Service Rated ATS-No Generator

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Service Rated ATS-No Generator

I haven't taken the time to read the code specifics on this, but a friend of mine is a partner in a giant generator sales/install company. For residential, they are installing 200A ATS's connected to 20kw and less generators with wireless load-shedding relays that connect directly to the appliance, which makes me think there is no issue with the setup described in the OP. He said they are going to install interlocks, so I don't see a difference.

What we've been doing for a setup like this is to install Kirk key interlocks and run a feeder to a generator tap-box. Square D makes a 600A and 800A tap box.

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brantmacga said:
I haven't taken the time to read the code specifics on this, but a friend of mine is a partner in a giant generator sales/install company. For residential, they are installing 200A ATS's connected to 20kw and less generators with wireless load-shedding relays that connect directly to the appliance, which makes me think there is no issue with the setup described in the OP. He said they are going to install interlocks, so I don't see a difference.

What we've been doing for a setup like this is to install Kirk key interlocks and run a feeder to a generator tap-box. Square D makes a 600A and 800A tap box.
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But he is installing complete systems.

Installing an interim, incomplete system with questionable compliance issues is what we are discussing here.
 
brantmacga said:
I haven't taken the time to read the code specifics on this, but a friend of mine is a partner in a giant generator sales/install company. For residential, they are installing 200A ATS's connected to 20kw and less generators with wireless load-shedding relays that connect directly to the appliance, which makes me think there is no issue with the setup described in the OP. He said they are going to install interlocks, so I don't see a difference.

What we've been doing for a setup like this is to install Kirk key interlocks and run a feeder to a generator tap-box. Square D makes a 600A and 800A tap box.

Sent from my iPhone using Tapatalk
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I did not see anything like that from infinity.
And any interlocks discussed (in addition to the ATS itself?) were not in the context of load shedding.
 
GoldDigger said:
I did not see anything like that from infinity.
And any interlocks discussed (in addition to the ATS itself?) were not in the context of load shedding.
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Yeh I misread that ..... he was saying "like an interlock"


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infinity said:
Yes in this case the service rated ATS would be 200 amps and feed a 200 amp panel. I believe that I omitted that part.
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I kind of assumed you wouldn't run any more capacity on the "generator side" of the transfer switch then the largest generator you intend to connect to it can deliver. How many homes have a 200 amp service and a standby generator capable of delivering 200 amps, whether manual or automatic transfer or if there is load shedding or not? Unless there is electric heat, often a generator capable of delivering 50 amps may be a little borderline on occasion but get around 75 or 80 amps of supply ability and you can run most homes with no intentional load shedding necessary.

jap said:
The issue then is not the ATS, its what wiring is put in place at this point to connect the generator to the ATS.

If I had to run something outside for a quick connect, and didn't want to have to change anything in the future, I don't know what, if anything, would deter me from running full size to the inlet connection point.

But that's just me.



JAP>
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Why run a 200 amp conductor to a standby source that can only deliver 5kVA, 10kVA or even up to 25 kVA?
 
kwired said:
I kind of assumed you wouldn't run any more capacity on the "generator side" of the transfer switch then the largest generator you intend to connect to it can deliver. How many homes have a 200 amp service and a standby generator capable of delivering 200 amps, whether manual or automatic transfer or if there is load shedding or not? Unless there is electric heat, often a generator capable of delivering 50 amps may be a little borderline on occasion but get around 75 or 80 amps of supply ability and you can run most homes with no intentional load shedding necessary.

Why run a 200 amp conductor to a standby source that can only deliver 5kVA, 10kVA or even up to 25 kVA?
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Your stuck in House mode and assuming a lot since you don't know if this scenario may not be for a house or what the load will be on the Xfr Switch at this time.

If I'm installing a 200 amp transfer switch and don't want to redo anything in the future because I'm not sure what load I'm going to put on it or what size generator I'm going to connect to it, I'd run 200 amp rated conductors to the attachment point at this time.



JAP>
 
jap said:
Your stuck in House mode and assuming a lot since you don't know if this scenario may not be for a house or what the load will be on the Xfr Switch at this time.

If I'm installing a 200 amp transfer switch and don't want to redo anything in the future because I'm not sure what load I'm going to put on it or what size generator I'm going to connect to it, I'd run 200 amp rated conductors to the attachment point at this time.



