Came across your channel a few days ago now and I've almost managed to binge watched most of your repair videos, I don't work with HVACR, I don't have much of an interest in HVACR but watching your troubleshooting techniques has kept me interested the whole time, your explanation of how you come to your conclusions at the end of the videos are the icing on the cake. Keep up the good work! I am very sure this channel will be invaluable to guys doing HVACR repairs.
Thanks bud! I will be going live on RU-vid this evening 10/14/19 @ 5:PM (pacific time) to discuss my most recent uploads and answer questions from the LiveChat, RU-vid comments, Emails, and Facebook comments come check it out if you can. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-tB11ZTSHhhE.html
Well the object of the exercise when using a motor overload is to save the motor in the event of an overload ... I tend to be more conservative than you - I use 5%. Usually these motors are 115% service factor - so 5 to 10 % will shutdown the motor before motor damage - in the event of a nuance trip something needs to be diagnosed... nice video guy - I enjoy watching a craftsman ply his trade. Keep up the good work..
Reality is sizing your overload correctly because none of this matters when you come back and the manager maxed it out or made it disappear all together. 10%-20% and walk away. Most times when they trip its either going out or something stopping the motor. I'd stick with Allen-Bradley myself. And truth be told fuses are the best route. Overloads can be reset an unknown amount of times causing more damage. They usually call after the first box of fuses though 😂
Your content is second to none, I like that you gave tips on dos and don’t s for setting up the unit, amps, air balance, hinge kit, etc.. Thanks for taking the time to share, as always great video.
I will be going live on RU-vid this evening 10/14/19 @ 5:PM (pacific time) to discuss my most recent uploads and answer questions from the LiveChat, RU-vid comments, Emails, and Facebook comments come check it out if you can. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-tB11ZTSHhhE.html
Generally, I set the over current/ size the heaters to match the FLA on the motor... Then again, package handling equipment isn't as crucial compared to kitchen exhaust equipment. In your case, I understand why you would bump the settings up a bit. As the equipment ages or gets dirty, the FLA can increase and cause nuisance tripping, so I completely agree with that idea. Also, In my opinion, and I've done it, its ok to go 1 or 2 heater sizes up if necessary. If a motor is going bad or you lose a phase, the amps are going to go way up on the other phases, tripping the overload anyway. That being said, 10% above is a good number to work with.
I am retired now but I hated working on those fans. I had one account that I had to annually take the fan down to the ground and power wash all the greese out of it. And it was always in the middle of August in Texas when it was the hottest.
Nice and clean!! I just restored my phone and got my video app running so stay tuned for some video... liked this one I miss doing Some of that work so seeing it reminds me.of the big picture like you say
What's up Chris those hinge kits look super durable like they would last alot longer. I used to do hood and exhaust cleaning for a company before I started going to school for hvac. Those original hinges the exhaust fans come with are delicate and do always buckle you have to be super careful when doing cleanings on them but yeah I use to run into alot of exhaust fans with messed up hinge kits from other company's that just didn't care how they handled them when doing cleanings thanks for the heads up on those new hinge kits.
Service Factor/Service Factor Amps... close enough, I'm sure everyone got the point about it! for sure have to be careful setting overload currents if the bearing get tight/grease build when cold/overnight. it can trip the O/L's before it gets up to speed and load tames down
Hi all, please follow Chris’ advice in that you MUST read the OEM data on overload setting -it often differs between OEMs too! Most overload devices these days operate and protect according to a “class” characteristic. These classes (10A, 10, 20, 30) already have the ‘safety factor’ built into the protection relay thermal model. In that case, set the relay to the motor FLC/FLA. if you get nuisance tripping, and everything else is in order (voltage, star(wye)/delta links in motor, motor insulation and balance, contactor contact state, airflow, air balance, motor temperature, ambient temperature, bearings, balance, belts, blade angle/condition/cleanliness.............) perhaps you need to consider a different protection class to account for heavy starting and/or intermittent loading. This however, will almost certainly mean other components need updating (cables for sure!). Chris, you mention clamping for VFD motor current: this is only ever any good for a relative reading i.e. a current balance check. VFD output is basically pulsed DC (pulse width modulated) and as such, your poor ammeter gets a headache when measuring as it is designed to read (virtually) pure sinusoidal current. You’re bang on: use the VFD display for motor current!
Actually, if it's true RMS capable then the current reading will be accurate. Only the cheap meters are averaging types, which do require sinusoidal current.
Critical tip here: play with the belt tension to where on start the belt slips for about 1/4 second to 1 second (I doubt you can get a 1 second slip on such a small fan). What you don't want is running slip only start slip and just a little. What you are doing is removing tension which is a load on the bearings, speed and load damage bearings more load than speed. The idea is simple, belts and sheaves are cheap, motors are expensive, bearings are expensive. You are offering a preferred path of failure to the fan, a path that will save your customers time and money. Remember this is only the preferred path of failure not the one chosen by the fan but with some experience you will realize that you get more calls that endup being belt failure and not so many motor and fan bearing failures.
It's interesting how things vary from country to country. Here in the UK most fans are simply direct drive and usually wall mounted with the ducting. These fans do seem very complex, considering the simple job they do.
Yeah we really do have different systems over here, Id imagine its because we have more open space to build?? I will be going live on RU-vid this evening 1/13/20 @ 5:PM (pacific time) to discuss my most recent uploads come on over and check it out ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-YS0nIkCyXNE.html
Yep, check the tightness of the sheaves. Had a call today where the key fell out. Most awful sound ever. Luckily the maintenance guy was smart and shut it down PQD, that pulley would have chowdered the shaft if not...
