ATS without a generator

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Ponchik

Ponchik

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Location
CA
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Electronologist
Does an automatic transfer switch need a generator? here is the situation.

I have proposed a panel upgrade (200Amps) with a 200amp rated automatic transfer switch but the client will get the generator in about a year.

Does anyone see any problem with this installation?
 
Do they know what generator they are going to use? The transfer switches for home standby generators are not generic. I would not install the transfer switch until the generator is installed.
 
curt swartz said:
Do they know what generator they are going to use? The transfer switches for home standby generators are not generic. I would not install the transfer switch until the generator is installed.
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What do you mean they are not generic?

I was planning on a kohler, Winco, Onan or Zenith. Does the transfer switch have to match the manufacturer of the generator?

What do you see wrong or future problems with installing the ATS without the generator?

Thanks



Jumper,

The ATS is after the main 200A and before the load center.
 
As Curt mentioned, you can avoid a problem if you know what brand of generator is proposed and match that with your ATS. Different makes have components in the ATS or in the generator and the inter-connections are not universal.
Other than that you should not have a problem.
 
augie47 said:
As Curt mentioned, you can avoid a problem if you know what brand of generator is proposed and match that with your ATS. Different makes have components in the ATS or in the generator and the inter-connections are not universal.
Other than that you should not have a problem.
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So another words a Kohler transfer switch will not or may not work with a Winco generator.
How about the load center that have a built in ATS are those specific to a certain brand as well?
 
Just be sure to specify and install any generator that operates with a "two-wire" starting sequence. You can use an ABCO transfer switch which will work with any of the brands of generators you mentioned, provided that you get one configured for the 2-wire start.
 
Even if you put a switch in from another manufacture that works there is a good chance have you will have warrantee issues with the generator. Home standby units specify specific transfer switches to go with their generators. Either determine what generator is going to be used now or leave a space for the switch to be installed in the future.

Are you planning to connect all the loads of the building through the ATS? If so remember you will need to size the generator for the entire calculated load not just what the owner wants to be able to use.
 
Onan uses a three wire control while Kohler uses two wire, Generac controls the transfer switch from the generator (four to six wires) on their smaller units, some can be modifed to work, but then you get into warranty issues.
 
curt swartz said:
Are you planning to connect all the loads of the building through the ATS? If so remember you will need to size the generator for the entire calculated load not just what the owner wants to be able to use.[/FONT]
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well, you just threw a wrench into this plan :)

i didn't know this, i thought they can turn ON any of their loads that they want and let the breaker on the generator determine how much power they can use.

I guess we need to pick certain loads now or plan for a large generator that will handle the calculated load.

Thanks.
 
edward said:
well, you just threw a wrench into this plan :)

i didn't know this, i thought they can turn ON any of their loads that they want and let the breaker on the generator determine how much power they can use.

I guess we need to pick certain loads now or plan for a large generator that will handle the calculated load.

Thanks.
Click to expand...

That's 702.5(B)(2), if you're on 2008 yet. You can also consider load-shedding.
 
edward said:
well, you just threw a wrench into this plan :)

i didn't know this, i thought they can turn ON any of their loads that they want and let the breaker on the generator determine how much power they can use.

I guess we need to pick certain loads now or plan for a large generator that will handle the calculated load.

Thanks.
Click to expand...

Look at 702.4 (B) (2) 2011. Something similar to this was brought up a while back. I think the question was would it pass inspection without the gen. in place.
IMPO if I were the inspector I would not pass it with just the ATS.
 
ceb58 said:
Look at 702.4 (B) (2) 2011. Something similar to this was brought up a while back. I think the question was would it pass inspection without the gen. in place.
IMPO if I were the inspector I would not pass it with just the ATS.
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Why not? That just says "where automatic transfer equipment is used". Until further inspections are performed to approve the future genset, the "transfer" portion of the equipment will not be used. It may change state, but it is hard to claim it is being "used".

What violation are you considering?
 
Volta said:
Why not? That just says "where automatic transfer equipment is used". Until further inspections are performed to approve the future genset, the "transfer" portion of the equipment will not be used. It may change state, but it is hard to claim it is being "used".

What violation are you considering?
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I knew I would start something:lol: If you install an ATS that takes care of the automatic part. 702.4 B 2 a & b have wording of SHALL be capable and SHALL have a capacity. If the generator is not there how do you prove that it will comply? Look at 702.1 "permanently install in their entirety, including prime movers".
Allowing the install with out the gen. in place would be an open invitation for circumventing the code. If the inspections were done and passed with say a 200 amp rated switch in place with out a gen. installed there is nothing to prevent an undersized unit to be installed later by the homeowner or some handy man.
 
ceb58 said:
I knew I would start something:lol: If you install an ATS that takes care of the automatic part. 702.4 B 2 a & b have wording of SHALL be capable and SHALL have a capacity. If the generator is not there how do you prove that it will comply? Look at 702.1 "permanently install in their entirety, including prime movers".
Allowing the install with out the gen. in place would be an open invitation for circumventing the code. If the inspections were done and passed with say a 200 amp rated switch in place with out a gen. installed there is nothing to prevent an undersized unit to be installed later by the homeowner or some handy man.
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Sorry Curtiss, I ain't buying it. Future compliance is the generator install inspection. I still say its legal, even if maybe a bad idea since generator isn't speced yet. OP did not state this in the beginning.
 
Many utilities and retailers have automatic transferswitches installed, but do not have permanent generators, they rent or have portables in storage to be dispatched to the site during hurricanes and other known natural disasters for back up if needed. Saves having to place a generator at every site. I did one for a large telephone switching station that backed up the two one meg generators in case both of those failed, or were under maintaince. The AHJ may balk at it because someone may install a generator later without permiting the install, but legally, until they do it, there's nothing he can do about it, unless it is written into the local code.
 
Volta said:
Yup. Future work is not part of this job.
Click to expand...

We are going to agree to disagree. The inspector may or may not pass it. I am just saying the wording in 702.1 "installed in there entirety,including the prime movers" to me says the complete system must be in place if an ATS were installed so that it could be verified that it meets 702.4 (B)(2) 2011

702.1 Scope.
​
​
The provisions of this article apply to the​
​

installation and operation of optional standby systems.
The systems covered by this article consist of those

that are permanently installed in their entirety, including
prime movers, and those that are arranged for a connection
to a premises wiring system from a portable alternate​

power supply​
Click to expand...


 
ceb58 said:
We are going to agree to disagree. The inspector may or may not pass it. I am just saying the wording in 702.1 "installed in there entirety,including the prime movers" to me says the complete system must be in place if an ATS were installed so that it could be verified that it meets 702.4 (B)(2) 2011
Click to expand...

I'll admit that I'm pushing it a little but- that is preceded by 'The systems covered by this article consist of those that are permanently...". So, until the genset exists, 702 doesn't apply. :angel:
 
Volta said:
I'll admit that I'm pushing it a little but- that is preceded by 'The systems covered by this article consist of those that are permanently...". So, until the genset exists, 702 doesn't apply. :angel:
Click to expand...

Thats the way I look at it
 
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