@hvacr videos - Hey Chris - Great video! Full disclosure, I'm the Product Manager for Greenheck with this product line. First off - our mistake that the wheel came off the shaft like that. Done correctly, it takes over 2000lb of force to separate the shaft from the hub! With regard to the set screw on the bushing - that is solely there to keep the key in place and to hold the bushing on the shaft what the wheel is assembled to the bushing. If you place the bushing on the shaft first (without the wheel attached), you can easily tighten the set screw as the wheel isn't in the way. we ship it to you installed into the hub just so it doesn't get lost. After the bushing is in place - then install the wheel with the mating hub and tighten the two cap screws that compress the tapered bushing and lock everything in place. with regard to the hub appearing to shift on the wheel - you and the others that commented are correct, that is just the aerodynamics causing the grease pattern to look like that. The rivets used completely fill the hole and it couldn't shift. The major benefit to this hub design is that we use this for direct drive fans as well, where a motor change requires the fan wheel to be removed from the motor shaft. The bushing interface almost guarantees the wheel can be removed from the shaft easily if a motor fails. Keep up the good work!
@David Mayer I appreciate the response and I understand where this would help with the direct drive motors as I made another video calling out your competitor on their silly direct drive fan design..... your design in this instance would have helped when I worked on the competitors fan. In the case of this video with your fan I understand what your saying as far as installing the bushing first but to be fair that requires several steps to ensure the wheel is installed correctly basically we would install the wheel than test fit , make possible adjustments and than re install for the permanent fit. Now that I know it makes more sense and for the next time it should go easier..... again I hope you don't take offense as I was just frustrated and venting some concerns!
@@HVACRVIDEOS no offense taken. Understand frustrating moments like this especially when you have a customer expecting to be up and running ASAP. You’re right you need to make sure the wheel is in the right position. In the case of our belt drive fans the bushing will be flush with the end of the shaft.
Suppliers and manufacturers should take note of this comment and feedback, RU-vid has a big audience like Chris does when it comes to HVACR. Manufacturers should be watching these videos and improve on serviceability and get feedback from people who are really in the field.
Interesting.. Well addressed to both of all y'all's.. If the dish is deep enough and the set screw angled approprately on the radius, you could have a hole in the fan ( see FOUR) that allows you to slide a right angled allen wrench in from the other side of the fan and engage the set screw.. if you get what I'm saying
@ 09:56 that shifting could just be the dead zone/low pressure area when the fan is on, I've seen this type of look in high velocity fans, some areas are completely void of dust while others are caked.
mechanic here, 1/4 drive hex bit, 3 foot wobbly extension. You would get a straight shot at it. Given the footery stuff you do perhaps a modest 1/4 drive set would be good to keep about.
Depending on dish angle, a ball end Allen bit might get enough angle on it. I would also use a wobble tip extending if possible rather than a swivel, so you get less slop.
We had one do the same thing at work, set screw backed itself off and dropped the blower wheel right off the shaft. Except in my case nobody bothered to say anything about the exhaust fan not working, we found out the next morning when smoke wasn't being pulled out from over the grills and I went up to check it out....found the same issue you did.
@@OcRefrig i hate this way of thinking, I curse like a sailor and tell jokes that would gag a maggot, But calling somebody pc or snowflake shows how sensitive you are
I work with a lot of tapered bushings in 5-20 hp applications. A key is completely meaningless in a properly installed tapered bushing. That being said, Since you know the location on the shaft, install the bushing first and tighten the set screw. Then place the driven part (fan hub) over the bushing, and tighten to manufacturers specs in an alternating pattern. that will close the bushing, causing the set screw to tighten further into the key. In your case the key falling out did not cause the bushing failure. Instead, the bushing coming loose allowed the key to fall out.
The part of the hub with the set screw goes on the shaft first and tighten the set screw where the hub needs to be on the shaft with key. Then put on wheel, then the other half of the hub and tighten hub together. So set screw is only to hold on the first half of the hub and key in place to shaft, to maintain the wheel spacing. So install the wheel and hub with out loosing your spacing.
Yep, like an old British bike. Sequence is everything and at first look you shake your head and go.. why, limey, WHY??? but then you step back and see the sense of it and go.. aaaahhh ooooohhkay.. yeah. that's fine.. hah hah!
