Is this legal?

[Jerseydaze]

I'm looking at home depot and they have a manual transfer panel that is 200 amp street and 40 amp generator .The add even states that it allows the home owner to select and breaker to be controlled by the generator. I can just see a home owner calling cause the generator is tripping the Main. Seems like a bad design.

 

[iwire]

It is 100% OK as long as it's a manual transfer switch.

Up until recently it was also OK with a automatic transfer switch, now the manufacturers have gotten the code changed so a Generator with ATS must be sized to carry all the load.

Personally I think that the change was a slap in the face to consumers.

 

[Rich R]

Yes as long as it is a manual switch

 

[ceb58]

Personally I think that the change was a slap in the face to consumers.

I understand what you are saying but, mfg. reasoning aside, I have done installs for older people that them trying to remember what to do, how to do it and the fact of them safely getting to a manual switch to operate it would not be in their best interest.

 

[iwire]

I understand what you are saying but, mfg. reasoning aside, I have done installs for older people that them trying to remember what to do, how to do it and the fact of them safely getting to a manual switch to operate it would not be in their best interest.

So is that not a choice that should be left to the consumer?

What is the safety issue?

These are optional systems, not required.

 

[brantmacga]

It is 100% OK as long as it's a manual transfer switch.

Up until recently it was also OK with a automatic transfer switch, now the manufacturers have gotten the code changed so a Generator with ATS must be sized to carry all the load.

Personally I think that the change was a slap in the face to consumers.

that change really worried me, as I was afraid of losing sales based on it.

but as of this time, none of the jurisdictions i've worked in are enforcing it; which I have no problem with as I do not see it as a safety issue.

 

[infinity]

So is that not a choice that should be left to the consumer?

What is the safety issue?

These are optional systems, not required.

I agree with Bob here. The nature of these systems is convenience and now the consumer is taking it on the chin because someone thought that this is a good idea.

 

[ActionDave]

Here we have a lot of second home owners. Hard to sell them on the idea that they need a generator capable of powering the whole house when they just want to make sure the food in the freezer stays frozen while they are out for a few weeks.

Stupid rule and it has affected our business.

 

[LarryFine]

If you can have the offending loads drop out during genny operation, you're okay. It's easy to do on, for example, an HVAC system by interrupting the 24v control voltage.

 

[Pierre C Belarge]

I agree with Bob here. The nature of these systems is convenience and now the consumer is taking it on the chin because someone thought that this is a good idea.

AKA, manufacturers getting their hand deep into the crevices of the NEC.

 

[wireguru]

While I dont think it was a good idea either, but I sort of see the reason for the code change.

Question:
does the generator have to be sized to the entire house, or sized to whatever is on the load side of the ATS? For example, can I have a 200a service with two 100a subpanels. One is behind an ATS and the other is not. Can the generator be sized for the entire load on the ATS panel?

 

[ceb58]

While I dont think it was a good idea either, but I sort of see the reason for the code change.

Question:
does the generator have to be sized to the entire house, or sized to whatever is on the load side of the ATS? For example, can I have a 200a service with two 100a subpanels. One is behind an ATS and the other is not. Can the generator be sized for the entire load on the ATS panel?

Yes. 702.5 2 a b You could have it supplying one panel in your example or it could be sized for selected loads in the 200amp as long as there was load shedding devices.

 

[hurk27]

While I dont think it was a good idea either, but I sort of see the reason for the code change.

Question:
does the generator have to be sized to the entire house, or sized to whatever is on the load side of the ATS? For example, can I have a 200a service with two 100a subpanels. One is behind an ATS and the other is not. Can the generator be sized for the entire load on the ATS panel?

Yes, as long as it is sized for the caculated load on the panel the ATS feeds.


I some what agree with the code change as having an ATS switching into a load over the generators rating will only cause more problems with the generator tripping back out, or causing damage to it, if the OCPD doesn't trip (which I have had happened more then once)

But there are some loads that should not have been required to be used in this caculation.
any load that does not automaticly come back on when the generator comes online, such as electronicly controled ovens, micro-waves.
the requirment to use the full rating of a recessed light when the owners use CFL's and are instructed to such.

to me any load that does not return to the "on" state when power is restored, is a self load shedding load, and should not be required to be included in the caculation.

As far as selling whole house system's, we install more of these then any other type, our punch line is this, after they pay for the labor of us sorting out which loads they want to place upon the generator, installing a smaller ATS, or using one of those ATS/panel combos, they can afford having the whole house powered for just a little more. But around here were talking most all homes comming in around 65 to 75 amps caculated load, with all gas heat and appliances, we do a 20kw genset that comes with a 200 amp service rated transfer switch, locate the generator next to the service, our gas meters are also next to the service, job is about 4 hours labor and were done, all for about $8200-$9500 depending upon distances. our POCO will upgrade the gas meter to a 350k BTU for free, so thats not a cost. generators come with the transfer switch, and we pay around $4200 for them.
So it's been a money maker for us, just did 2 this weekend.

 

[LJSMITH1]

AKA, manufacturers getting their hand deep into the crevices of the NEC.

I am sure *some* are...not all...