LeftieBiker
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Re: Breaker thrown. I wonder what root source of problem was?

Mon May 10, 2021 12:28 pm

As I wrote, you can't always tell the exact nature of a hidden problem just by looking at one photo of it. The electrician obviously used a big pair of linesman's pliers (or something similar) and he crushed that wire in multiple places, to the point of causing part of it to crumble. I wouldn't use that electrician again. I've seen all sorts of serious mistakes in rewiring large parts of my house, but never that one.
Brilliant Silver 2021 Leaf SV40 W/ Pro Pilot & Protection
2009 Vectrix VX-1 W/18 Leaf modules, & 2 lithium E-bicycles.
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PLEASE don't PM me with Leaf questions. Just post in the topic that seems most appropriate.

SageBrush
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Re: Breaker thrown. I wonder what root source of problem was?

Tue May 11, 2021 5:06 am

LeftieBiker wrote:
Mon May 10, 2021 12:28 pm
I wouldn't use that electrician again.
Indeed. So much for 'hiring a pro.'
The use of Alu wire was a fat hint that the electrician was cutting corners. I'm not even sure it would have passed inspection in the USA.

I've come around to the idea of buying the more expensive (but still moderately priced) receptacles for high current applications, mostly so that the terminal is a V shaped pressure fitting at higher torque instead of screw on wire at lower torque. In the US, Bryant and Hubbel are two such vendors. While the topic was on my mind, I went out to my 14-50r to see what my electrician, whom I respect very much, had installed. Thankfully not the Home Depot/Lowes garbage, but an OK but not great Cooper.

I'm going to swap it out for a better receptacle, start with new wire ends, torque to spec and consider it a lesson learned: components have to be specified in the work order.
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

knightmb
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Re: Breaker thrown. I wonder what root source of problem was?

Tue May 11, 2021 7:16 am

The way the picture looks, the screw was only making contact with half the wire bundle, very unprofessional job by the electrician and they should know better. :shock:
That's amateur hour mistakes, don't hire that electrician again.
EatsShootsandLeafs wrote:
Mon May 10, 2021 6:40 am
Update, because I wanted to test a bit more first.

The black wire had not unseated itself, but when I removed it I saw this. A couple of the strands had fallen out/been ruined when the electrician installed it.

Anyway, I snipped off the last 1/4", reattached the wire, and was able to fill 2/3 of the battery on the Leaf yesterday at full amps with the black wire only feeling mildly warm instead of very hot (and it was very hot when I set charger down to 16A, previously). Breaker didn't throw. I will update this thread if this issue recurs but it looks resolved now. Thanks for all the posts!
How many times have you reset the tripped breaker and continued to use it? If a couple times, the breaker is likely OK to continue using, but if, say, 10 times, it should be replaced by a qualified person.
I think it threw 3 times, maybe 4. I know it's bad to have them trip too much so I didn't beat on it.

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wwhitney
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Re: Breaker thrown. I wonder what root source of problem was?

Tue May 11, 2021 7:48 am

SageBrush wrote:
Tue May 11, 2021 5:06 am
The use of Alu wire was a fat hint that the electrician was cutting corners. I'm not even sure it would have passed inspection in the USA.
Nothing wrong with modern aluminum wiring. Problematic aluminum wiring is historical; a different alloy was widely used for 15A and 20A branch circuits during the 70s. That alloy turned out not to work well with standard connections, due to an incompatibility in its coefficient of thermal expansion and connection not designed to handle it (I believe).

But the current electrical alloy has eliminated those issues. And aluminum wiring is not being made in sizes appropriate for 15A and 20A branch circuits, so its use is limited to larger circuits, which are typically point to point. As long as the terminations at both end are rated for aluminum, no problem.

Copper beats aluminum in basically only one metric: ampacity (how much current can be safely carried) per unit volume. Aluminum beats copper in ampacity per unit cost and ampacity per unit weight, [By unit here I mean per unit length, so unit volume is just cross sectional area.]

Cheers, Wayne

SageBrush
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Re: Breaker thrown. I wonder what root source of problem was?

