Adding a ground bar to a 480 volt main distribution feeder panel.

[Danny89]

I want/need to add a ground bar to a 480 volt panel that is feed by a 600 amp main circuit breaker... What is the rule of thumb for adding ground bar to panels? Is there amperage requirements or standards to adhere to before installing a ground bar to this panel photos attattched

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[electrofelon]

Easiest thing is to get one from Siemens and it will come with the correct screws to go right into the existing holes. If I have to retrofit one, I will drill and tap 8-32 threads into the cabinet.

 

[Cow]

We buy those Siemens panelboards all the time.

Like Electro said, go to your siemens rep and ask for a ground bar or two for a panelboard, not a loadcenter. It'll be the type that comes wrapped in white paper, not in a clear plastic bag.

 

[kwired]

I think OP might have concern over the current carrying ability of the bar being installed. My thought is if you put in a bar that only accepts 4 AWG maximum conductors in any port, it will have enough cross sectional area that it will carry anything a 4 AWG conductor can bring to it and the fact it is installed at a 600 amp panelboard means very little.

If you need to terminate a larger conductor you will be getting a bar with larger ports - but to accommodate those that bar will physically be larger and will be able to handle any current the larger conductor can deliver to it.

 

[Strathead]

I think OP might have concern over the current carrying ability of the bar being installed. My thought is if you put in a bar that only accepts 4 AWG maximum conductors in any port, it will have enough cross sectional area that it will carry anything a 4 AWG conductor can bring to it and the fact it is installed at a 600 amp panelboard means very little.

If you need to terminate a larger conductor you will be getting a bar with larger ports - but to accommodate those that bar will physically be larger and will be able to handle any current the larger conductor can deliver to it.

My thought also.

 

[electrofelon]

Even the bars that only have holes for #4 you can get those add on lugs that usually go up to 2/0 I think (thinking of square d stuff). I guess we are to assume that whatever fits is ok IIRC those siemens panelboard ground bars have many larger than #4 holes.

 

[Cow]

I think OP might have concern over the current carrying ability of the bar being installed.

Yep, I totally missed what he was asking. I read what I thought he said, rather than what he actually said.:ashamed1:

IIRC those siemens panelboard ground bars have many larger than #4 holes.

You're right, there are several holes rated for 1/0 mixed in with the smaller ones.

 

[kwired]

Cross sectional area of said ground bar isn't as critical as it is for a wire conductor, especially an insulated wire conductor that normally carries current.

EGC may carry thousands of amps during a ground fault, but only has to do so for long enough time to clear the OCPD, and can take more temp rise than the insulation on a wire conductor on top of that, but at same time is short in length so you don't have the resistance you might have over many feet of a wire conductor either.