VAV

[dcspector]

Would a VAV (Variable Air Volume ) box fall under 422 or 440? I have had the opportunity to read several inspecton reports from other juridictions and the section numbers have been inconsistent.

 

[chris kennedy]

Re: VAV

Appliance. Utilization equipment, generally other than industrial, that is normally built in standardized sizes or types and is installed or connected as a unit to perform one or more functions such as clothes washing, air conditioning, food mixing, deep frying, and so forth.

Thats questionable.

440.1 Scope.The provisions of this article apply to electric motor-driven air-conditioning and refrigerating equipment and to the branch circuits and controllers for such equipment. It provides for the special considerations necessary for circuits supplying hermetic refrigerant motor-compressors and for any air-conditioning or refrigerating equipment that is supplied from a branch circuit that supplies a hermetic refrigerant motor-compressor.

Hmm, no compressor in a VAV.

How about 430?

 

[dcspector]

Re: VAV

Yeah Chris I was leaning more to 422.

 

[dcspector]

Re: VAV

I forgot to mention what if it contains a reheat system? Then could one use 424?

 

[chris kennedy]

Re: VAV

I have had the opportunity to read several inspecton reports from other juridictions and the section numbers have been inconsistent.

What are you questioning? Could you give a brief example of the inconsistent numbers that caught your eye?

Also, very odd that an inspector would spell 'inspection' and 'jurisdiction' wrong yet spell 'inconsistent' correctly. :lol:

 

[D a v e W]

Re: VAV

Curious what is the issue with the report :?:

Words spelt wrong, happens on this board all the time. No spell check that I have found :lol:

 

[dcspector]

Re: VAV

Also, very odd that an inspector would spell 'inspection' and 'jurisdiction' wrong yet spell 'inconsistent' correctly. :lol:

I was probably sober... :lol:

 

[dcspector]

Re: VAV

Chris and Dave,

This is regarding disconnecting means for the VAV. Usually the VAV's I deal with have the resistive heat strips/coils. Now with that said the units have the incorporated unit switch per 424.19© is what is and should be accepted. However, the EC's in my area are getting gigged in the surrounding areas for not field providing an additional disconnect. In summarry all I have seen on the other reports were anywhere from rediculous, to 422, 440..

 

[raider1]

Re: VAV

Chris and Dave,This is regarding disconnecting means for the VAV. Usually the VAV's I deal with have the resistive heat strips/coils. Now with that said the units have the incorporated unit switch per 424.19© is what is and should be accepted. However, the EC's in my area are getting gigged in the surrounding areas for not field providing an additional disconnect. In summarry all I have seen on the other reports were anywhere from rediculous, to 422, 440..

I agree with you on using Article 424 if the VAV has heat strips and 424.19© specifically allows the use of a unit switch as the required disconnecting means.

If the VAV did not have a heat strip or coil then my feeling is that 422 would apply and 422.34 would allow a unit switch to be used as the disconnecting means.

Chris

 

[dcspector]

Re: VAV

Thanks C.J./Raider

I am sorry to be so evasive in my op, but I was trying to get a bit of consensus regarding how one classified a VAV before giving more detail. In summary, I was on a job last week and was looking at redundant disconnects for the VAV's, heck there were 10 per floor and 12 floors to boot! All I mentioned was, "why did you install the additional disconnects"? and the story unfolded. I see this as a lack of code education and or misinterpretation on the inspectors part. Also, the additional material and labor costs the owner had to absorb....... :shock:

Thanks all, just wanted to share with you.