VAV box disconnect

[ron]

Electrically operated HVAC VAV (variable air volume) box. The box has a motorized damper and a small booster fan within (separate circuits). How have you folks provided disconnecting means on your projects.

 

[justin]

Re: VAV box disconnect

We put a surface mounted box with a toggle switch, RS cover and offset nipple connected to the transformer which was of course run to the VAV. This was placed on the wall directly below or adjacent to to the VAV. The controls guys would usually freeline their wire from the xfrmr.
You could have a seperate switch box and cover or 2 gang switch then flex to the fan motor itself.

[ November 14, 2005, 07:21 PM: Message edited by: justin ]

 

[mdshunk]

Re: VAV box disconnect

The modern Trane units that I'm famaliar with had disconnects factory supplied. On the older ones, we did use a handy box and snap switch bolted to the unit or a bar joist close by. The iris type dampers on the ones that I've installed operate off a transformer within the VAV enclosure, powered from the same circuit that powers the blower.

 

[ron]

Re: VAV box disconnect

Thanks folks.
It seems that the factory mounted switch is a specification item. So if it isn't specified with it (mech engineer), it needs to be installed separately by the EC (thus shown on my drawing).
I do so little office reno work that I didn't remember to ask the mech engineer to verify what his spec included.

 

[paul]

Re: VAV box disconnect

Originally posted by justin:
We put a surface mounted box with a toggle switch, RS cover and offset nipple connected to the transformer which was of course run to the VAV. This was placed on the wall directly below or adjacent to to the VAV. The controls guys would usually freeline their wire from the xfrmr.
You could have a seperate switch box and cover or 2 gang switch then flex to the fan motor itself.

Ditto