SqD QO NG Bonding screw too small

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ModbusMan

Senior Member
Location
Cleveland, OH
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Building Automation Engineer
A couple years back I had my FedPac panel swapped out for a QO142M200P. So far, so good. Last weekend, I was hooking up a piece of gear we're thinking of using at the office (Janitza UMG-804 for those curious... to be proven out as an alternative to Veris E30/E31) and noticed that the NG screw was missing (a quick search found it together with the unused breakers). As the first disconnect immediately after the meter, code says it should have been installed, but unless I'm looking at the wrong hole, it's way too narrow for where SqD's videos say it should go. The tradesman who did the work was someone we had on staff for a good fifteen years and hardly an idiot, meanwhile SqD's tech support has given conflicting answers, including that the NG terminal block at the top wasn't electrically connected (despite being the same chunk of metal). To me, it looks as if the neutral and ground bus bars are already connected across the entire top, rendering the NG screw redundant, but I haven't done live panel work myself in about eight years, and even then it was on data center fPDUs where this wasn't even a consideration, so I'm hoping someone still doing this on the daily can tell me what's going on, and whether or not I need to actually do anything.
https://imgur.com/a/eChvxo9
 
Since this panel contains the service disconnect the MBJ (green screw) is required to be installed. I would guess that there is a bond somewhere else (like on the bare GEC) so the system is bonded just not to code. Wider shot photo's may confirm this.

Welcome to the forum. :)
 
Thanks for the confirmation and welcome, infinity. The original shot (linked) doesn't really provide much more (apart from seeing more of the bus bars and a couple split-core CTs) since this was a standard panel from our local electric house. If a different view would be more instructive, I'll be more than happy to get what's needed.

About the only potentially helpful things I can add are that when my coworker did the swap, he used the inner two bars for grounds and the outer for neutrals, the connection to the cold water pipe is the fifth ground down on the left hand side, and that all four bars seem to be connected via the "not quite torx looking rivets(?)" that are second from the top on each. It's these connections that make me wonder if the MBJ screw would be redundant. Besides being too large diameter for any of their screws, the hole where SqD's videos seem to say it belongs doesn't appear to connect to anything, but I have a hard time believing that such a glaring defect wouldn't have resulted in a recall by now (but then again, FedPac never got recalled to begin with, sooooo.....). Maybe a case of the standard screws are for 100/125/150A panels, and 200A needs the next size up (good luck finding one)?
https://imgur.com/a/IyLbQMZ
 
Is that part number correct? That does not look like a plug on neutral panel. Does the labeling say “Service equipment only”, or something to that wording? If Service equipment only, the neutral probably is already bonded as you said. Both upper and lower bars would be neutral and equipment grounds.
 
Definitely the correct part number (unless the label itself is wrong), and definitely plug-on neutral (you can barely make out the zig-zag just below the main breaker, coming off the inner bus bars). Here's a shot of the nameplate the SqD tech support guy asked me for:
https://imgur.com/a/qxWLDtv
 
Ok, picture didn’t show the neutral buss further down. The neutral is definitely insulated, and will require bonding to the can. I have a feeling the screw may have been put in, but over tightened and broke off, or stripped.
 
Went downstairs and pulled the dead front off to get a couple more (hopefully more useful) pictures. I didn't see anything that looked broken or stripped, so no easy answers there unfortunately.

Entire interconnect area:
https://imgur.com/aO1rYAl

Close-in of those torx-looking screws that are second from the top on all four bars:
https://imgur.com/a/xqAS7FD

The MBJ included with my panel in relation to where the instructions seem to say it belongs:
https://imgur.com/5n2atZE
 
augie47 said:
Before I'd fret any more over it I would make me a 250.102 jumper and bond the can to the neutral bar.
Click to expand...
It may already be there, I can't see enough to determine it in the pictures.
 
retirede said:
Stating the obvious just in case - you do realize that the bonding screw threads into the can, not the bus bar?
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Did not know this and didn't appreciate the ramifications at first since everything in my communications world is "If it's meant to connect, it'll fit like Legos," but it got me to thinking and doing more searching, which led to this third-party vid on YT that appears to be my exact panel (minus PON), and suggests that the problem is (surprise!) me... in that I need to put more pressure on it so the screw pushes the front bar down and then reaches the back hole.

roger said:
It may already be there, I can't see enough to determine it in the pictures.
Click to expand...
I'm going to head downstairs shortly to test my "push harder" theory, but if that doesn't pan out, let me know where to point the camera, and I'll try to snap what you need to confirm.
Ed: On second thought... 8pm on a Friday night isn't the best time... I'll fuss with it in the morning when I'm more rested.

augie47 said:
Before I'd fret any more over it I would make me a 250.102 jumper and bond the can to the neutral bar.
Click to expand...
Could end up being what I do just for peace of mind. Inspectors can't (unfortunately) flag a FedPac, but they might ping this when I sell in however many years.
 
