I think that is an interesting question, and I would like to be able to figure out the correct answer to that one. Unfortunately, the Siemens panel that I have only has a neutral bar on one side since it has less than 30 circuits (30 and above have two neutral bars -- one on each side).
I called Siemens technical support on Friday afternoon shortly before 5 PM. I explained that I want to be able to add a second neutral bar to my
20-circuit Siemens panel and asked if there is a way to do that. I also explained the option/idea above of adding a ground bar and connecting that to the neutral bar with an #6 or #8 wire.
The call-taker entered my question into their system and created an email "ticket number", and then said that a technical representative will get back to me on Monday. I'll pass on whatever I hear back from them.
Its near impossible to get homeowners insurance on a home with knob and tube.......
now you can deny that all you want but it doesnt change reality
homeowners insurance these days often send out a inspector before writing a new policy......
they look for trash under a porch, lack of railings, bad roofs, fuse boxes, unsafe sidewalks...... all of these and more will have to be corrected before getting insurance....
I agree with these rules, since everyone wants low preminms, and all of those can and do boost losses. it might be possible to get a policy with known hazards, but it might boost premiums significantly.....
incidently a customer of mine had sidewalks that were uneven. the slabs were at different levels:( the customer was a public school. A student got ill and grandpa was called to take the kid home.
grandpa tripped on the uneven sidewalk and broke his hip. within 2 months he died, cause, the fall.
the school had to pay all the medical bills, pain and suffering, etc etc. last i heard the settlement offer to grandpas family was half a million dollars.... paid by the schools liability carrier.
the district replaced all the sidewalks at all the buildings and repaved parking lots etc. the insurance company required a risk inspection and repair of all possible hazards to keep their coverage.
now what really caused the accident? the school board insisted on a budget cut on building maintence to save money....
the board members who voted for that cut were all gone, replaced or voted out.
sadly and for practical $ reasons there are individuals doing that today. save money by no maintence...
thats why insurance now inspects homes. with the stormy weather probably from global warming entire citys are being destroyed. insurance cant prevent that but can save money on preventable losses
But what happens if the unbalanced load happens to be larger than the conductor? Theoretically, the unbalanced load could be 100 amps. I agree that is very unlikely, but statistically, it's possible. Let's say you had some house where 8 resistance heaters are used. They could just happen to put them into outlets that are on the same leg..... 12A * 8 = 96A.
Here's another point. An add-on ground bar is designed to be attached via screws to the panel metal. If you use one of those as intended, for a ground bus, then under normal conditions, no current is ever flowing in the panel metal, right? You'd only have current flow throw the panel itself if there was a ground fault of some kind. That's how it works with any metal box, right?
But if you use that add-on ground bar as a neutral bar, then you do have at least part of the unbalanced current flowing through the panel metal all the time. Even with a wire connected between that neutral bar and the other neutral bar, the current will split with some of it going via the wire, some of it going via the panel metal. That doesn't seem right to me. I would think the right way to do it would be for that additional neutral bar to be installed insulated from the panel so that all the current has to flow via the wires and not through the panel metal.
Not saying this is really unsafe if it's done the way you guys are saying. Just that it seems odd to me that the code is OK with using the panel metal case as a current carrying conductor. I can't think of another instance where that is allowed.
Of course they could. Anyone can sue anyone for just about anything. Whether they have a real case, can they prove it, will they win, how much is it going to cost them in legal fees to find out, that's an entirely different matter.
If you want to sue because the kitchen tile floor is uneven and it was clearly uneven when you bought the place, walked through it, had the opportunity to inspect it, etc, then I don't see how in any rational court of law you'd win. Of course if you were selling the place, you wouldn't have that problem because you'd tell the buyer that the floor doesn't look quite right to you, they'd say "Gee, you're right, we want $4K off for a new one." And you'd both be happy.
If you find out the foundation for a room that was added on DIY is sinking because it was built on marshmallows instead of footers, that it was done by the seller, no building permit, they didn't disclose it, etc, then you probably have a decent case.
Sue their insurance company for a defect on a house they bought? Per the above, sure they could. But on what basis could they ever win? What did their insurance company have to do with some house defect that they later find?
I believe the last time you brought up the issue of buyers coming back to sue a seller for anything and everything that wasn't disclosed, I provided a link to the PA real estate disclosure law. Did you read it? As I recall, it said that buyers have 2 years to bring a suit. It also said that just because some housing component, say a roof or septic system is at, near or beyond it's normal expected life, that doesn't mean it's a material defect that has to be disclosed, provided that component is still functioning OK.
You are correct. A # 6 copper is all that is required to carry the full neutral load of a 100 amp service, so considering that this is a supplemental neutral bar, it's never going to carry close to the full amount.
To be used as a secondary neutral bar as opposed to a ground bar, it must be connected to the original bar by something more substantial that the steel of the cabinet
No it would not, because the panel metal is not in the conductive path of the current. With the existing neutral bar, current flows from the neutral on each circuit into the neutral bar and to the service neutral which is directly connected to the existing neutral bar. There is no alternate route in the panel metal for current to go.
