Stand by generator sizing

[nizak]

After spending the last few days speaking with generator sales people and a handful of local contractors I am convinced that a fair amount of residential stand by whole house generator units are actually improperly installed.I'm finding that contractors are selling 20KW units with service rated 200A transfer switches( seem to be priced quite well when packaged together) and putting them in with the majority of them having only load shed capability for AC.When I ask about high amperage draw appliances(dryers, ranges, ovens etc) I am being told that "we just tell the customer they won't be able to run those items and to use commom sense".One Co. told me that they know a good majority of the AHJ's and they never look any further than if the unit starts up. One guy even went so far as to say if you actually size it to the full load, you'll never get the job because the unit is going to be too expensive. Does anyone else work in area where there seems to be no real enforcement of NEC 702? I realize that common sense goes a long way in many of these situations and many probably never have a issue but who takes the heat when you get the customers calling saying their units are going into overload and they can't operate their "whole house" after they spent $6K on the set up?

 

[eHunter]

After spending the last few days speaking with generator sales people and a handful of local contractors I am convinced that a fair amount of residential stand by whole house generator units are actually improperly installed.I'm finding that contractors are selling 20KW units with service rated 200A transfer switches( seem to be priced quite well when packaged together) and putting them in with the majority of them having only load shed capability for AC.When I ask about high amperage draw appliances(dryers, ranges, ovens etc) I am being told that "we just tell the customer they won't be able to run those items and to use commom sense".One Co. told me that they know a good majority of the AHJ's and they never look any further than if the unit starts up. One guy even went so far as to say if you actually size it to the full load, you'll never get the job because the unit is going to be too expensive. Does anyone else work in area where there seems to be no real enforcement of NEC 702? I realize that common sense goes a long way in many of these situations and many probably never have a issue but who takes the heat when you get the customers calling saying their units are going into overload and they can't operate their "whole house" after they spent $6K on the set up?

You have only discovered the tip of this iceberg.
I see and hear several horror stories about dissatisfied residential generator installations weekly.
They range from "it won't stay running", to "my brand new generator is damaged, does not work and the warranty does not cover the problems".
Many inspectors do not give enough attention to 702 installations and many are not knowledgeable about generators, generator installations, generator neutral-ground bonding and or generator loading.
Many AHJ inspectors I am familiar with don't even inspect or ask about the ATS or generator.

With the recent increase in residential generator installs, I suspect that the AHJ's will begin to police genset installs more thoroughly in the near future.

 

[nizak]

I feel that with something as important as a back up system, municipalities would require at the time the permit is issued a worksheet spelling out the intended install. This could easily include load calculation, generator size, and switching type. Why is it that you can be charged a re inspection fee at the rough in for missing a nail plate,or having one too many nm cables through a fire stopped hole but you can install a $5K-10K system and it doesn't even have to work properly?

 

[eHunter]

I feel that with something as important as a back up system, municipalities would require at the time the permit is issued a worksheet spelling out the intended install. This could easily include load calculation, generator size, and switching type. Why is it that you can be charged a re inspection fee at the rough in for missing a nail plate,or having one too many nm cables through a fire stopped hole but you can install a $5K-10K system and it doesn't even have to work properly?

It seems to be the way it is done.
I agree 100%, the RFQ should be solicited with a full set of specifics.

Welcome to government work.
Be happy it is not a fed job, I have waited in excess of 270 days after the job was satisfactorily completed to get paid.