# ATS testing



## Wirenuting (Sep 12, 2010)

heavyduty73 said:


> We currently have a handful of ASCO 7000 series ATS's that we test monthly by putting it manual bypass and testing the switch operation itself without actually switching the load of the switch. My boss has been told by someone that we should testing it with load transfer instead rather then in bypass. What are your thoughts on this? The manual explains how to test in both bypass and non bypass conditions but doesn't say what is preferred. It is in a healthcare setting which is why we do it in the bypass mode. Are the any code or standards that cover this?


Look in the hospital facilities handbook.
I always tested mine under load. How else do you know it will work? We had 22 ATS's and each bi-weekly test I would use a different one to start the test. This way the start circuit was also tested. One a random basis I would pick a switch and let it cycle thru a 30 min test alone. Once a year I had a load banking done. 
I was able to shift loads each bi-week test allowed me to shift the main load between each of 3 generators. This helped prevent wet stacking. 

The load banking was important to keep the gens clean. It also allowed us to find a hidden issue once. We had a first start behind a false wall up in the operating room area. The roofing tar had heated enough that it oozed down the wall and caught fire. Only my insistence to have the load bank found it. 
The operating rooms and ICU were the only 2 ATS's that I had to be careful testing. I didn't like to use them while people were on the table. 

Because we had a high equipment load on our pri-2 circuit, I installed a phase loss monitor on the line side of that ATS. This allowed an automatic load shedding if there was an outage during a bi-weekly test. I had it tied to the MCC master board and PLC / building automation system. 

30% I think was the minimum load I would pit each one and we tested for 2 hours minimum each time. 
Also check your fuel. If you use diesel fuel it's best to use bunker diesel. It has the additives for long term storage. Keeps your fuel from getting algae. Don't always trust your Veder Root monitor system. Dip the tank with a coated fuel stick. 
After you run them long enough you will learn to feel when they are running right. The inspectors from the Joint Commision will listen and believe you when you talk to them about your emergency system. They can pick out a BSing boss from a mile away. 
They can feel your ownership when they ask what is the best day to be operated on. My answer was always on a Tuesday, because that is when I tested the generators. No 10 second wait and I would always be there just in case.


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## Zog (Apr 15, 2009)

heavyduty73 said:


> We currently have a handful of ASCO 7000 series ATS's that we test monthly by putting it manual bypass and testing the switch operation itself without actually switching the load of the switch. My boss has been told by someone that we should testing it with load transfer instead rather then in bypass. What are your thoughts on this? The manual explains how to test in both bypass and non bypass conditions but doesn't say what is preferred. It is in a healthcare setting which is why we do it in the bypass mode. Are the any code or standards that cover this?


There is the ANSI standard (MTS-2007) and NETA testing standard for ATS testing, which includes 18 electrical tests that are required to be performed. Otherr specs that apply include ANSI/NFPA 110, IEEE 602, IEEE 446. Everything in those are covered under the ANSI/NETA MTS.


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## Bbsound (Dec 16, 2011)

Wirenuting said:


> Look in the hospital facilities handbook.
> I always tested mine under load. How else do you know it will work? We had 22 ATS's and each bi-weekly test I would use a different one to start the test. This way the start circuit was also tested. One a random basis I would pick a switch and let it cycle thru a 30 min test alone. Once a year I had a load banking done.
> I was able to shift loads each bi-week test allowed me to shift the main load between each of 3 generators. This helped prevent wet stacking.
> 
> ...


 This is good info, in line with the almost 100 hospital transfer switches I am involved with.


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## Tasjr (Dec 9, 2011)

Also keep in mind if these are closed transition switches you should not have to worry about load interruption. Assuming of course the rest of the equipment is in good condition.


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