Sup panel troubleshoot

[PowerdT]

I have an old 120/208V 3 phase panel with 4 wire and no ground, the conduit is used as a ground.

when I open the panel I saw some of the branch circuit terminated on the neutral bar.

I am afraid this is proper installation however one of electrician said its normal?

When u measure the neutral and ground, is it normal to get continuity?

 

[infinity]

What do you mean by branch circuits terminated on the neutral bar? Do you have any photo's?

 

[ptonsparky]

Does ground mean Equipment Ground?
or
Does ground mean Grounding Electrode?

Sounds like you mean the conduit serves as an EG.

The neutral bar should be isolated from the enclosure. No EG should be landed on the Neutral bar.

You should get continuity from neutral to EG because they will be bonded together at the Service Entrance. No where else.

Separate buildings and an old installation may have allowed the bond of Neutral to the enclosure at the Service Disconnect for a separate building.
In that case you would be required to have a Grounding Electrode System at that building.

 

[PowerdT]

Does ground mean Equipment Ground?
or
Does ground mean Grounding Electrode?

Sounds like you mean the conduit serves as an EG.

The neutral bar should be isolated from the enclosure. No EG should be landed on the Neutral bar.

You should get continuity from neutral to EG because they will be bonded together at the Service Entrance. No where else.

Separate buildings and an old installation may have allowed the bond of Neutral to the enclosure at the Service Disconnect for a separate building.
In that case you would be required to have a Grounding Electrode System at that building.

Yes I meant EGC. the neutral has to be isolated from the panel enclosure.

Thank you.

 

[ptonsparky]

Yes I meant EGC. the neutral has to be isolated from the panel enclosure.

Thank you.

Under load you should notice a small voltage drop N-EG. One of my older testers would have a clean beep for continuity. A 60 cycle hum would be apparent on neutral to EG tests at sub panels or branch circuits if the neutrals had a load on them.

 

[tom baker]

Terminology in grounding and bonding is important. Look up the definition of ground.
See what I mean?

 

[PowerdT]

What do you mean by branch circuits terminated on the neutral bar? Do you have any photo's?

Branch circuit EGC on neural busbar

 

[augie47]

Only if it's a service panel or an old installation on a detached structure with no EGC with the feede and your metallic conduit rules that out.

 

[Dennis Alwon]

If this is a sub panel then you are correct that neutrals and equipment grounding conductor's must be separated.

 

[PowerdT]

Only if it's a service panel or an old installation on a detached structure with no EGC with the feede and your metallic conduit rules that out.

It’s old panel with no feeder EGC, and it’s not on detached structure. Commercial building

 

[ptonsparky]

Your electrician is wrong. Send them to a code class.

 

[PowerdT]

Your electrician is wrong. Send them to a code class.

I will add busbar and separate the neutral and the EGC and make sure neutral bar is not touching the panel enclosure