I'm installing a generator/ATS for a wastewater treatment plant and had a couple of questions. The ATS will be mounted next to the 400A main service disconnect on the outside of the building, which all of the GEC's terminate in. The service disconnect feeds the main distribution panel directly behind it inside of the building. How do I bond the generator grounded conductor in the ATS, and could I run the "load" from the ATS back through the main disconnect and to the MDP through the existing conduit? Any thoughts appreciated!
ATS bonding
- Thread starter Danger32
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If you are keeping the existing service disconnect then the transfer switch grounding and bonding looks like a sub-panel.
Line and load conductors can snuggle up in the same conduit and keep each other company all the time, except for the service conductors; they are segregated from all the other conductors and remain alone. It's the price they pay for being unfused.
Line and load conductors can snuggle up in the same conduit and keep each other company all the time, except for the service conductors; they are segregated from all the other conductors and remain alone. It's the price they pay for being unfused.
antenna2001
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Years ago I worked on a symilar system and I made some notes for myself to make it easier to find the information again when I needed it. Although I am not sure that they apply directly to your system, check the following sections of the NEC:
250.24(A)(3)
250.30(A)(1)(Exception 1)
I remember that the tricky part was to make sure that a SINGLE system bonding jumper connection was permitted and that it had to be made at the tie point, that is, at the point where the grounded circuit conductors from the alternate sources met.
250.24(A)(3)
250.30(A)(1)(Exception 1)
I remember that the tricky part was to make sure that a SINGLE system bonding jumper connection was permitted and that it had to be made at the tie point, that is, at the point where the grounded circuit conductors from the alternate sources met.
The key, I believe, is if the ATS switches the neutral. If the neutral is not switched, then the generator is not a SDS and neutrals and equipment ground must be kept separate with grounding conductors installed to all.
If the ATS does not switch the neutral, then it (the neutral) remains isolated except at your service disconnect.
If the ATS does not switch the neutral, then it (the neutral) remains isolated except at your service disconnect.
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