A lot of technicians in the commercial market have to install and adjust belts, and these fan belts are getting less and less as blower motors and fan motors. Get it to be more and more direct drive. But you still see a lot of them out there and knowing how to install them and adjust them is going to be really key to your success now. The first thing i want to do is dispel some myths.

A lot of people will say things like you want to tension a belt until it has half inch of deflection or one inch of deflection. But that really can't be the case, because obviously it would depend on how hard you squeezed, how strong your hands were and how long the belt was, what type of belt it was for that rule to make sense. So a lot of technicians have come up with you know, sort of calibrated fingers as far as what is and is not the correct tension for a belt. So there are no simple rules of thumb, but you do have to know a little bit about belts before we can go any further.

The first is, i suggest that you get the browning app browning does a great job of describing how all of this works. They also have some tools that will help you tension, so reference their information as much as possible. If you have an adjustable drive, pulley a lot of people, call it a shiv or you know it's kind of spelled like sheave. If you have one of those adjustable drive, pulleys do not adjust the adjustable drive pulley.

In order to set the belt tension, you set the belt tension by adjusting generally, it's going to be the foot mount of the motor in order to tension and untension make sure before you replace a belt or if you have a belt, that's squealing before you adjust It that you've actually inspected the drive and the driven pulley to ensure that the pulley itself is in proper condition. In many cases, the pulleys will actually get worn out. So they'll have a really smooth surface or they'll be an incorrect shape. You can get a pulley gauge to actually see if it is worn or not, but many times you can just do that just by paying attention to it kind of rolling around looking for ridges or damage to the pulley.

If you do have a damaged, pulley you're going to want to replace the pulleys and you're going to want to do that sooner than later before they start eating up a bunch of belts or before you get squealing or things like that here on this image, you Can see some of the different components to the adjustable drive pulley, the one that we call the the shiv and with the adjustable drive pulley adjusting the two halves of the pulley closer together results in more airflow and adjusting it further apart results in less that's only Something a test and balance organization or somebody who's doing a commissioning with set, or maybe a retro commissioning, because you have to measure airflow in order to do that properly in the field. We are not going to be adjusting that adjustable drive pulley, but if we are going to replace a belt, the right thing to do is to adjust it inward adjust the motor base inward. So that way the belt gets loose or put the new belt on and then re-tension it appropriately and the best way to do that is with a tensioning tool. Now i know a lot of you won't be using a tensioning tool, but again i suggest you use the browning toolbox.

Technician app and browning uses this line in the app which i think is brilliant. It says ideal tension is the lowest tension at which the belt will not slip at peak conditions, meaning when that motor is starting. That's generally, when it's going to have that kind of peak load on it, you don't want that motor to slip or squeal. If you've ever heard a belt, that's squealing! Whenever the motor starts, you can know how annoying that can be, and that creates further wear to the pulleys.

But you don't want it any tighter than that. A lot of technicians will incorrectly state that you're supposed to set belt tension based on blower amperage and that's a terrible idea. The belt tension is placing some forces onto that blower motor shaft, but potentially and as you as you know, with many other motors that motor could run. You know decent level below its full load, amperage based on how the adjustable drive pulley is set and if you are tensioning it so tight that you're actually binding down those bearings and making the motor draw a higher amperage you're doing damage to the motor and motor Bearings, the pulleys, the belt everything else so do not over tighten the belt.

You want to get it just tight enough. So that way, there is no squealing and no slipping even on start, but no tighter than that now again, because they can start to kind of wear in pretty quickly technically you're supposed to go back and adjust within a few hours of initially running it or a Few days - and you know we know - that's probably not practical in a lot of cases unless you're in a maintenance environment where you're maybe doing facilities and you're always at the same site. So you may be a little bit tighter than that. But you don't want to stretch belts out.

You also see a lot of text, go back and keep adjusting belts and stretching them and stretching them. If a belt is stretched enough, that you need a significant adjustment, then you need to go ahead and just get a new belt and then also pay attention to that pulley and pulley condition. Now again, a proper tensioning tool allows you to apply a set amount of force and then look at a fixed amount of deflection and again, browning has some great videos on this, and they have a tool specifically made for this purpose that you can use again refer To their application, a lot of technicians again aren't even aware that this exists i suggest to attack even if you're not going to use it every single time. Do it on several occasions until you can get used to what the proper tensioning is for that particular belt.

With that particular width, because there is so much variation using a rule of thumb like half inch deflection, just makes no sense, because you don't have a fixed amount of force that you use. So that's it when you're replacing a belt. Make sure that you loosen it all up so that way, you're not stretching the belt to roll it on or roll it off, don't adjust the belt significantly. If you need significant adjustments, then just get a new belt inspect your pulleys do not adjust an adjustable drive.

Pulley in the field, unless you're doing something like a retro commissioning or a test and balance an application where you're actually measuring airflow and making sure that it fits and do not over tighten a belt. So that way, you're binding down on that motor. The old line that we set our belt tension based on blower motor current could not be more incorrect. Final thing, i'll mention is that in some cases you get slippage and that sort of thing just because of the conditions around the belt, whether it's greasy or oily.

If you have anything like that, make sure you clean it and make sure you address the source of the problem before just constantly adjusting or replacing belts so install your belts, properly tension them properly and pay close attention to police and you'll be just fine thanks for Watching our video, if you enjoyed it and got something out of it, if you wouldn't mind hitting the thumbs up button to like the video subscribe to the channel and click, the notifications bell to be notified when new videos come out, hbac school is far more than A youtube channel you can find out more by going to hvacrschool.com, which is our website and hub for all of our content, including tech tips, videos, podcasts and so much more. You can also subscribe to the podcast on any podcast app of your choosing. You can also join our facebook group if you want to weigh in on the conversation yourself thanks again for watching you.