It sounds logical enough, except that if you've worked with motors (tool and otherwise), the grub screw is generally the _first_ thing to come loose when you pull something, and the last thing to be tightened when you reinstall. It's like suddenly switching the green and red on stop lights, then complaining that people keep stopping on the red. It might be a great idea, but if you don't tell people you're doing it.....
Back in December I had the same thing happen. I had been out in the snow all day and finished my last call and told I could go home. On the way home..., well you know the rest. On call techs both busy and I was the closest technician. It was snowing all day, and now there one more roof top piece of equipment to work on. It's a Friday night, and all I want is a hot shower. Same exact unit. Same exact problem on a brand new exhaust fan. The only difference being, that little demon set screw is gone, and the fan was out of balance which was my reasoning for the set screw to come loose. So I reset the fan blower and restarted the unit. That when I noticed the vibrations. I took pictures and videos and sent my notes to Greenheck. After the holidays, they sent out a new blower fan. Now it's the deep freeze, oh joy. It's amazing how motivated you can be when you are trying to avoid becoming a tech-sicle. I never did receive a reply to my query about the blower fan having issues with the set screw, but I think your video has answered my questions quite well. Thank You for the video.
Looking at the Carrier units on that bank, once the heat kicks on, they'll have a nice burned hole in their wall. And yeah that duct detector doesn't look kosher at all. If I were the inspector I'd fail it on the spot for the duct detector and not following manufacturer's instructions for clearance. And what the flip is with those curbs? Who puts a curb like that on a brand new building?
I do install work, i can’t tell you how many times designs don’t even work on print. We joke about how jobs would look if we just did what the prints/engineer said to do all the time. I guess they actual did just that.
I’ve came into the same situation with EF set screws. My fix for that was buy a socket set of allan wrenches and use a swivel with a long extension. Works great and no hassle.
That new bank being built will most likely be a new customer in a few months. Looks like a good money-maker for you, since it seems like half of it needs to be completely re-done.
Oh, an update on my store's Traulsen side-by-side reach-in... We're STILL waiting for it to be fixed. It worked properly for almost two whole days (with a new compressor, no idea if they bolted it down this time) before it started maintaining 20-30 above (when set to -4). The other day it was sitting at 41, then it went into defrost mode. I jokingly turned to one of the new girls (with "real," a.k.a. non-chain-restaurant experience) and said, "Why is it going into defrost mode when it never gets below the freezing point?" Compressor replaced: September 29, 2020. Fails to maintain set temp: October 01, 2020. Tech called, a "part" is on order. Still waiting for part: October 16, 2020. A cursory Google search for "HVAC supply house ct" brings up 12 supply houses within an hour's drive, give or take depending on traffic. There's another dozen or so in Rhode Island, also within that hour-or-so's drive. Heck, there's probably parts on Amazon, because everything is on Amazon. What on earth could this Traulsen need that can't be sourced reasonably easily? Is the part being shipped by Pony Express? Yesterday, surprisingly, without any intervention or service, the Traulsen decided it wanted to work, and it held -2 to +1 all day, aside from a brief rise to +4 when we loaded some product into it. We watched the temp readout like a hawk and verified with a glass-bulb thermometer often, and we didn't have a single issue. But we don't dare tell anyone that, because then the service call will get canceled, and when it craps out again we'll have to start the whole process over... Every time I come into work and someone tells me, "the guy came in and fixed [insert failed equipment here]," my immediate response is, "so, is it going to fail later today, or will it wait until tomorrow?" Sad thing is, I'm usually right, it fails again within a 24-hour period. We use some stupid one-size-fits-all approach of a general restaurant maintenance contractor. I assume we picked the lowest bid, and we're getting exactly what we paid for.
@HVACRVIDEOS I always keep a full set of torx bits in my bit holding screwdriver to tap into stripped allen screws. Once I tap it in I can tighten and loosen the set screws again. Saved my bacon more times than I like to mention. I never use swivel allen keys anymore because of it.
My guess is the disk of the fan is curved like that for structural reasons. The dish it has is a much stiffer option, than if it was flat. Unfortunately that creates a problem for technicians.
Speaking about inventory, lately we have been told to drain down the local distribution centers and send parts to Europe. Our companies parent company is out of France and are having even longer lead times then we are.
If it were me I would Drill and tap the end of the shaft and bolt an over sized washer on the end to guarantee that it never happens again. Set screws and compression hubs are not good choices for axial loading
Talking about waiting on parts I looked at a trane that tripped the breaker the compressor was grounded called train compressor was still under warranty no one in the nation had it. Had to special order it 20days before it is shipped to Nashville lol had to tell the customer they have fan and emergency heat but no ac until it comes in glad they understood
I think all of your assumptions are correct. And some people think everything is an emergency. Where are you supposed to get parts in the middle of the night.
