New service
- Thread starter mgarrett
- Start date
- Status
- Location
- Illinois
- Occupation
- retired electrician
Assuming that the transfer switch is located next to the service OCPD and is service rated I don't see an issue. The main bonding jumper would be in the transfer switch and the grounded and grounding conductors would have to be kept separate at the service OCPD.
The designer has the grounding and grounded conductors be bonded in the fused disconnect after the 4 pole double throw switch.
The 4 pole double switch would have to become a 3 pole so the grounding and grounded conductors good be bonded at the first location.
The 4 pole double switch would have to become a 3 pole so the grounding and grounded conductors good be bonded at the first location.
102 Inspector
Senior Member
- Location
- N/E Indiana
- Occupation
- Inspector- All facets
Could this be a utility requirement to remove all loads for the meter base before they might have to service it. Seems to me I have seen that on a couple services, but utility required.
The service disconnect needs to either be ahead of the ATS or integral to it.
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
Didn't we just have this discussion last week?
- Location
- Illinois
- Occupation
- retired electrician
But the service OCPD does not have to be ahead of part of the transfer switch.
But the transfer switch requires overcurrent protection.
- Location
- Illinois
- Occupation
- retired electrician
You can get service rated manual transfer switches that do not have built in OCPD. They serve as the service disconnect and the service OCPD is located next to the transfer switch.
The transfer switch requires overcurrent protection.
- Location
- Illinois
- Occupation
- retired electrician
Not if it is a service rated switch. The OCPD can be on the load side of a service rated switch.
Can you show where you are getting that from? Or show us a service rated transfer switch that does not come with integral overcurrent protection, or not require it in the utility source.
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
I was kind of wondering the same thing, but a quick check of the NEC reveals it. See 230.94 exception #1 for the clearest indication, but 230.91 give you a hint also
Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
"immediately adjacent to"
- Location
- Massachusetts
If you look in the UL general directory you will find that the listing allows for service rated ATS without integral OCPD.
But I don't know if any are available or not
Do you have a link?
smoothops10
Member
- Location
- FL
- Occupation
- EE
Based on the OP it sounds like it is a double throw safety switch installed not a manual transfer switch. A double throw safety switch typically only has a short circuit current rating of 10kA. While an MTS would have a WCR rating with* a breaker upstream. Without a breaker upstream, I don't think you would be permitted to install though I could be wrong.
- Location
- Illinois
- Occupation
- retired electrician
The UL Guide Information for Transfer Switches (WPTZ) provides for transfer switches without overcurrent protection.
smoothops10
Member
- Location
- FL
- Occupation
- EE
Without integral overcurrent protection.
And when it is provided without the integral overcurrent protection it must be marked 'When protected by'.. corresponding overcurrent protection etc.
Without anything upstream it would not be protected by anything and the transfer switch would have no rating I would think.
- Location
- Massachusetts
Sorry I was on the road when I posted that, I am home now and went looking and could not find what I thought I had seen. I did not remember correctly.
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