Small generator

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iwire said:
The load can be determined by crystal ball or any other method that is acceptable to the AHJ.

Here is an installation I did last May under the 2008 NEC it left me, the customer and the inspector all with a warm fuzzy feeling. :smile:

I can not remember the KW of the genset but it certainly could not run everything in this large home, this main panel powers at least two sub panels, a steam generator, a pool central AC etc.

The owner is fully aware that he has to be selective when running the generator.

IMO I have not violated any NEC Article nor have I short changed this customer.
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How many OCD's are in that panelboard and how many was it designed to hold?
I can see 40+ there without the bottom visible.
Tom:confused:
 
Twoskinsoneman said:
you may have been intentionally obtuse.

Does this really come down to what is a clculation? Is a load reading a calculation? Sure. So yes a calculation has to be done and yes it can be done by other means. Other means being undefined except that it must be approved.
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You are so vague in your response, I do not understand.... ;)



How is a load reading a calculation??? Is there some kind of math being performed I am not aware of with meter readings?

A load reading and a calculation for the same house I am pretty sure will not come out to the same answer...unless it is pure luck.:cool:


I see some mentioning the homeowner. Most generator installations today are Optional Standby Systems.
So... it is up to the customer to pick whichever loads they want...even if that means changing the loads choosen from time to time. What is the big deal about this???

The generator stalls, they change the load by turning off some breakers (or calling their electrical contractor) and away they go.
But...the house may freeze, food in a store may thaw...that is a design issue that will hopefully be worked out before the next outage.
 
Pierre C Belarge said:
How is a load reading a calculation??? Is there some kind of math being performed I am not aware of with meter readings? [/quote]

Not real sure here but I think that a load reading has something to do with some law that was written by some fellow called Georg but we have added the "e" to his name.

In his law there was something about current equaling the voltage divided by the resistance or the wattage equaling the voltage times the current which is just what a meter does in its design.

Of course you already knew this but must have overlooked it when you made the statement above. Most certainly a meter reading is math done for us.

It is this stalling of the generator that is of concern to the end user and the reason for the change in the 2008 code cycle.


iwire said:
The load can be determined by crystal ball or any other method that is acceptable to the AHJ.
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No one is arguing this point but as you have said in this sentence a load is required to be determined in some fashion and the generator has to be sized to that load that the crystal ball came up with.

iwire said:
Here is an installation I did last May under the 2008 NEC it left me, the customer and the inspector all with a warm fuzzy feeling.
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 Not meaning to sound rude or hurt your feeling nor anything like this but are you saying that as long as the customer and the inspector has a “warm fuzzy feeling” then the verbiage of the code can be ignored?
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iwire said:
I still do not see it that way, there is an "OR" in there that surly means something. :smile:
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Yes, the "or" does mean something...it means you use the Article 220 calculation method "or" some other calculation method.
And taken with the CMPs statement the intent is clear.
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As far as the panel statement, it wouldn't be the first time that the code words did not match the panel intent. I agree that they intended to have this section mean what you say it means, (permit the use of a means other than calculation to find the load) but the actual code words do not support that. If you were to diagram this sentance, the clauses before and after the "or" would both be connected to the word "calculation".
 
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jwelectric said:
Not meaning to sound rude or hurt your feeling nor anything like this but are you saying that as long as the customer and the inspector has a ?warm fuzzy feeling? then the verbiage of the code can be ignored?
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No nothing to do with ignoring the code, just not all people see this rule the way you do or the way I do.
 
don_resqcapt19 said:
As far as the panel statement, it wouldn't be the first time that the code words did not match the panel intent.
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But it is also you that have told us many times that a CMP statement is as close to an official interpretation as we can normally get.

We just see it differently, I don't believe for a minute I will change Mike's mind and he is not going to change mine.
 
If there is one thing that I have learned about calculations...it is that few agree on the same answer. :grin:

As far as the load reading, what will the proper answer for that be? Morning, noon, over a period of a week, what time of year... you see, it will not make a big difference, that is why it is not spelled out as a requirement.


"...or by another approved method."
I usually state this says to me, based on my experience in the field with inspectors...anything goes.:roll:
I am not sure why this statement is still used in the NEC???
 
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