Quick question that's been bothering me, had to install a 30 amp single pole GFCI Siemens breaker the other day, the white pigtail coming off it was a #12 solid. How or why do you suppose Siemens gets away with that on a 30 amp? Suppose they figure the return on the neutral will never see 30 amps? And even if it does that short piece of #12 can handle 30? By contrast I had to install a 30 amp single pole GFCI in a SqD QO panel, and that had a #10 stranded wire attached to it. Just seems sketchy to me and I just don't get why skimp on something like that.
Siemens GFCI breaker
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Sberry
Senior Member
- Location
- Brethren, MI
- Occupation
- farmer electrician
Is it a test wire?
Didn't look like it, was all coiled up coming out of the breaker.
AC\DC
Senior Member
- Location
- Florence,Oregon,Lane
- Occupation
- EC
Maybe they justify it because a 12 can carry a lot more than the 20 we are allowed to use.
Put 90% connection at both ends of the wire and we can put on a 30 amp breaker
Also they are the manufacturer and have alot more playroom then we do
Put 90% connection at both ends of the wire and we can put on a 30 amp breaker
Also they are the manufacturer and have alot more playroom then we do
Sberry
Senior Member
- Location
- Brethren, MI
- Occupation
- farmer electrician
I was having a brain fart, it is a different type of wire with current rating different than building wire and limited distance.
I suppose. It was just regular 12 thhn.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
Maybe there is some reason they can get away with using the 90C rating of the conductors.
Or maybe someone goofed at the factory.
Jon
Or maybe someone goofed at the factory.
Jon
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
What was the single pole 30A for? All I have ever used that for was for an RV.
Yeah just an RV outlet
Hey got a call back from Siemen's, just wanted to get clarification if this was right or factory defective...basically he said its right, and because they are a manufacturer they don't have to follow the NEC, all they have to do is pass UL and they can do anything they want. I'm like wow, I suppose saving a nickel on using #12 instead of #10 adds up when you do a million of them.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
It is time to stop applying NEC installer requirements to products tested and listed to manufacturing standards. This is what 110.3 is all about.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Yep, $50,000. However I doubt they sell 1 million 30A 1 pole GFCIs per year though. 15 or 20A absolutely, but above that, it was pretty sparse sales volume as I recall (it's been almost 20 years now, I killed a lot of those brain cells...). Also, the savings would likely be less than a nickel per unit. But still it was likely 10s of thousands over time.
Someone might have received a percentage of that cost savings for coming up with that. When I was at Siemens if you came up with a cost savings measure, I think it was that you got a one-time bonus of up to 20% of the first year's savings. I knew someone at a factory in Juarez Mexico that got a bonus like that, I think it was $30k! I remember that he bought a huge motorhome with it.
Normally I wouldn't buck it, but when square D does their breakers with a #10, and the amount of defective stuff I've seen in the last couple years...just being cautious. If it's OK then it's ok.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Sq. D likely uses #10 so that they avoid getting the calls or returns for having #12, which would eat into the little bit of savings you might gain. I've made decisions like that in my design days.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Testing and listing standards have nothing to do with product quality.
My point is the NEC requirements are very conservative because they are primarily theoretical rather than proven through third party testing.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Yeah, just think how answering this question this one time eats into profits.