Neutral Strap Removal

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mdauck

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We have a Siemens Load Center G3040B1200-CU with what would appear to be a removable Neutral Strap. Our local inspectors for this project have asked that we place a grounding buss bar on the panel and remove the grounds from the neutral buss and attach them there. It would be far easier to remove this strap and reset the grounding bond screw to accomplish the same task. The panel is already in place and fairly dense with wire, and adding this step would be cumbersome.

This panels neutral bus can be separated by removing this strap and also moving the bonding screw (green). We?re trying to find any literature or information that would state if it voids the warranty or if this series of panel was designed to allow for these conditions.
 
It sounds as though this is a sub fed panel, (I'm assuming there is a four wire feeder supplying the panel) this would mean the neutrals must be isolated from the EGC's and the panel enclosure.

The neutral bar would need to be mounted on isloators and any jumper (strap or screw) bonding it to the enclosure would need to be removed.

A ground bar would then be installed and bonded to the enclosure with all the EGC's landed here.

Roger
 
This is a common mistake by a ton of beginner electricians along electricians who have been in the trade for a while but have never recieved formal training.

Basically what they are telling you is that when you bond the neutral and the ground on a sub feed panel. The returning path on the neutral or better called grounded conductor also shares the path with the conduit and the green, or grounding conductor.

If for some reason you were to get a loose neutral then the return path would be through the ground path.

I myself made this mistake for years and never really understood it until I studied a few books on grounding.
 
Neutral Strap

Neutral Strap

Thanks for the quick responce. Yes this is a sub panel coming from a 200amp disconnect with 4 conductors being fed to it. I understand the grounding and bonding and isolated issues involved. What I have in question is can the bar strap be removed to provide to two isolated points. One being the Neutrals on the right and the Grounds on the left. We've already wired the panel as such and by removing this bar and reseting the bonding screw from the White side i.e. left side over to the Ground/Bond side it would solve the problem. We just didn't feel it was necessary to employ another bonding/ground bar, move the copper grounds and all if we could "rightfully" remove the Strap.

It looks as if this panel was designed to do that if the application was required. The bar will easily unscrew and slide to the left to be removed and the Bonding Screw has two places, either on the left or right side of the two busses.
 
I use Siemens quite a lot and I'm familiar with your application.

The (metal) strap that you removed is used to connect (bond) the two (factory installed) ground bars together.

Both (factory installed) ground bars are mounted on plastic (isolating) mounts
and one bar is bonded to the panel enclosure.

This strap is required if the panel is used as service equipment with a single phase, 3 wire feed.

The grounded service conductor lands on this common ground bar.

The branch circuit grounded (neutral) and grounding conductors land on this ground bar.

If the panel is used as a sub-fed panel with a 4 wire (single phase) feeder, the grounded (neutral) terminal bar must be isolated from the grounding bar and the panel enclosure.
Removing this metal strap will give you a isolated neutral bar and a bonded grounding bar.
I assume that this is what you've done.

Siemens makes a plastic strap to replace the metal one that you removed.

It is listed on the cover as a accessory part.

This is what I normally do when I install a Siemens panel, although, if you read the instructions on the cover, it's not really clear if this is the proper installation.

I figure that since Siemens makes a plastic (non-conducting) connecting strap, it's intended to provide isolation and (non-conductive) rigid support between the grounding bar and the grounded (neutral).

Since it's offered as a accessory, it's probably required.

Both bars come from the factory mounted in plastic mounting blocks and the installation of the plastic strap will only give additional support to both bars.
The panels come with lugs at the top of each (factory) ground bar for (service) cable connections, so it all add up to me.

Why else would they make a plastic jumper (strap) if not to isolate the two ground bars from each other?

If they are isolated from each other and one is bonded, what other use could the other bar possibly have, other than use as the grounded (neutral) terminal bar?

Why would they put so many terminals on each bar (30+ on a 40 space panel) if this was not their intent?

I know that they offer a grounding bar as a accessory, and that this accessory bar is intended to be mounted directly to the enclosure, so the confusion (in my mind) as to whether this is the proper installation.

I've never been hit on a installation doing it this way, and I can see no reason that it's not a safe way to do it, I'm just not sure that this is what Siemens intends.

