code queastion of the day!!!

[copper chopper]

lets take 3 vavs 480 volt 3 phase total amperage of 21.7 amps and hook them all up on 1 30 amp circuit, however on the sticker on each vav it states max circuit protection 15 amps and each vav has a 3 pole fuse block in it with 15 amp fuses protecting the heating coil only. IS THIS LEGAL OR NOT please provide code articles to back up your answer...

 

[Cow]

Not legal. I'm not going to look up the article but I'll give you a hint. It's the one stating you have to follow manufacturers instructions.

 

[augie47]

In addition to cow's answer I would think you might check out 240.40 as you did not mention a disconnecting means.

 

[squaredan]

Not legal. I'm not going to look up the article but I'll give you a hint. It's the one stating you have to follow manufacturers instructions.

Art. 110.3B .... Are these heating packages for an Air handler?

 

[GoldDigger]

Art. 110.3B .... Are these heating packages for an Air handler?

Variable Air Volume box (vav) implies air handler. A VAV with reheat (heating elements) is a way of increasing the air temperature of that zone when the common air mix is too cool for that zone and just cutting the cool air flow to reach the designed room temp would result in too little ventilation. A good system design will minimize the need to actually use the heaters.

 

[squaredan]

yep, Thanks GoldDigger

Dan

 

[hurk27]

Are we sure that the sticker is not just pointing out that the fuses in each VAV should not be sized over 15 amps? it would depend upon how its worded, Being that there is end of run OCPD's the conductors to these VAV's are now feeders, and I don't know of any code that would prevent a larger feeder circuit from feeding these?