Optional Standby Gen ATS

Status
Not open for further replies.
ron

ron

Senior Member
Location
New York, 40.7514,-73.9925
Considering 702.6, does a transfer switch need to be listed as a transfer switch?
There are circuit breaker type transfer pairs that are available but not always listed UL1008 as an ATS.
 
702.6 does not require transfer equipment to be listed or even labeled as such. However, 702.4 does require equipment be approved for the intended use.
 
I can say with experience :wink: that as an inspector, listing is important...not the end all, but important enough that I will choose a listed product as much as is possible. For generators in general, I would like to see a listed product, unless the nonlisted product really does what a listed product can.

The UL White Book has some interesting info in it as well, regarding this topic. Also, listed transfer equipment is readily available, so it is not a hardship for one to find a piece of equipment that will fit the bill of what they are looking for. From the bottom line to the very technical equipment.
 
Pierre,
As you could imagine, I was asking the question for an oddball application.
I cannot locate a UL 1008 listed ATS for 5000A 4 pole @ 200kAIC. I can however get a ABB circuit breaker pair with the needed CB listings and couple it with an ASCO or Russelectric transfer switch controller, which will do the function, but not be listed as an ATS.
 
ron said:
Pierre,
As you could imagine, I was asking the question for an oddball application.
I cannot locate a UL 1008 listed ATS for 5000A 4 pole @ 200kAIC. I can however get a ABB circuit breaker pair with the needed CB listings and couple it with an ASCO or Russelectric transfer switch controller, which will do the function, but not be listed as an ATS.
Click to expand...



Not a spot I would want to be in if I were you.

What about calling the ATS folks and see if they have run into this prior. Maybe they have a good answer.
If you do that and they have an answer, please let us know what it is.
Thanks
 
At this point they (all of the ATS folks) say that the equipment (regular ATS or CB transfer pair) is not available in 5000A, 4P, 480V, 200kA with a UL 1008 listing. 100kA yes, but 200kA no.
Since I can't get one with an ATS listing at that size, I am going to try and break up the downstream loads into smaller pieces.
 
Ron,

What is the maximum size the ATS manufacturer's can UL list @ 200KA, I like your idea of breaking up the down stream if you can, add two ATS @ 2500A then feed those to your down steam. Give Cuttler-Hamer a call, they may be able to do it using breakers.
 
I've spoken with Square D, Eaton, ABB, ASCO and RussElectric. The information listed in the previous posts pertain to all of them.

They have series listings for 4000A switches (also listed as an ATS) up to 200kA, but not 5000A 4P. They can give me 5000A, 3P at 200kA but not 4P. Just not tested yet.
 
ron said:
... and if you were the AHJ, what would you approve for the intended use.
A CB is for overcurrent protection, not necessarily operation of a source transfer.
Click to expand...

A very common and allowed, listed system is a kirk key set up used with circuit breakers, feeding a common buss.
 
Tom,
I agree that it happens manually with kirk keys, and could be made automatic. Since UL 1008 exists, I'm worried that an AHJ may not think that I am not using a transfer pair as its intended use if it is not listed to UL 1008.
 
Status
Not open for further replies.
Top