Read this first: http://www.mikeholt.com/Newsletters/ig2.htm
and: http://www.engineeringharmonics.com/papers/p_gupdte.htm
If you have a ground rod for your system that is seperate from your main ground you risk large ground potential differances if you have a lightning strike near by or have a ground fault condition on one of your grounds. The code requires that the grounds be tied together.
and: http://www.engineeringharmonics.com/papers/p_gupdte.htm
If you have a ground rod for your system that is seperate from your main ground you risk large ground potential differances if you have a lightning strike near by or have a ground fault condition on one of your grounds. The code requires that the grounds be tied together.