I would get the replacement (plastic) strap, install it and let the inspector tell me why it's not a code worthy install.

Just my opinion and a few other thoughts.
steve
 
Excellant. I figured someone out there had seen this or had been through it. I will acquire the plastic part to which you mention. This will save time and money and it makes perfect sence. Thanks again. We'll see what the inspection has to say later.
 
dduffee260 said:
This is a common mistake by a ton of beginner electricians along electricians who have been in the trade for a while but have never recieved formal training.

I have seen this mistake by "Qualified?" electricians some from the ABC school others from IBEW schools, all with several years post school expierence and licenses in their pockets. When asked why? they responded with a variety of answers, none of which are acceptable.
Click to expand...
 
m73214 said:
I've never seen one and can't imagine why one would need to install one.
Click to expand...



I hadn't either until about 5 years ago.
I got introduced to them by a really picky inspector.
Like you, I don't see the reason for them since the ground bars are already secured by the plastic mounting. Plus, after the conductors are installed, they are really secure.
steve
 
I`ve always just removed the strap and tied the neutrals on the non bonded side and the grounds on the bonded side.But if siemmens has these straps to replace the metal ones I would imagine that not installing them would be a listing violation.I will admit that when i first removed the metal strap it seemed kinda cheesy with the movement that the bars do.Yes they get secure when connected but it did seem really flimsy when the metal bar is removed.
 
Neutral Strap Removal

It is important that the panel be listed for the purpose,by the manufacture to avoid defeating the listing.

IMO
 
hillbilly said:
I use Siemens quite a lot and I'm familiar with your application.

The (metal) strap that you removed is used to connect (bond) the two (factory installed) ground bars together.

Both (factory installed) ground bars are mounted on plastic (isolating) mounts
and one bar is bonded to the panel enclosure.

This strap is required if the panel is used as service equipment with a single phase, 3 wire feed.

The grounded service conductor lands on this common ground bar.

The branch circuit grounded (neutral) and grounding conductors land on this ground bar.

If the panel is used as a sub-fed panel with a 4 wire (single phase) feeder, the grounded (neutral) terminal bar must be isolated from the grounding bar and the panel enclosure.
Removing this metal strap will give you a isolated neutral bar and a bonded grounding bar.
I assume that this is what you've done.

Siemens makes a plastic strap to replace the metal one that you removed.

It is listed on the cover as a accessory part.

This is what I normally do when I install a Siemens panel, although, if you read the instructions on the cover, it's not really clear if this is the proper installation.

I figure that since Siemens makes a plastic (non-conducting) connecting strap, it's intended to provide isolation and (non-conductive) rigid support between the grounding bar and the grounded (neutral).

Since it's offered as a accessory, it's probably required.

Both bars come from the factory mounted in plastic mounting blocks and the installation of the plastic strap will only give additional support to both bars.
The panels come with lugs at the top of each (factory) ground bar for (service) cable connections, so it all add up to me.

Why else would they make a plastic jumper (strap) if not to isolate the two ground bars from each other?

If they are isolated from each other and one is bonded, what other use could the other bar possibly have, other than use as the grounded (neutral) terminal bar?

Why would they put so many terminals on each bar (30+ on a 40 space panel) if this was not their intent?

I know that they offer a grounding bar as a accessory, and that this accessory bar is intended to be mounted directly to the enclosure, so the confusion (in my mind) as to whether this is the proper installation.

I've never been hit on a installation doing it this way, and I can see no reason that it's not a safe way to do it, I'm just not sure that this is what Siemens intends.

I would get the replacement (plastic) strap, install it and let the inspector tell me why it's not a code worthy install.

Just my opinion and a few other thoughts.
steve
Click to expand...


If you are using this box as a main SEP, which I intend to do, wouldn't this be the proper installation? Assuming that the neutral bus is the bus with the large lug and bonding screw and the grounding bus is the bus with the smaller lug.

*2/0 copper from meter to box
*#4 copper from ground bus to water pipe
*#4 copper from ground bus to double ground bars
*Drive the bonding screw on the neutral lug into the panel
*Leave the neutral bus to grounding bus strap in place
*Run all branch neutrals to neutral bus with big lug
*Run all brach bare copper grounds to ground bus with smaller lug

The Siemens load centers come with no diagrams or instructions. I called Siemens and the rep didn't seem like he knew what he was talking about at all. He told me to remove the ground strap if I used the bonding screw.
 
