Min/Max rating on HVAC unit

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mdshunk said:
That would be a neat bar trick, or maybe it would win you that round in a game of Trivial Pursuit. Otherwise, equipment has the necessary information on it already.
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Marc, considering most guys think its a violation to install a larger breaker than wire size, I think they should know why its sized the way it is...
 
Ok.....here is why I find this interesting...

I got a call from an electrician who attended a seminar of mine some time ago and he called me today and was upset.

He is in Arlington,VA and he had an inspector who failed him today...

1.) He had a nameplate that said Minimum Ampacity - 26A
2.) He had the same nameplate say Maximum OCPD/Fuse - 40A

He ran 10 AWG for the conductors and put it on a 40A breaker.....the inspector demanded that he run a conductor that could handle atleast 40A and would not accept his 10 AWG to the breaker......

He had to make a special trip to install an 8 AWG to please the inspector....it was a waste of 2 hours of his time....so if he had shown the inspector the sections that apply he may have had a chance to educate the inspector....without knowing marc no one gets educated...I like to learn everyday.....not take nameplates for granted.
 
radiopet said:
so if he had shown the inspector the sections that apply he may have had a chance to educate the inspector....without knowing marc no one gets educated...I like to learn everyday.....not take nameplates for granted.
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The inspector was ignorant of a simple code rule...nothing more, nothing less.

If the electrician knew the rules why didn't he challenge the inspector? Changing from #10 to #8 is no small task.
 
stickboy1375 said:
Marc, considering most guys think its a violation to install a larger breaker than wire size, I think they should know why its sized the way it is...
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You've polled most guys? Maybe most home inspectors, but certainly not most electricians. I'll meet you halfway and say "many installers".
 
peter d said:
The inspector was ignorant of a simple code rule...nothing more, nothing less.

If the electrician knew the rules why didn't he challenge the inspector? Changing from #10 to #8 is no small task.
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It was an example peter....I can't make the guy do anything. he simply called me to make sure he had not lost his mind and that installing to the nameplate was correct. look at my posts over in "inspector rule"..I am not downing the inspector ( I am one )..just using it as an example of a good case to know how to be able to do it...and if someone uses it to teach someone how so be it.....I told them to have the inspector call me I would gladly explain it...i dont mind...
 
mdshunk said:
You've polled most guys? Maybe most home inspectors, but certainly not most electricians. I'll meet you halfway and say "many installers".
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Love the Home Inspector reference marc.......i am guessing you feel most home inspectors dont understand how to read nameplates or value the ability to actually calculate the values?

OH BTW.....other than the extremely educated electricians who come onto this site......consider I do quite a few seminars and talk about many topics and you would be surprised what is not known...that you may think is known. ( thanks to grandfathering atleast in my state )
 
radiopet said:
....i am guessing you feel most home inspectors dont understand how to read nameplates or value the ability to actually calculate the values?
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Haven't said that at all. If you feel the need to put words in my mouth to stir the pot, feel free. I'm a big boy. Lord knows you're certainly a BIG boy. :grin:
 
nope.....was just asking..thats all....As for being a Big Boy...yep and one that backs it up also...;)

FYI....I dont stir any pots....heck I dont even do anything for that industry anymore, You answer more questions for them than I do anymore.
 
radiopet said:
...As for being a Big Boy...yep and one that backs it up also...;)
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I just remember a picture of you on a motorcycle, and I think you were holding it down to the mat for the three-count with your backside. I'm not sure. Either that, or you were riding it.
 
mdshunk said:
I just remember a picture of you on a motorcycle, and I think you were holding it down to the mat for the three-count with your backside. I'm not sure. Either that, or you were riding it.
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That was a chopper and it already rides low. Dang man......whats with the fat references....is this an electrical site or weight watchers...I am 5' 10" and weight 238 pounds......not like I am 500 pounds and sloppin up a big mac every hour.....geessshhhh
 
radiopet said:
....
but if the electrician had to do it in the field....and no nameplate they should know how to do it without a nameplate....agreed?
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If you don't have some type of nameplate you can't do it. You have to know the FLA of the compressor and the the fan motor to make the calculations. I have never seen a nameplate that gave me the information that I would need to make my own calculations that did not also have the minimum circuit ampacity and the maximum OCPD shown.
 
Your pic example sort of confuses me......because 440.32 only applies if the compressor motor is a wye-start, delta-run winding config, correct? (430.22(C)). If it's not....can you still apply the 58%x1.25 demand to the motor current?
 
don_resqcapt19 said:
If you don't have some type of nameplate you can't do it. You have to know the FLA of the compressor and the the fan motor to make the calculations. I have never seen a nameplate that gave me the information that I would need to make my own calculations that did not also have the minimum circuit ampacity and the maximum OCPD shown.
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ok .....why even have the information provided in 440.22 and 440.32 if its pointless info. What if the manual gave info BUT no nameplate..aahhhh...guess it violates 440.4 at that point anyway.....just figured someone would like to know how they figure it.....chalk it up to indeed bar tricks.....I still like knowing how to do it but.....oh well.....Points taken....i will keep it for the classroom.
 
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