Wire Reverse between Life and Neutral

  • #26
173
0
Here in the US everything above a certain size is aluminum. Not sure what that size is. I don't think any circuit run in a normal residence is aluminum, they are all copper. At least that's the way it is in my locality.
For instance, the 50 amp range circuit is still copper.
I don't know if Canada is any different, but we have wire as thick as your thumb that is still copper...what a pain to handle though.

Now why can't you connect the ground to the neutral in an electrical outlet if the ground is connected to neutral in the panel anyhow? Is it just bad practice?
 
  • #27
Averagesupernova
Science Advisor
Gold Member
3,601
603
Sorry I hadn't gotten back to this sooner. Canada is usually more strict than the U.S.A. on electrical codes especially concerning grounding. The reason why the ground is made in the service panel instead of sharing the neutral and ground from the outlet back to the panel is because the neutral is a current carrying conductor and there IS the possibility for a voltage to build up between the actual ground (soil, wet floor, water pipes, etc.) around the outlet and the neutral wire. So if the frame of the appliance was bonded to the neutral at the outlet in the case of a slight buildup of voltage on the neutral at the outlet in question then touching the frame of that appliance would give you tingle.
 
  • #28
Danger
Gold Member
9,607
245
Triden, as far as I know it's illegal to use aluminum wiring in any residential building, and probably any building at all. I well remember a few years ago (or a few dozen; I can't tell the difference), when all houses with aluminum wiring had to have it ripped out and replaced with copper. Aluminum has a nasty habit of starting fires.
 
  • #29
173
0
Triden, as far as I know it's illegal to use aluminum wiring in any residential building, and probably any building at all. I well remember a few years ago (or a few dozen; I can't tell the difference), when all houses with aluminum wiring had to have it ripped out and replaced with copper. Aluminum has a nasty habit of starting fires.
I just talked to my father about when he was working as an electrician in the early days. He was saying all the houses were done in aluminum and you had to make darn sure not to knick it or kink it too hard. Luckily none of his houses burned down :biggrin:
 
  • #30
Danger
Gold Member
9,607
245
Damn straight. Most of the fires probably weren't the fault of the electricians, though. Normal flexing through wind movement of the house, or mice playing around, or any other form of disturbance could be enough to generate a fault. I'm not sure, but I think that there was also a contribution from the dialectric decay of aluminum and steel or copper where connections were made to outlets and switches. Your dad can probably tune us all in on that as well. (Sign him up!)
 
  • #31
1
0
IR drop is the issue.

The following is not to be relied on ....

1. A reason that sudden high loads cause a voltage burp
is that the line from a pole transformer to the service
panel can have enough impedance for a significant IR drop.
When the service neutral is in redundant bond to earth
ground near the service drop, that IR delta is reduced.
Ground bond wires carry current flow shared with the
neutral from the pole transformer, assuming that the
pole transformer ground is in place.

2. Outlet neutrals are not good ground returns for a
couple of reasons that I can think of at this time.
A small fault current from hand to hand can be fatal,
so a "redundant" ground wire, with low impedance,
increases the odds of timely fuse or breaker operation,
particularly if the event creating the shock hazard also
damaged the neutral. A surviving ground conductor
can trip a fuse or breaker to avoid a hazard.

Also, a bare or green conductor is less likely to be
disconnected or left unconnected at the service end.
(Outlets without a ground conductor are not hard to fix if
codes allow running a protected wire to a nearby ground.)
 

Related Threads on Wire Reverse between Life and Neutral

Replies
2
Views
5K
  • Last Post
3
Replies
65
Views
13K
  • Last Post
Replies
1
Views
2K
  • Last Post
Replies
4
Views
2K
  • Last Post
2
Replies
25
Views
5K
Replies
18
Views
3K
  • Last Post
3
Replies
55
Views
17K
  • Last Post
Replies
12
Views
2K
Replies
3
Views
2K
Replies
5
Views
4K
Top