I'm hurt that you would believe I would nit pick your work because I would expect you as a top line professional not to be associated with bad work practices because that route will bite you badly at some point in your work life and nobody wants that. Nice video as usual.
Hi thank you for your video It was very professional and knowledgeable. I do have a question Do you have by any chance a diagram that shows what goes where for electric installation We have 3 breakers 20 amp One for light One for sensor One for exhaust fan switch And nothing is working
Jason Mills- Chris has explained it’s not a diy channel and he doesn’t give full details for that reason. Best way to learn how to set them is to read up on the exhaust manuals online and amp ratings. Or like me to work for a company who works on exhausts and learn from the old timers.
Most overloads come with a trip rating 10-15% the fla. Just set the overload to the fla. This is direct from AB and Schneider not from me. I'm in automation and put them in every day so I wanted to be sure.
Good job Chris. I just installed an exhaust that was severely out of balance and found a company that balances the fan wheel but it was a little pricey. Those hinges look awesome and Omni should sponsor you because I’m ordering them because you recommended them.
The fan was delivered out of balance? or was it an old fan? Had a company come out and "balance" a fan. Vibration tip here: most end customers will think that a fan that is running rough, for any reason, is out of balance. This is both correct and wrong, nothing is perfectly in balance so everything is out of balance. Usually when a fan is running rough and out of balance it is due to dirt in the fan, or in the case of kitchen exhaust fans due to grease and dirt. Fans are usually well balanced at the factory to a standard spec. If done correctly the balance is good if done incorrectly the fan manufacturer can eat the cost of replacing the fan so they are usually well balanced. What I have found is that fans that are "imbalanced" are actually exciting a resonance in the support structure or the ducting. Balancing should take not much time, the box does the work, I would set a test weight let the box know where the weight is at and how much it weighs and then start the fan, the box measures the high spot and the heavy spot and tells me where to place the correcting weight. Once the correcting weight is in place the fan should run smooth as butter, not enough "O's" in smooth- smooth. If there is a resonance and not an imbalance then the box will keep showing a different place to attach the correcting weight and after attaching and removing as many weights as the world can produce usually the fan can't move air and may not be able to move at all which does solve the vibration issue.
Here are some tricks to use. if the ducting is vibrating and making loads of noise due to "imbalance" take a 2x4 or something similar and wedge it in the ducting to stiffen the part that is vibrating. Your hands can feel vibration very well use them to find what is vibrating the most. Remember your hands while very sensitive to vibration are not calibrated and they yield a qualitative (not bad vs wow bad) result versus a quantitative (less than 0.2in/sec^2 vs more than 0.8in/sec^2). you can use your cell phone to help quantify the vibration levels at different points. I use my hands as much as possible because they are just so handy. Then later I can use an instrument to help determine severity and batter isolate sources of vibration. Next if a motor is in resonance and you don't want to replace the motor just yet you can add weight. I have seen steel weights welded on, a quick search on Google will yield how to size the weight correctly. Small weights for small things and big weights for big things. Next is never forget that sand is soooo good as a weight that it deserves all the oooo's. use sand when possible to absorb vibration energy it adds weight and because it is a solid that flows like water it can dampen vibrations very well. Remember that when you find a vibration problem it could be a resonance issue and many times it is. When a belt is failing it will shed belt bits and dust everywhere around it. when a coupling is failing it will shed coupling bits and dust everywhere unless it is a spring type and then you just see metal everywhere and a very nasty noise coming from the coupling. So clean up after replacing the belts and couplings when they go out so you can see when they start to fail again. Fan isolators are shipped with the isolators "locked", test the isolators by kicking the fan with the sole of your boot give it a good hard shove type kick and the fan should remind you of a bobble head doll, if it doesn't then the isolators are still locked and hence will not isolate so the customer will be upset with the excessive vibrations. Isolators are tuned so they may need to be retuned during their lifetime they are a wear part and if the ioslators are exposed to water and begin to rust a lot then they won't be doing their job and they will call.
Motor overloads. If the motor typically runs at under it's nameplate then setting the overloads at 10% over nameplate is the way to go. If they are set to high they can't protect the motor. Other than that I beleive "most" motors are @ 1.15 service factor i think is the most common although I have seen 1.0, 1.20 and 1.25. If the motor draws at or near nameplate i would follow the service factor
Should the air intake fan have the same cfm as the exhaust fan. I had a hood installed and it cannot keep up with the char-broiler. The intake wind supply seems to blow the smoke out from under the hood before the exhaust can vacuum it out.
Why not use direct drive exhaust fans? We converted... No more belts... As long as you replace with identical CFM, voltage, phase and close current your good....
Nice job, I had many of those adjustable sheaves fail. Do you ever change them to non-adjustable ones? Also hoping you will address the voltage issues on your jobs that you have mentioned in some video's. Thanks much for the great video's.
I will be going live on RU-vid this evening 10/14/19 @ 5:PM (pacific time) to discuss my most recent uploads and answer questions from the LiveChat, RU-vid comments, Emails, and Facebook comments come check it out if you can. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-tB11ZTSHhhE.html
Hey buddy, i am from Toronto. Quick question, which do you prefer the fieldpiece or testo wireless probes? I am thinking of getting a set but unsure which is better. Thanks.
Not "really" knocking you but this is what happens when an HVAC guy deals with grease exhaust fans. You have the fan hinged on the wrong side. The way it is now, when the hood cleaners go to clean the fan the drain will be on the side of the fan, the water will have no where to go and just makes a big mess. Install the hinges so that when the fan is open the drain is on the bottom.
