Pull boxes and ground

[Kevin.hndz]

I have about 5 one inch emts going into the same pull box my question is do I need a ground for each pipe to the box or is one ground in one of the pipes enough (from the pull box I have 3 one inch emts exiting into another pull box for another room and from that box 2 more into a last office )

 

[nickelec]

EMT is a sufficient equipment ground. You do not need a wire type ground unless it's a spec.

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[LarryFine]

If everything (conduit. boxes, etc.) is metallic, you don't need any EGCs.

 

[infinity]

I agree with be others, no EGC is required in any of the EMT raceways. So you could pull in an EGC in just one or two or all of them and of course in none of them. Your choice.

 

[Kevin.hndz]

I know the EMT itself is a mechanical ground but I noticed they pulled a ground into one of the pipes AND added a ground bar inside the pull box so it got me wondering are they going to pull a ground into each pipe entering the SAME pull box

 

[ptonsparky]

I know the EMT itself is a mechanical ground but I noticed they pulled a ground into one of the pipes AND added a ground bar inside the pull box so it got me wondering are they going to pull a ground into each pipe entering the SAME pull box

It's up to them. Entirely optional.

 

[tom baker]

An wire type EGC may be a job specification

 

[Eddie702]

Just my take. Using emt or pipe for an equipment ground is fine and has been proven to be better than a wire type ground.

But how many times have you seen EMT or ridged with loose locknuts and with EMT pipe pulled out of connectors and couplings. Some due to bad workmanship but in my opinion a wire type ground is good insurance.

Not to say if I am replacing an ac unit and there is no wire type EG And it is in metallic pipe if I can insure the pipe EGC is compliant i am not repulling the conductors.

In my area however it is common practice to pull an egc with any new work.

 

[infinity]

I know the EMT itself is a mechanical ground but I noticed they pulled a ground into one of the pipes AND added a ground bar inside the pull box so it got me wondering are they going to pull a ground into each pipe entering the SAME pull box

The ground bar is there to terminate the MC cables EGC's to the box. An EGC in the EMT is optional.

 

[Elect117]

Also, if there are splices made, then the EGC of that circuit, if of a wire type, should be spliced and bonded to the box. NEC 250.148

I see it often in commercial and industrial establishments where they just land the bar when they install the box to avoid future issues.

 

[LarryFine]

In the pic, there are already multiple green wires on the bar. Maybe it's there for MC cables, too.

 

[Dennis Alwon]

I suspect they will pull an equipment grounding conductor in each conduit

 

[VirutalElectrician]

I know the EMT itself is a mechanical ground but I noticed they pulled a ground into one of the pipes AND added a ground bar inside the pull box so it got me wondering are they going to pull a ground into each pipe entering the SAME pull box

Am I wrong or is that ~19 CCC in that one pipe?

 

[roger]

Am I wrong or is that ~19 CCC in that one pipe?

I don't know if there are 19 but it appears as though there are a bunch.

 

[infinity]

Am I wrong or is that ~19 CCC in that one pipe?

It looks like separate neutral so there should be an even number of CCC's. Also if those are #10's then 16 is the limit for 1" EMT.

 

[VirutalElectrician]

It looks like separate neutral so there should be an even number of CCC's. Also if those are #10's then 16 is the limit for 1" EMT.

That'd be at 50% derate, so they'd have to be on a 15amp breaker then, #12 or #10.

 

[Kevin.hndz]

That'd be at 50% derate, so they'd have to be on a 15amp breaker then, #12 or #10.

I brought all this up to them don't worry but yea I think they're planning on running separate grounds for each pipe

 

[infinity]

That'd be at 50% derate, so they'd have to be on a 15amp breaker then, #12 or #10.

With #10 conductors you could up to 20 CCC's before the derating gets you below 20 amps.

 

[Knuckle Dragger]

Just my take. Using emt or pipe for an equipment ground is fine and has been proven to be better than a wire type ground.

But how many times have you seen EMT or ridged with loose locknuts and with EMT pipe pulled out of connectors and couplings. Some due to bad workmanship but in my opinion a wire type ground is good insurance.

Not to say if I am replacing an ac unit and there is no wire type EG And it is in metallic pipe if I can insure the pipe EGC is compliant i am not repulling the conductors.

In my area however it is common practice to pull an egc with any new work.

I typically pull a ground. I've seen enough loose set setscrew or a loose or broken locken nut not to solely rely on the conduit as a bond.