AHU V-belt wear

[snydley]

Has anyone come across an article that discussed V-belt wear for air handling units with both variable pitch and fixed pitch motor puleys driving fixed pitch fan pulleys? I would be interested in applications both without VFD's (fan cycles on and off based on occupied/unoccupied cycles for a full voltgage starter and for the same used with a VFD for soft start). Normal maintenance instructions recommend changing drive belts annually but I have not seen any articles discussing extended belt life in excess of three years.
Your input is appreciated.

[jvrba]

Good question. I've heard the same thing with VFD's or soft starts changing your belts once a year. However I've examined my belts and change them on a as needed basis.

[maustin]

Change them as needed and check the tension monthly if you can. No need to replace anything that doesn't need it!

[pipefitter]

Whats everyones take on when blets get that shinny look to them I have notice on large fans producing 2" staic that in 3-4 months time they get a glazed look to them,VFD speed is higher from months ago,,so change them......
Hospital fans-40,000 cfm