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ModbusMan said:
Did not know this and didn't appreciate the ramifications at first since everything in my communications world is "If it's meant to connect, it'll fit like Legos," suggests that the problem is (surprise!) me... in that I need to put more pressure on it so the screw pushes the front bar down and then reaches the back hole.

.
Click to expand...

Since the threads in the can have paint in them, a little oomph is needed to get the screw started.
 
retirede said:
Since the threads in the can have paint in them, a little oomph is needed to get the screw started.
Click to expand...
Makes sense (our physical networking team complains every time they're sent telco racks with powder-coated mounting holes), though I wouldn't have expected paint inside something that literally requires metal-to-metal contact. There's inserts for that sort of thing! Anyways, I'll post up again in the morning after I've had a chance to push harder on that screw.
 
ModbusMan said:
Makes sense (our physical networking team complains every time they're sent telco racks with powder-coated mounting holes), though I wouldn't have expected paint inside something that literally requires metal-to-metal contact. There's inserts for that sort of thing! Anyways, I'll post up again in the morning after I've had a chance to push harder on that screw.
Click to expand...

The screw is an aggressive self-tapping design. It will wipe all the paint the first time through. If it didn’t have paint from the factory, the threads would be full of rust by now!
 
The screw is in and we are bonded! Thank you all, especially retirede for sending me down that "It lands on the can, not another bar" clue. Now if only the SqD guy could have said "Yeah, grab a drill, put a driver bit on it, and give it some elbow grease" at the very beginning... Their YT video makes it look like another of my "everything is built to fit perfect" comm lines.
 
hillbilly1 said:
Is that part number correct? That does not look like a plug on neutral panel. Does the labeling say “Service equipment only”, or something to that wording? If Service equipment only, the neutral probably is already bonded as you said. Both upper and lower bars would be neutral and equipment grounds.
Click to expand...
That is a PON panel, you can see the lugs that connect to the PON buses, just below the main breaker at the bottom edge of the photo.

QO loadcenters don't have any suitable only for use as service equipment that I am aware of. They all are convertible with the bonding screw as well as have convertible main breaker vs main lugs ability. Some the three phase can only be converted to main breaker via back fed breaker though, but all the single phase are convertible.
 
hillbilly1 said:
Ok, picture didn’t show the neutral buss further down. The neutral is definitely insulated, and will require bonding to the can. I have a feeling the screw may have been put in, but over tightened and broke off, or stripped.
Click to expand...
Quality control has taken a hit in recent years, probably packed in the wrong screw would be my guess.
 
retirede said:
Stating the obvious just in case - you do realize that the bonding screw threads into the can, not the bus bar?
Click to expand...
Good point, the screw he pictured looks like the correct one. It goes all the way to the can and you do need to exert a little force as it is "self tapping" into the can first time it is installed.

If it hits the shoulder of the screw before any turning then they packed the wrong screw and is likely too short or too small diameter wise.
 
kwired said:
Quality control has taken a hit in recent years, probably packed in the wrong screw would be my guess.
Click to expand...
Quality every where is an issue, though in this case it was the correct screw, just shorter than it probably should be. I'm a little surprised, given that my coworker used a resi contractor's kit with main breaker (making the odds of being a sub-panel pretty low), that the screw doesn't also come installed just as a courtesy.

kwired said:
Good point, the screw he pictured looks like the correct one. It goes all the way to the can and you do need to exert a little force as it is "self tapping" into the can first time it is installed.

If it hits the shoulder of the screw before any turning then they packed the wrong screw and is likely too short or too small diameter wise.
Click to expand...
Yeah, screw's shoulder would rest on the bar when I first tried to put it in myself, otherwise I probably would have pushed harder to begin with and never needed to create this thread. I could only get enough leverage with my screwdriver to get just the first or second threads engaged, but the guy in the YT vid I linked a couple posts up was bearing down pretty hard on the thing, so I ended up grabbing my drill, putting in a flathead driver bit, and solving the pressure problem that way. SqD could solve things by making the screw an eighth of an inch longer (cheap) or doing it themselves (not so cheap).
 
ModbusMan said:
Quality every where is an issue, though in this case it was the correct screw, just shorter than it probably should be. I'm a little surprised, given that my coworker used a resi contractor's kit with main breaker (making the odds of being a sub-panel pretty low), that the screw doesn't also come installed just as a courtesy.


Yeah, screw's shoulder would rest on the bar when I first tried to put it in myself, otherwise I probably would have pushed harder to begin with and never needed to create this thread. I could only get enough leverage with my screwdriver to get just the first or second threads engaged, but the guy in the YT vid I linked a couple posts up was bearing down pretty hard on the thing, so I ended up grabbing my drill, putting in a flathead driver bit, and solving the pressure problem that way. SqD could solve things by making the screw an eighth of an inch longer (cheap) or doing it themselves (not so cheap).
Click to expand...
The problem is, if the panel is mount on block or concrete, the screw will hit and strip out.
 
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