Now let's say you add a ground bar on the other side of the panel, connect it back to the existing neutral/ground bar, and use it as a neutral. In that case you have two paths for current from that additional neutral to go to get back to the service neutral. One path is via the wire connecting the two. The other is via the panel metal. That second route didn't exist until you created it.
Again, not saying this is the worst thing in the world, or that it's inherently unsafe, or that an inspector is going to fail it. I just think it's a curious situation and wonder about the code aspect of it because you're now using the panel metal as a current carrying conductor. That just doesn't seem right. If you installed that additional neutral bar as an insulated one, then you would not have current flowing in the panel metal, only the wire connecting it to the original neutral.
I still don't get how a #6 can be used to carry the full neutral load of a 100 amp service. Worse case, the full neutral load is 100 amps. You can't use #6 to connect the hots on a 100 amp sub-panel, can you?
I agree the "chances" that the neutral is ever going to see the full 100 amps is small, because it's only the unbalanced portion. With 120V randomly assigned to one hot or the other, they are going to tend to cancel out and the neutral current will be small. But it is possible to put the full 100 amps on the neutral if you managed to put a bunch of large 120V loads all on the same hot leg. Like plugging in say 8 resistance heaters into 8 circuits that just happen to be all on the same hot leg. I guess maybe the answer is that even if you put
100 amps through a #6 it's not the end of the world, ie it's not going to fail or get hot enough to start a fire, etc.
There aren't the same insulation temperature issues with bare copper, clamped to the box on both ends (heat sink), inside a large enclosure (instead of threading through insulation).
Just to follow up . . , I still don't have a definite answer from Siemens on this question.
Here is what I wrote to Siemens:
"My question is in regard to the cat# S2020B1100 Main Breaker Load Center. It comes with only one neutral bar (on the right side). I would like to add a second neutral bar on the left side of the panel.
Is there a way for me to do that?
It has been suggested to me that I could possibly do this by adding a Siemens ground bar on the left side and then connecting a #6 or #8 jumper wire from the new ground bar to the original neutral bar, thus making them both useable as neutral/ground bars.
Is that correct, or is there a better way to add a neutral bar on the left side?"
And, this is what they wrote back yesterday:
"I am checking to see if there is an offering for this. I will advise."
My guess is that they are going to say that there is no option to add a second neutral bar to their cat# S2020B1100 Main Breaker Load Center. But, that I can add a ground bar to the panel.
I doubt that they would want to get into giving out advice on how to create or wire a second neutral bar since that model panel does not come with a second neutral bar.
Also, I went to Home Depot and I looked at the box etc. for the same model Siemens Main Breaker Load Center, and it specifically says, "Ground bar not included". I think I remember the instructions inside showing how to add a ground bar (I'm not sure). And, Home Depot does sell the ground bar and shows how to install it as a ground bar.
I added a bar to a existing cabinet once. The added bar and existing bar both had spots for 12 gauge or smaller wire.
Plus each bar had significantly larger spots for heavy conductors. perhaps a electric stove or something like it
So added 2 copper heavy tie lines between the old and new bar, figuring that would never cause a problem:) plus the bar was bonded to the cabinet
I had to get middle states to reinspect the cabinet for home sale, the inspector complimented me on my good job........
the existing bar had issues many of the screws were like welded on place, they must of been overtightened at one time and the heads would break off when loosened. i had ven tried heating some. the quick project took all day:(
For residential, you can use #4 if the service is 100A. This is based on "diversity".
You are real unlikely to have a bar total load connected to one leg that is a problem with #6, and there is also "diversity". But, as you say, it is possible. A person could be a little careful about what is connected.
I would rather use a ground bar as a ground bar unless there is a good reason to have to land neutrals on it.
The wire is connected to the neutral bar and the ground bar.
There are limits to the wire amp rating based on the connections to the wire. Unless the connections are rated for a higher temperature, in general for 100A circuits or less the wire can only use the amp rating for 60 degree C insulation. (Breakers may, for example, be marked for
Which I'm sure you'd agree is an interesting concept. By diversity I assume they mean that the statistical probability of someone putting 100A of load all on one leg is low. I think we all agree, it's low, but it's not zero.
Which is cool if it's a fixed installation of some known equipment. But it could be a house where someone could plug in a bunch of resistance heaters and have them by chance wind up on the same leg.
I agree. That was my first suggestion and everyone agrees it's 100% kosher. Use the new ground bar for grounds, move some existing grounds from the neutral/ground bar over to it, thereby freeing up more neutrals.
What are your thoughts about what I pointed out about current flow through the panel itself? If you put a ground bar on the other side of the panel, it's bonded to the panel. Even if you connect it with a heavy wire back to the original neutral, you still will have current dividing, with some of it going through the panel metal. I would think the better option would be to install an insulated neutral bar.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.