I need to pull six 10AWG circuits from my panelboard up to a 24x24 in one pipe and all circuits require an iso ground. Does each circuit need its own dedicated iso or can I get away with pulling only one and splicing off it in that 24x24 and would I have to upsize it? Can’t seem to find it in the code.
Iso Ground
- Thread starter JayBuud
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
The NEC doesn't care how you install isolated ground conductors so you could pull a single IG for all of the circuits within the raceway. The designer may prefer one for each circuit but that is not required for code compliance.
Edit: what Augie said. IGs are so useless I wouldn't pull more than one unless so directed
Edit: what Augie said. IGs are so useless I wouldn't pull more than one unless so directed
My favorite part of IGs is when they get specified for a POS system which ends up being a tablet with a 1-15P USB adapter.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
In the last 15 years that's the only place where I've seen them used. It was for two POS cash registers. I asked the foreman how we were going to use IG's when we had no provisions for them in any panel. He just put an orange IG receptacle in and bonded it to the box. Worked just fine.
electrofelon
Senior Member
- Location
- Cherry Valley NY, Seattle, WA
- Occupation
- Electrician
I
Over the oast few years ive hooked up a dozen ICPMS's (inductively coupled plasma Mass spectrometer) for my client. I happen to read through the manual kind of recently and noticed they we're supposed to have IGS. Opps. They're all working totally fine.In the last 15 years that's the only place where I've seen them used. It was for two POS cash registers. I asked the foreman how we were going to use IG's when we had no provisions for them in any panel. He just put an orange IG receptacle in and bonded it to the box. Worked just fine.
It always comes from the kitchen consultant, seems to just be boilerplate text from many decades ago.
Oh no! 406.3(E)(1) (2023).He just put an orange IG receptacle in and bonded it to the box. Worked just fine.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
What's wrong with an orange IG receptacle?
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
What exactly are the provisions in a panel for an IG?
- Location
- Illinois
- Occupation
- retired electrician
If the panel is the first panel after a SDS, nothing is needed. If the panel is supplied by another panel, there will be a second feeder equipment grounding conductor connected to an isolated equipment grounding terminal bar.
Note, this is for when you are making the isolated equipment ground a real isolated equipment grounding system where the isolated conductor originates at the system or main bonding jumper, which ever may apply.
ggunn
PE (Electrical), NABCEP certified
- Location
- Austin, TX, USA
- Occupation
- Consulting Electrical Engineer - Photovoltaic Systems
If all the isolated grounds connect to the same point, are they really isolated?
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
Isolated ground bar in the panel with an iG conductor run either back to the service neutral where the MBJ is installed or directly to the X0 of a transformer.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Yes. They are single ended circuits so no ground loop is created.
- Location
- Illinois
- Occupation
- retired electrician
The intent is that they be isolated back to the main or system bonding jumper whichever you hit first.
While lots of companies that make electronic equipment wanted an actual isolated ground that was not connected to the electrical system, you can't do that because the isolated EGC is still the fault clearing path and must connect back to the source so faults can be cleared.
It probably should have been named insulated ground and not isolated ground.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
So just a bar, like the neutral bar, with plastic insulators?
- Location
- Illinois
- Occupation
- retired electrician
Yes, exactly the same as an neutral bar.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Or, even dedicated ground.
The concept was for the ground at the end/outlet to be isolated from other EGCs except at the source of the circuit.
Not much in the code, if its datacenter / telcom usually your contract will specify following IEEE Std 1100 and or other ANSI/TIA documents.
The reason its specified is in some equipment the difference between a 1 and 0 is a volt or even mili volts, stray currents can elevate the electrical ground plane by a volt flipping a 1 to a 0, corrupting data.
herding_cats
Senior Member
- Location
- Kansas
- Occupation
- Mechanical Engineer
You would need two grounds. One isolated and one not. The 24x24 need the non IG, but the the load side need isolated or dedicated back to the panel. The idea of IG is that it is not reliant to case grounding on boxes, and other areas that might fail ground connections.