JAP>
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OP isn't installing the permanent generator that will interface with the ATS at this time, doesn't matter if it is residential or not. Apparently whatever generator is going to be used for the time being doesn't deliver more then 50 A, and the reason to use a 50 amp inlet device. When a permanent genset is installed it may not even be placed anywhere near the 50 amp inlet location either.
 
kwired said:
OP isn't installing the permanent generator that will interface with the ATS at this time, doesn't matter if it is residential or not. Apparently whatever generator is going to be used for the time being doesn't deliver more then 50 A, and the reason to use a 50 amp inlet device. When a permanent genset is installed it may not even be placed anywhere near the 50 amp inlet location either.
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And how do you know that?
 
kwired said:
OP isn't installing the permanent generator that will interface with the ATS at this time, doesn't matter if it is residential or not. Apparently whatever generator is going to be used for the time being doesn't deliver more then 50 A, and the reason to use a 50 amp inlet device. When a permanent genset is installed it may not even be placed anywhere near the 50 amp inlet location either.
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Never mind.

Go ahead and install your 50 amp wiring from an inlet to the 200 amp Auto Transfer switch so in the future when they want more power from a larger generator they can redo everything they installed originally which is exactly what the 1st post indicated they did not want to do.

JAP>
 
kwired said:
OP isn't installing the permanent generator that will interface with the ATS at this time, doesn't matter if it is residential or not. Apparently whatever generator is going to be used for the time being doesn't deliver more then 50 A, and the reason to use a 50 amp inlet device. When a permanent genset is installed it may not even be placed anywhere near the 50 amp inlet location either.
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Correct.

The OP indicated they didn't want to have to reconfigure the service when they decided on the "Future" generator.

It would be best not to install anything from the Transfer switch to the inlet at this time if you didn't have to, but, if you do, and you don't want to have to change anything when the future generator gets there, whatever size that may be, my question would be why would you not install full size conductors to the generator side of the X-fr switch to the inlet at this time?

JAP>
 
jap said:
Correct.

The OP indicated they didn't want to have to reconfigure the service when they decided on the "Future" generator.

It would be best not to install anything from the Transfer switch to the inlet at this time if you didn't have to, but, if you do, and you don't want to have to change anything when the future generator gets there, whatever size that may be, my question would be why would you not install full size conductors to the generator side of the X-fr switch to the inlet at this time?

JAP>
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How many generator installs do you see same size standby side conductors as service entrance conductors other then when entire service is backed up and the total load is near total service capacity? services for a fixed load like a pump station or a communications tower are probably the main exceptions. Even a hospital or other place with legally required standby systems don't necessarily back up the entire service capacity, just the legally required loads plus an additional desired optional loads.

Now most of my comments were sort of based on typical home or small business ATS systems, and the assumption was this was a service rated ATS, what the OP didn't want to have to change when the customer gets a generator is the service disconnecting means. The 50 amp circuit to the "inlet" was likely a short run, maybe even just a nipple to a inlet receptacle right next to the ATS. Not that much to redo when a genset that compliments the ATS is finally installed yet still allows one to bring some portable generator if needed with little hassle before a permanent one is installed.

I did a fairly large home (especially for around here) about 10 years ago. Owner made it pretty clear he wanted an automatic generator some point down the road. He had a lot of electric heat in this house (50kW just in the house, and another 10 in the garage). We had decided he wouldn't be getting a generator that would run everything. I also had four service entrance panels in this house as it cost less then a single disconnect and taps to four panels. We decided to put everything we may want backed up into one panel. But I put a single breaker enclosure as the service disconnect and left some space so an ATS could be inserted with little troubles between it and the panel it fed should he ever get the generator.

Now about 10 years later, he has never had a power outage that wasn't restored within a few hours, and has never installed the generator yet. I bet he will if ever out for any lengthy period though, only to go at least another 10 years before he truly needs it again:blink:
 
kwired said:
How many generator installs do you see same size standby side conductors as service entrance conductors other then when entire service is backed up and the total load is near total service capacity? services for a fixed load like a pump station or a communications tower are probably the main exceptions. Even a hospital or other place with legally required standby systems don't necessarily back up the entire service capacity, just the legally required loads plus an additional desired optional loads.

