those appliances.

Is it because the AC unit is almost all compressor load, while the dishwasher is mostly a heating element?

Steve

 

[es1451]

Example D1b

Example D1b

Thanks steve 66 . The knowledge of this example has come full circle. Others in my class did not completely understand this. I told them I know where to get the right answer and
more...thanks to all that shared !!! es1451

 

[jumper]

So why do we add 25% for a motor load to the AC unit, and not 25% to the dishwasher? I would have considered both of those appliances.

Is it because the AC unit is almost all compressor load, while the dishwasher is mostly a heating element?

Steve

The A/C is the largest load on Line A and the disposer is the largest load on Line B You are correct that the load of a dishwasher is split between the element and the motor, around 60/40 I believe. 430.34 says 125% plus the sum of the others. Since there is no large 240 volt motor, it is the largest motor on each line, A/C on A and disposer on B at 125% and all others, dishwasher etc, at 100%. I hope I made sense.