Non-service rated transferswitch ahead of service disconnect

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hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
We have a customer that has a lot of these at their different locations, non-fused 2000 amp 480 volt 3 pole transferswitches fed straight from the poco transformer, then to the service disconnect(s). Apparently it legal, as they have a lot of facilities like that, just trying to figure out where in code it is allowed? Is it because it’s not the service disconnect? Quoting the changeout of one, and don’t want to be tagged by the inspector without documentation saying it’s allowed.
 
Is it customer equipment or POCO equipment?

On rural services, particularly single phase 200 and 400 amp but think I have occasionally seen some thee phase, POCO often places a unit with meter and double throw non fused switch. Customer does pay for it and essentially owns it, but POCO provides and installs it. I have one serving my place. They sell them for less than I could ever purchase a service 200 amp manual transfer for myself let alone marking it up for a customer. They are not listed.

This is picture of what is typically seen. Also typical to see a 400 amp version with CT's in the meter section and of course they use a low current meter instead of 200 or 320 class meter.

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kwired said:
Is it customer equipment or POCO equipment?

On rural services, particularly single phase 200 and 400 amp but think I have occasionally seen some thee phase, POCO often places a unit with meter and double throw non fused switch. Customer does pay for it and essentially owns it, but POCO provides and installs it. I have one serving my place. They sell them for less than I could ever purchase a service 200 amp manual transfer for myself let alone marking it up for a customer. They are not listed.

This is picture of what is typically seen. Also typical to see a 400 amp version with CT's in the meter section and of course they use a low current meter instead of 200 or 320 class meter.

View attachment 2554602
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I’ve seen those on poultry farms.This is customer owned and installed automatic, all of the “new” retrofit ones I have done, have been motorized breaker type with oc protection on the utility side, and molded case switch on the generator side. But these are the solenoid knife type with no ocp.
 
texie said:
Then this is in no way compliant or safe. ATSs have to have OCPD or be service rated. Also worth noting that the selection of OCPD is very specific and will be detailed in the ATS docs. Especially in this size range.
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That’s why I’m hesitant to go back with what they already have, if not legal, they have gotten away with it in quite a few states. They are a very large nationwide company. They will probably have a cow when they find out the right switch is double the cost of the wrong one! LOL!
 
hillbilly1 said:
That’s why I’m hesitant to go back with what they already have, if not legal, they have gotten away with it in quite a few states. They are a very large nationwide company. They will probably have a cow when they find out the right switch is double the cost of the wrong one! LOL!
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The big problem here, among others, is the AIC rating of an ATS is dependent on very specific OCPDs in their listing. In my view, this is a serious safety and code problem.
 
hillbilly1 said:
That’s why I’m hesitant to go back with what they already have, if not legal, they have gotten away with it in quite a few states. They are a very large nationwide company. They will probably have a cow when they find out the right switch is double the cost of the wrong one! LOL!
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Unless there is an AHJ that will not allow it, they possibly just go with a contractor that will put in what they want??
 
texie said:
Here is a Cummins white paper on this subject: https://www.cummins.com/sites/defau...L 1008 ATS Withstand and Close On Ratings.pdf
Also CSE magazine has had a number of articles on this over the years that you could Google.
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Thanks! We may lose the bid to another contractor who will do it, but from a liability standpoint, I’m not taking the chance of using the non protected switches. Don’t know who they previously used, but they seemed to put a lot of those in. May be why they got them because they were a whole lot cheaper, and the customers engineers looked the other way! LOL!
 
Boss finally called the inspection department, they had a whole laundry list of things they wanted including a detailed stamped set of drawings. So like it or not, the customer is likely to pony up for the service rated switch! LOL!
 
hillbilly1 said:
Boss finally called the inspection department, they had a whole laundry list of things they wanted including a detailed stamped set of drawings. So like it or not, the customer is likely to pony up for the service rated switch! LOL!
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I think that is wise to get engineered and sealed drawings for something this large. What were they doing for GFPE on the existing? You may also want to consider a separate main as opposed to a service rated ATS for a number of reasons. Gonna take some reworking to get the main bonding jumper and grounding rearranged. Does the existing main have a removable MBJ?
 
No too big of a deal, in fact, they don’t have any existing bonding in the switch presently. The customer was saying to be careful on opening up the switch, as they have been shocked before by it. They are using the six switch rule on the gear to get out of using GFPE. (two mains) Don’t know yet if they correctly pulled an equipment ground to the buildings, or if the gear itself is bonded. Gear is nippled into the side of the transferswitch. It would be cheaper to get a service rated switch than to do all the work required to add a main.
 
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