Now most of my comments were sort of based on typical home or small business ATS systems, and the assumption was this was a service rated ATS, what the OP didn't want to have to change when the customer gets a generator is the service disconnecting means. The 50 amp circuit to the "inlet" was likely a short run, maybe even just a nipple to a inlet receptacle right next to the ATS. Not that much to redo when a genset that compliments the ATS is finally installed yet still allows one to bring some portable generator if needed with little hassle before a permanent one is installed.

I did a fairly large home (especially for around here) about 10 years ago. Owner made it pretty clear he wanted an automatic generator some point down the road. He had a lot of electric heat in this house (50kW just in the house, and another 10 in the garage). We had decided he wouldn't be getting a generator that would run everything. I also had four service entrance panels in this house as it cost less then a single disconnect and taps to four panels. We decided to put everything we may want backed up into one panel. But I put a single breaker enclosure as the service disconnect and left some space so an ATS could be inserted with little troubles between it and the panel it fed should he ever get the generator.

Now about 10 years later, he has never had a power outage that wasn't restored within a few hours, and has never installed the generator yet. I bet he will if ever out for any lengthy period though, only to go at least another 10 years before he truly needs it again:blink:
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With the information we have received on this scenario you answered my reasoning for installing full size conductors from the Transfer Switch to the inlet location in your very 1st sentence above.

That's the whole point.

Without knowing all the details, which we don't, or , knowing what the load is going to be, which we don't, or what size generator is going to roll up, which we don't, or what the backup system is going to be used for, which we don't, to me the only way to cover all the bases would be to pull full size conductors to the connection point.

That would be, in my mind the only way you would not have to change anything in the future.

Now if we're going to speculate and go with the norm, and let the cost decide what they are going to do instead of what it would actually take to cover all the bases, I'm with you,


JAP>
 
All of the details are there but I realize that the thread is long so it's easy to miss something. Here's the summarized version:

My friend is upgrading his service to 200 amps and wants to install a SR ATS/200 amp subpanel so that in the future he can install a whole house generator. For now he will use his portable generator with a 50 amp inlet mounted on the outside of the house which feed the EM side of the ATS. Instead of using an interlock kit on the panel he will use the ATS manually when the power goes off to transfer to the inlet. Various CB's will be turned on just like when using an interlock kit.

In the future all of the associated inlet wiring and inlet will be removed and the generator wiring installed in its place.
 
infinity said:
All of the details are there but I realize that the thread is long so it's easy to miss something. Here's the summarized version:

My friend is upgrading his service to 200 amps and wants to install a SR ATS/200 amp subpanel so that in the future he can install a whole house generator. For now he will use his portable generator with a 50 amp inlet mounted on the outside of the house which feed the EM side of the ATS. Instead of using an interlock kit on the panel he will use the ATS manually when the power goes off to transfer to the inlet. Various CB's will be turned on just like when using an interlock kit.

In the future all of the associated inlet wiring and inlet will be removed and the generator wiring installed in its place.
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What a kill joy.
That leaves us nothing to discuss. :)

JAP>
 
infinity said:
My thought as well but I love to hear the opinions (hence this thread) of other professionals (even those who don't agree with me) who may have a different take on the installation. By doing so you can gather background information so there is less of a chance of being surprised when proposing the question to the AHJ. :cool:
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My position on this, if I understand it correctly is this:

I was fully prepared and started typing a disagreement with doing this, and typed myself right around to not seeing where there would be any code violation at all. After arguing against myself I feel this is no different than having a bunch of empty breaker spaces and saying you have to "protect" the homeowner from hooking too many things up so you have to up size the service.
 
infinity said:
Is there any potential code issue with using a service rated ATS with a 50 amp inlet box for the EM feeder in lieu of a generator? Money is tight but they want to have the option to add a generator in the future without having to reconfigure the service.
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If I'm completely blunt about this, I think your setup is golden compared to what most home owners do which is run to the big box store, buy a noisy 5kw generator, have their buddy at the coffee shop who seems to know everything there is to know about electricity make up a "110" or "220" volt suicide cord out of a piece of 12/2 NM and backfeed the dryer outlet.

JAP>
 
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