Browning makes H bushings with the set screw in the flange. They just need to spec the right one. Good work Chris. The RTU needs a bond wire on the gas line and the vent for the furnace will melt the front wall coverings.
One of the few youtubers I’ve heard actually say “watch the ads to support me”. I agree that’s the easiest way to literally put money in the creator’s pocket. If a video is good I will make a point of sitting through the ads for precisely that reason. I’m surprised more people don’t say it.
That shifting stain looks like a splatter pattern. Probably from caked on grease/oil in the center that got knocked everywhere when the fan dropped and just... stopped. Hard.
Start carrying some J-B Weld with you, or a tig welder! And I can understand the customer's situation - it seems like there is a crisis and so you (re)act, only to later realize that you didn't need to rush to get it fixed. Been on both sides of that situation. Love the channel.
I work on A LOT of these greenheck fans. Quality control is questionable at best. I wouldn’t be surprised if the taper wasn’t tightened completely from the factory and I’ve had a few drop the wheel like that. I’ve even got new ones with rubbing wheels that I’ve had to reset.
That exhaust fan seems like it is designed for entire exhaust fan change out and is not supposed to be repaired only replaced! I had one with a stripped set screw and I drilled it out and used a 1/4 20 tap to thread a new hole! Then I used a 1/4 20 bolt as a set screw and used red locktight and it worked fine! Thanks for another awesome video!
Wera has Hex-Plus wrenches/drivers/bits that will still work if the screw is already striped and won't strip it in the 1st place. They have saved my butt many times when I find stripped or very stuck hex screws.
Those damn exhaust fans are a nightmare to repair. Especially when you have to take it all the way apart like that. I am completely shocked that you didn't run into problems with the wheel hitting the shroud.
Good video ! Engineers Wet Dreams = a Technicians nightmare. All Engineers should be Required to Work in the Field Of Repair for 1 Year Min BEFORE They are allowed to officially Design stuff.
I love greenheck good support and parts always got to me quickly and effective, But I had almost every manufacturer of HVAC-R equipment with defective equipment from factory, from refrigeration to RTU units
I haven't watched the full thing but intro gives me good vibes of what's to come. Also, do you ever come across a well maintained/cleaned unit? Also thank you for the timestamps :D
I LOVE you videos. I unwind after work with a big glass of milk and my dog at my feet. Didn’t know that about the ads so when an ad pops up I’ll leave the vid and refill the glass. Thanks from Canada. :)
Set screw just holds the key and bushing into place. Its best to put the bushing on first, tighten that down (5/64" if I remember for those QTs), then install the wheel. Easy peasy. No need to try and reach the set screw with wheel installed. Also note, not all qt bushings have set screws depending on the bore, in those cases it can help to beat the key's edges with a hammer a bit to deform it then it'll have an interference fit on the keyway and you can tap your bushing where you need it while still maintaining a good general hold on the shaft.
Chris: if a hub is not quite tight enough, cut a piece of aluminum pop can in a strip and make a shim out of it. Place between the split taper and the outer hub. You won’t need a long piece, short will do, or put 2 small pieces- one on each half of the split. That’ll make it super tight when you snug the screws up. Great temporary fix and will still be removable for permanent repair later. If need be, a thin coat of grease will hold them in place while you slide the hub together.
Your comment about the set screw is what I think about so many of the units you work on. Manufacturers/Engineers totally do not think about how a unit needs to be maintained or serviced.
Which kind of fans would you use? In Canada we get the same "Dome" fans and also sometimes use a "utility" fan, which is an up blast centrifugal type (of which most of them aren't designed for kitchen grease)
@@jdniedner We usually use a fan built into a square box which attaches in the middle of the ductwork, then the end of the ductwork will just have a square grille on it.
You should get some ball end hex bits/sockets, they are really useful for this kind of issue. From my experience, Bondhus stuff is really good (one small 3/32" hex key went through an entire robotics season without getting noticeable wear).
