Down sizing the Grounded Conductor

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elmundogrande

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With harmonics and transient voltage what the are and we hear of up sizing the grounded conductor on home runs why does the code still allow for down sizing the the grounded wire, I know that the reason was to save money because the neutral only carries the unbalance load, and if careful balancing by the J wireman it should be low amps. Why take the risk with todays high use of electronics from lighting to CPU's.
 
If you are doing a 200 ampere service for a small, total electric home why would you need a full sized neutral? About ? the load will be straight electric heat and water heating. The rest would be for general service where the range and dryer both use just 70% for the neutral. Tell me why you couldn't use a #4 Cu. neutral since harmonics are not big in dwelling units?

You can repeat this type of process with a multitude of services or feeders to get a reduced neutral. :)
 
elmundogrande said:
With harmonics and transient voltage what the are and we hear of up sizing the grounded conductor on home runs why does the code still allow for down sizing the the grounded wire, I know that the reason was to save money because the neutral only carries the unbalance load, and if careful balancing by the J wireman it should be low amps. Why take the risk with todays high use of electronics from lighting to CPU's.
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I never run a full size neutral to a dwelling. For a 200amp service I usually pull 1/0 copper which is way more than necessary. As Charlie said no harmonics- or not many -- in a home. Even if the house is not totally electric 1/0 is oversized. So it depends on your perspective. It is oversized but not larger than the ungrounded conductors.
 
charlie said:
If you are doing a 200 ampere service for a small, total electric home why would you need a full sized neutral? About ? the load will be straight electric heat and water heating. The rest would be for general service where the range and dryer both use just 70% for the neutral. Tell me why you couldn't use a #4 Cu. neutral since harmonics are not big in dwelling units?

You can repeat this type of process with a multitude of services or feeders to get a reduced neutral. :)
Click to expand...

Totally agree on a normal house, neutral already far bigger than ever needed
 
The harmonic current is not additive on a single phase system like it is on a three phase system so that cannot be used as a reason not to downsize.
 
elmundogrande said:
With harmonics and transient voltage what the are and we hear of up sizing the grounded conductor on home runs why does the code still allow for down sizing the the grounded wire, I know that the reason was to save money because the neutral only carries the unbalance load, and if careful balancing by the J wireman it should be low amps. Why take the risk with todays high use of electronics from lighting to CPU's.
Click to expand...

How about in commercial I know not a factor in Dwelling. Say you wire a mini-mall and down size the Neutral for a liquor store they move out and make it cyber cafe/ hair salon
 
elmundogrande said:
How about in commercial I know not a factor in Dwelling. Say you wire a mini-mall and down size the Neutral for a liquor store they move out and make it cyber cafe/ hair salon
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What if they do?

Any electrician adding loads to an existing panel should be looking at the existing conditions before moving forward.
 
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