Really? It's a 3 hp motor.... kind of suprised.
so when does the belt need to be tensioned / waxed?
can you use a silicone type spray underneath it?
There is a difference between "peak duty HP" and "continuous duty HP." Companies like Ironman, Proform, Weslo (big box store brands basically) use peak duty. Those motor are half the size of the continuous duty motors and therefore must work much harder to produce that peak HP. They have to work at around the 5-6k RPM range as opposed to the 2.5-4k RPM range continuous duty. Just about all your appliances use continuous duty motors since they get used all the time, putting anything less than that in those environments will fizzle out quickly, it's the same thing with treadmills.
My Dad got a Proform from Sears years ago and we went through 3 motors in 2 years. That company also tells you to just go buy another treadmill instead of sending you the part you need, that's unless you are insistant on getting it, then they'll give you it. That's how those companies get your money, make inferior and cheap products, they break and people go back to buy it again, it's a cycle.
The belt needs to be tensioned when it either starts to slip or starts to track to the side. You basically have to pull the rollers back a little to tension it. Consult the owners manual to find out which way the rollers have to be tensioned.
As far as the wax is concerned, you'd have to call the manufacture. Not all manufactors use the same wax, if you put the wrong wax on it, then you take a chance on screwing up the wax, increasing the friction between deck and belt, thus making the motor work harder resulting in less motor life.