Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
When you have an MIGB on the conduit what work is involved to actually bond it to enclosure? Thank you.
Bond
- Thread starter Alwayslearningelec
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician
You'll need to attach the proper size bonding jumper to the bushing and the other end to the EGG bus. Depending on the size and length of the jumper this could take quite some time.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
A separate bonding jumper through the conduit to the bus?????
Why not just bushing to box?
- Location
- Illinois
- Occupation
- retired electrician
No, but if you have an internal grounding conductor of the correct size you can just loop it through the lug on the bonding bushing and then land it on the grounding bus.
You can also just install a jumper between the bushing lug and the grounding bus.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Through the conduit? I don't think I said that.
Here's a open bottom switchboard with a bonding jumper for all of the conduits to the EGC bus. Yes the jumper is too small because it's the wrong size size.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Ok.. misunderstood. So if I'm understanding this correctly there might be a way for us to get out of I stalling MIGB's at every pull box? If all the conduits originated at the same switchboard we can install them there and run from the bushing to the bus?Through the conduit? I don't think I said that.
Here's a open bottom switchboard with a bonding jumper for all of the conduits to the EGC bus. Yes the jumper is too small because it's the wrong size size.
View attachment 2573192
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Is this MIGB thing part of the spec? They're normally not required in a pull box.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Are you pulling an EGC in each raceway? If so the note does not apply.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Exactly I saw that. We are note pulling the feeders. Just installing the conduits. But this is an exazmple of the circuit so look slike they are.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Since there is an EGC the bonding bushing would not be required according to the Note 12. you posted.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
So who's job is to know what type of bushing needs to be installed and convey thsat to field? PM or foreman or both?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Well hopefully the foreman has read the entire spec and has noted what is and isn't required. The PM can also remind him. Then there's always the issue of we're not doing that and it gets purposely ignored.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
So formen should read entire electrical spec relevant to his work?
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Of course otherwise he's relying on the project manager or someone else to tell him everything that is required. If he doesn't read it then it's easy for him to point fingers at the PM when something is not followed.
As an aside, years ago we built a new Broadway theater. The spec called for all AV receptacle circuits to be IG with an EGC two trade sizes larger than the branch circuit (they pulled 12/2 MC). There was a full page detail of all of this circuiting, IGs, transformer wiring, etc. When the job was just about done I was left there to finish up the punch list. The engineer asked about the AV detail and I said what detail? They pulled out the detail drawing and in 2.5 years on the job that was the first time I had ever seen it. Seems that the PM told the general Forman that were not doing that and that it was removed from the job. Fast forward six weeks and I'm still there with a crew turning normal AV circuits to IG's.
Alwayslearningelec
Senior Member
- Location
- NJ
- Occupation
- Estimator
Wow!!!!
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Yup Wow. And the boss wanted to know why guys were still on a job that was "done". This is what they left us and where we had to find the IG's.
- Location
- Illinois
- Occupation
- retired electrician
Always...the estimators and project managers don't really have time to see all of the details that if missed can cost a substantial amount in the retofit but would have been a small amount at the time of the original construction.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
I agree, the foreman is on the front line of the job being in the field all day and he needs to know exactly what the client is paying for. I've done many jobs where the PM or super would say we're not doing that even if it's in the spec. At least at the end of the job they cannot blame the foreman if he asked the question.