Maybe I am confused here...... If you had the bonding screw in place and the strap in place , first why would you need to place the neutrals and ground wires on separate bars at all ???Maybe i assumed , but if there were to be a separate ground bar that would only be done to, IE: isolate the grounded and grounding conductors for a sub panel.If it is indeed a sub panel 4 wire install these must be isolated and the strap removed.If I remember right the buss with the larger lug is the buss that can be bonded, but I might be wrong here.If memory serves me well I had to use an add a lug when using the panel as a sub panel.Been several years since I have used Siemmens panels.
 
Neutral Strap Removal

brian john said:
dduffee260 said:
This is a common mistake by a ton of beginner electricians along electricians who have been in the trade for a while but have never recieved formal training.

I have seen this mistake by "Qualified?" electricians some from the ABC school others from IBEW schools, all with several years post school expierence and licenses in their pockets. When asked why? they responded with a variety of answers, none of which are acceptable.
Click to expand...

I once found a sub-panel with the neutral and egc bonded together on a service inspection of a new home.I had the electrician correct it and explained why the 2 had to be isolated. When I went back for the final inspection,I found the chime transformer secured to a ko in the panel and the egc of the transformer terminated on the neutral bar. (Go Figure)
Click to expand...
 
mdauck said:
It looks as if this panel was designed to do that if the application was required. The bar will easily unscrew and slide to the left to be removed and the Bonding Screw has two places, either on the left or right side of the two busses.
Click to expand...

GE has the same setup and I do it all the time on a subpanel. Any inspector who turns that down is far too concerned with asserting his authority than he is in understanding the situation. There is absolutely no problem with it from I could make of this discussion. The neutral is isolated and grounds are bonded to the can with the equipment already given. They make that strap removeable for a reason, IMO. Do it--- and fight the SOB
 
I think that the reason the inspector required it is because Siemens does (or did) make a plastic strap to replace the one made of aluminum.
If it's made, it has to be used or violate listing.
It also costs way too much for a piece of plastic.
IMO...Siemens should provide it with the panel.
It would probably cost them about 5 cents each.
This guy is really a PITA.
I believe he stays on top of items like this just so he can write citations.
Luckily, I don't see him very often.
steve
 
hillbilly said:
If it's made, it has to be used or violate listing.
Click to expand...
I would want to see " ... and required in the instructions ... " added to that statement before proclaiming " ... it has to be used ... "
 
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I just read a little info on siemens panels and I guess if it were the "right" thing to do , the removal of that strap that connects the neutral bars , the bars we are allowed to put grounding conductors to ,only if there is enough space for them, Why don't they do it? Instead they install a ground bar in their main lug panels. I'm not saying it is the worst thing to do, but it is a neautral bar and not a grounding slash neutral bar. When you remove that strap you have just made something into something other than what it was intended to be.
I have also used many siemens panels and never have seen this plastic strap.
 
LarryFine said:
I would want to see " ... and required in the instructions ... " added to that statement before proclaiming " ... it has to be used ... "
Click to expand...


I was just stating what I was told by that particular inspector.
This was about 5 years ago, and I'm not even sure that Siemens still offers this replacement strap.
I haven't used one since (plastic strap that is).
The panel I was using had the strap located at the bottom of (and connected between) the ground bars.
As I said, Siemens did make this plastic strap as a accessory at one time.
Now? I don't know.
steve
 
I looked at a new Siemens MBP panel yesterday and it specifically stated that removing the strap between the ground bars and using one for a grounding terminal bar was OK.
It said to remove the strap, bond the bar on the left to the enclosure with the included jumper, add a lug kit (ECLKB1) to connect the feeder grounding conductor, and use it as a grounding terminal for branch circuits.
This panel was a model# G3040B1200...200Amp..30/40 space Main breaker panel.
I believe the Main lug Panels come with the lug for the feeder grounding conductor.
I take this to mean that Siemens no longer makes the plastic replacement bar, and that it is not necessary anymore.
steve
 
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