Tue May 11, 2021 8:25 am

wwhitney wrote:
Tue May 11, 2021 7:48 am
But the current electrical alloy has eliminated those issues. And aluminum wiring is not being made in sizes appropriate for 15A and 20A branch circuits, so its use is limited to larger circuits, which are typically point to point. As long as the terminations at both end are rated for aluminum, no problem.
(My bolding above )

Good information, thanks.
I highlighted the IF, since an electrician (such as the one here) who does not pay attention to detail might also miss your point.
Question: Are the torque specs the same ? Or does the manufacturer have to give torque specs for each wire type ?
2013 LEAF 'S' Model with QC & rear-view camera
Bought Jan 2017 from N. California
Two years in Colorado, now in NM
03/18: 58 Ahr, 28k miles
11/18: 56.16 Ahr, 30k miles
09/20: 54.3 Ahr; 38k miles
-----
2018 Tesla Model 3 LR, Delivered 6/2018

wwhitney
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Re: Breaker thrown. I wonder what root source of problem was?

Tue May 11, 2021 9:31 am

SageBrush wrote:
Tue May 11, 2021 8:25 am
I highlighted the IF, since an electrician (such as the one here) who does not pay attention to detail might also miss your point.
Question: Are the torque specs the same ? Or does the manufacturer have to give torque specs for each wire type ?
As to the IF, yes it's important to check, but if you do I think you'll have find most/all breakers are rated for aluminum, and most/all large receptacles are. Hardwired equipment may well say in the manual "use copper conductors only" or the like; my EVSE said that. But if the equipment needs a disconnect in front of it, it would be fine to run aluminum to the (aluminum-rated) disconnect and then copper from there to the equipment; that comment in the instructions is just about the terminals. You could also just run aluminum and pigtail to copper with the proper connector (e.g. a Polaris style), although that's a bit of trouble.

My experience is not extensive, but the torque specs I've seen do not differentiate between copper and aluminum.

Cheers, Wayne

EatsShootsandLeafs
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Re: Breaker thrown. I wonder what root source of problem was?

Tue May 11, 2021 12:48 pm

SageBrush wrote:
Mon May 10, 2021 12:20 pm
Off topic since OP's problem is resolved ...

I pretty much know that technical responses in this forum from Whitney or Gerry are the the most valuable, followed by a select few others. Newbs are inundated with noise (or worse) and often flounder since they lack filters. This problem has plagued the internet forever. I still think that karma points are the best solution found so far, even though they sometimes are abused or manipulated.
I've noticed this on some rare topics over the 20+ years I've been online. Generally speaking one can get a lot of good advice, quickly, on a multitude of topics. But, rarely, some topic will produce weird responses--sometimes from a lot of people. Responses that are inconsistent with what professionals in an industry do.

Examples: I remember when I was doing my basement a lot of people online saying that stud walls need to be essentially on moving pillars so that if the floating slab moves up and down it doesn't shift the house off the foundation. I think they got this idea from who knows where and it just kind of grew like fake news.

Also a surprising number of people on forums think that burying gutter drains should be done not with the PVC specifically made for that (thin, light, cheap) but with schedule 40 heavy duty PVC.

goldbrick
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Re: Breaker thrown. I wonder what root source of problem was?

Tue May 11, 2021 4:15 pm

Things vary widely. In my area the soils are expansive and that is how basement walls are framed. It won't pass inspection otherwise and the drywalll will crack. Across the street, a new building is being built. They are drilling 20 ft holes that are filled with concrete. The foundation will be built on top of those pilings. That is a requirement for this soil type but obviously isn't done everywhere.

Reading forums does take some care to separate the wheat from the chaff. The more-professional forums are usually a good source of information but that requires being up to speed on the trade lingo. And sometimes even the pros don't agree. The NEC is contestable and is updated every few years. Things that were kosher on the 20xx code may not be allowed under the 20yy code, etc. I've seen forums where licensed electricians get into a huge pissing contest because they do things differently or interpret the NEC differently.

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