Your illusion of shifting is most likely a dust buildup pattern on the backside or eddy of the airflow being as drawing vaporized oil out of the building it sticks there then dust sticks to that kinda hardening and filling out the rough edges to make a more aerodynamic surface even if it were filler putty instead it's just natural fluid dynamics taking away sharp angles
Next door is probably a case of "you get what you pay for". Everyone is always trying to find the cheapest labor for everything and ways to reduce "costs". When someone is being paid below what they should for a job, they're going to cut corners and not really care about quality of work. "Get it done, get out.".
So much work on the exhaust fan! First, the wheel fell off the shaft, next the keyway was lost then you went to get the replacement wheel but it had a hard time, And finally, you discovered that one HVAC package unit that the blower acces panel is facing the wall! One thing turns into another!
@8:38 what about taking the sheve off and pulling the haft out of the motor mount assembly, putting the shaft on the fam and tightining the set screw and placing the shaft back on the motor mount?
QD bushing, another trick is put a slight point on the bolts so when you push the hub off it doesn't mushroom the end of the bolt and then screw up the threads when you pull the bolts back out and keep everything free of oil, you can over tighten those bushings if there's lube on the taper faces.
@@norwegiannationalist7678 It does not make sense to call something the best. Americans are just as happy with their units* as we are with SI. * As far as I know the US also completed the transition to metric, just in the every day life it is so common to use the "old" units so it is difficult to let them go.
as a guy who does auto repair watching him struggle with that set screw with miles of room was absolutely hilarious not going to lie, he could have just used regular Allen keys, or a hex socket set with a swivel and extensions and it wouldn't have even been an issue.
They have a rounded head Torx Allen head bit it's extended so that you can use in situations like that were you need to angle it in a certain degree. Check your local Snap-on or any tool distributor
something you might look into for the toolbag, since its a couple small things, is a 1/4 or 3/8 drive, 2' extension, with a ujoint on the end, and a small hex/torx bit set. id bet that would make removing set screws in small spaces like that a ton easer.
Hint for tightening/loosening those set screws, use 1/4" ratchet set allen key socket with angle coupling and extension. Drive with ratchet handle or 1/4" socket screwdriver handle. Also, to give yourself clearance, undo the shaft supports and slide it down to open the gap. BTW, really enjoy your videos and big picture philosophy.
Take the screws out of the taper hub and use them as jack screws to pull the taper hub out of the wheel. Then tighten/loosen the set screw. Hub should be flush with the end of the shaft
usually you are fighting to get the wheel off.... I would swear it shifted as well, but I have seen funny patterns form once a blower or fan has been running. Thanks for sharing !
I've had a fan drop a wheel too! I'll bet yours has a very close serial number to mine. What a pain. My fan was a sidewall fan 16' in the air. More time setting up scaffold than anything. Crossing my fingers and knocking on wood that is doesn't drop again!
Reccomend that when a commercial comes on...that they go to grab a snack or to take a bathroom break so as you benefit from the commercial being watched.
“What the heck, what the actual fudge man... dang it!” Ok Chris, I’m gonna have to ask you to tone down the language a bit. 😂😂😂😂😂😂😂😂😂🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣🤣 I’m kidding of course, but man did I ever need that laugh today. Thank you for that! 😀
I think the secret is that you loosen the thrust collar on the bottom pillow block, then the entire shaft will drop down and you have ample access to the set screw.
The grease spinning off the hub and creating that that shadow that makes it appear that the hub has shifted, I have seen that on evaporator fans( not grease but dirt and brakes dust) actually on the squirrel cages of the fan, when I worked in subways. I do have a question, do you ever use REMOVABLE medium strength Loctite ( some morons at work use the red Loctite on the set screw that holds the key in the keyway) on the set screw ? Maybe I missed it and you did.
Just drop a nice little high tensile bolt down the keyway, or a self tapping screw, or some brazing - hot if you wanna be fancy. LoL - I've seen all sorts of junk used to just whack it all together and "git 'er goin' again". Props for doing the job properly, man!
it's usually not the engineers that screw the tech. It's the bean counters and the guys in charge of integrating into the assembly process. At least in the automotive side, got some insight talking to a GM engineer at a bar.
About the dust, have you considered that the pattern is caused by the rotation creating a void behind the raised part as it goes around? like that spot alone is self cleaning.
Just a thought, would it be wise to have a portable exhaust fan and have that working while you fix the problem. Even I you charge customer hire charge for portable unit?
The only thing I'd look for if that hub shifted is if the leading edge had any grime pushed up on it. It looks reasonable enough to just be how it sticks during rotation leaving a sort of grime shadow.