BackCountry
Electrician
- Location
- Southern California
- Occupation
- Licensed Electrician and General Contractor
I’m getting lost a little bit on separately derived system bonding and grounding, hoping for some help.
Scenario: single phase 120/240 service @ 400A, two 200A disconnects, all located outside on a panel board at the entrance to a ranch. One disconnect is feeding a 120/240x480v step up 50kva transformer, with a 800 foot 4/0AL feeder (two conductors plus ground), into another 120/240x480v step down transformer which feeds an automatic transfer switch with batteries/solar as the standby energy source.
No neutral needed between the transformers obviously; however, what I’m confused on is whether I bond the neutral and ground together at the transfer switch (it’s service rated) or only bond at the 400A panel and meter like I normally would, and treat everything else downstream as a sub panel along with a ground rod at each separate building.
If the neutral forming transformer in the automatic transfer switch wasn’t involved, I wouldn’t feel so confused I suppose, thanks for any help you may have.
Scenario: single phase 120/240 service @ 400A, two 200A disconnects, all located outside on a panel board at the entrance to a ranch. One disconnect is feeding a 120/240x480v step up 50kva transformer, with a 800 foot 4/0AL feeder (two conductors plus ground), into another 120/240x480v step down transformer which feeds an automatic transfer switch with batteries/solar as the standby energy source.
No neutral needed between the transformers obviously; however, what I’m confused on is whether I bond the neutral and ground together at the transfer switch (it’s service rated) or only bond at the 400A panel and meter like I normally would, and treat everything else downstream as a sub panel along with a ground rod at each separate building.
If the neutral forming transformer in the automatic transfer switch wasn’t involved, I wouldn’t feel so confused I suppose, thanks for any help you may have.
