320 amp service

[Lazy]

Hi
when installing two (2) 200 amp load centers would you run a ground wire from each load center neutral to the ground rod or connect a ground wire to the neutral in the meter socket box to the ground rod?

Charlie.

 

[mahlers]

Assuming your load panels are close together, you can bond the neutral to ground in a number of acceptable ways. Personally, I bonded neutral to ground in each separate panel, and drove two ground rods about ten feet apart. I ran separate #4 bare copper wire from each panel to the ground rods. Since both panels share the same neutral from the pole, this should give you a little bit better ground than just one ground rod. Over here, you also need to bond the ground to the water pipe entrance to your house. That seems a little silly to me since most of my water pipes are PVC - but go figure... The inspectors have the final say.

I believe you can also just bond the two panels together and run a single ground line to a single ground rod.

While you're at it, give some thought to installing panel-mounted surge and lightning arrestors. It will add a couple hundred bucks total to the install, but it's a great thing to have when you get power surges and/or lightning strikes. Whole-house protection just can't be beat. Check out Delta Surge Supressors and Lightning Arrestors - they mount easily to your panel via conduit knock-outs.

 

[ericinmich]

Another idea (ie. something that I wished I would of done).

I have two 200 amp services at my house. I wanted/needed a backup generator so I found a decent midsized solution. 18KW with a 200 amp switch. It now switches and provides backup power to one of the panels.

Of course, I wish that I would of planned out the circuits between the two. Now I need to move about 8 to 10 from one panel to the other to provide the power to the desired circuits...

 

[schmism]

Personally, I bonded neutral to ground in each separate panel, and drove two ground rods about ten feet apart.

It was my understanding that this was NOT the perfered way to wire it as you run into a ground loop issue.

I believe you can also just bond the two panels together and run a single ground line to a single ground rod.

It was my understanding that this was the correct way to wire it. The above (single) ground rod would service both the meter box, and both 200amp service pannels.



As my meter is more than 15' away from my "breaker box" (mounted on a pole) i was required to provide a seperate disconnect at the pole (just a 200amp breaker) with a ground rod for the meter box. A second ground rod is/was required for the "breaker box" at my barn. (as this "breaker box" is now considered a sub pannel of the main disconnect on the pole)

 

[tallyho8]

When I installed the meter panel/breaker box in my barn, they made me use two ground rods 8' apart and run one continuous ground wire from the box to both rods.

 

[SnowRidge]

If you have multiple ground rods, they should be tied together with bare copper underground. It's not important how deep it is, unless code says otherwise, just so it is underground. This helps protect against lightning strikes. If the ground rods are not bonded together, a lightning strike can generate a damaging differential voltage between the grounds that will feed back into your system.

In lightning country, all ground rods should be tied together this way. That includes the telephone and TV/satellite antenna grounds.

I use #6 bare copper.

 

[schmism]

If the ground rods are not bonded together, a lightning strike can generate a damaging differential voltage between the grounds that will feed back into your system.

also known as a ground loop.