Ran across Murray 200amp service panel with neutral bar that was added “floating”

[Dsg319]

How do these circuits even work? Cross neutrals somewhere out in the house?

Standard 40ckt service panel (pre emergency disconnect era)

Sometime along the line someone added an additional neutral bar and from what I can tell there is NO bonding screw nor a wire type bonding jumper so is no way physically attached to the service neutral in the panel. But obviously I still read continuity and circuits still work off this neutral bar.

I come across this while just adding a 50amp gfci breaker for a camper.

My question is how do these circuits even work? Just in series through the loads throughout the house that have the neutral that are on the original bonded neutral bar.

And possibly mis matched crossed neutrals somewhere in device box or j box?

Either way I’m going to install a wire typer bonding jumper back to the original neutral bar that is bonded to the panel.

 

[infinity]

Can you post some photos of the panel in question?

 

[retirede]

Disconnect the power and disconnect & ohm out each wire that’s currently on that bar.

 

[Dsg319]

Can you post some photos of the panel in question?

I currently don’t have any and won’t be back for several days unfortunately.

 

[Dsg319]

Disconnect the power and disconnect & ohm out each wire that’s currently on that bar.

Wouldn’t I have to lift each wire off the bar in question correct?

 

[Dsg319]

But just for theory’s sake say it is indeed floating no questions ask. How would those circuits on the floating neutral bar work?

 

[infinity]

Are there only neutrals on this additional neutral bar or are there also bare EGC's?

 

[LarryFine]

But just for theory’s sake say it is indeed floating no questions ask. How would those circuits on the floating neutral bar work?

Luck, or you're mistaken.

 

[Dsg319]

Are there only neutrals on this additional neutral bar or are there also bare EGC's?

Only neutrals

 

[LarryFine]

You could try an intentional heavy-load test and see if you can create an open-neutral imbalance.

 

[Pinnie]

My gut says your mistaken somehow.

 

[Dsg319]

My gut says your mistaken somehow.

I’d say I am. Or there is a cross tied neutrals somewhere splice somewhere but high unlikely as it would be carrying all the neutrals load off that bar on a #12

 

[Little Bill]

I’d say I am. Or there is a cross tied neutrals somewhere splice somewhere but high unlikely as it would be carrying all the neutrals load off that bar on a #12

Is the added neutral bar on plastic insulators?

 

[Dsg319]

Is the added neutral bar on plastic insulators?

Yup

 

[Dennis Alwon]

Yup

If the neutral is floating then somewhere one of the other neutrals on the bar must be connected to a neutral or an equipment grounding conductor.

 

[Dsg319]

If the neutral is floating then somewhere one of the other neutrals on the bar must be connected to a neutral or an equipment grounding conductor.

My thoughts exactly.

Once I get back I’ll bring my inspection light just to verify there is nothing bonded anywhere I can see in the panel. Sometimes I’m glad electrical equipment isn’t snakes.

 

[LarryFine]

Either way I’m going to install a wire typer bonding jumper back to the original neutral bar that is bonded to the panel.

Perhaps there already is one you missed.

 

[retirede]

Wouldn’t I have to lift each wire off the bar in question correct?

Yes. If you’re lucky, you’ll hit the problem circuit early!

 

[Dsg319]

Went back with my Milwaukee light today while trouble shooting some garage receps and double checked the main panel and it has the factory black insulated neutral strap from one bar to the other and I somehow missed that the other day lol.

 

[kwired]

Wouldn’t I have to lift each wire off the bar in question correct?

Maybe try checking continuity before ever lifting any, if you have none then it is isolated. If there is continuity you still don't know where the bond is and may not be in an appropriate place.

Or check for any voltage between them. If it is floating any voltage you measure is because of unbalanced loading.