You always do such an awesome job of diagnosing the root cause of the problem, then properly fixing it. I’ve learned so much from you Chris, and I’ll be doing things the exact same way that you do once I’m done trade school and I’m out working in the field. I wouldn’t have done anything differently in this particular situation. Keep up the great work and thank you for another awesome video!!! 👍🏻👍🏻👍🏻
Root cause analysis and lasting repairs, love to see it. Too many companies/people triage and never circle back (my experience in industrial maintenance)
Good that you replaced those incoming power wires when you replaced the disconnect (between disconnect and the contactors). They looked super cracked, seems like rainwater could have shorted 2 phases together. Thats something you should ALWAYS collect as info if fuses blow. How was the weather when the unit stopped working. Was it rainy, sunny, dry, wet, snowy, cold, warm etc. That gives a lot of information of potential causes, if the fuses blow only when its rainy and wet, you know there is water ingress into something electrical that is shorting it.
it's common for the outer clear jacket to get brittle, crack and fall off. I cannot say I've seen any that hasn't done that after 5+ years, indoor or outdoor.
The way you methodically check every failure point is fantastic. Other techs may have looked at those rubbed out wires by the indoor blower motor, fixed those, and called it job done. But the way you always look for every possibility makes me wish you were in my area 😂
With that large of temperature difference you should have seen some voltage drop across phase 1 of the disconnect. I suspect that you are not switching your SC-480 in to the lower range for AC volts. For whatever reason when you turn it on into the AC voltage/current range the auto range settings do not go as low as the meter will measure. If you press the range button to manually cycle through the ranges you an get to a lower range that will properly show voltage drop across a disconnect or contactor. I recently picked one up for use at work as a Production/Facilities maintenance tech and found that it does not have enough resolution in its auto range mode to see small AC voltage drops but works fine when you manually select the lowest range.
I very rarely ever use auto ranging on my meters. I've built up a habit of setting the range I am looking for at the moment I turn the meter on. I have a distrust for auto range function on meters from using some of the earlier generation meters that have it. I also feel the response time on auto range is way too slow for some test applications. It's best practice to just not rely on it with anything past the most basic of voltage checks.
Excellent video, Chris. Thanks for showing the lockout on the main breaker, keeping things safe is critical when working on equipment, particularly that which can seriously bite you both metaphorically and literally. Great job with the thermal imaging as well, something I'm surprised you don't use all the time as a means to see what is going on 'inside' the machine both on electrical and refrigeration circuits.
We change disconnects and a lot of the time just the internal parts do to repetitive on and off from operators locking out and checking equipment at our plant. They always seem to show a hot leg like you found on our thermal camera but rarely have obvious broken parts so I found this interesting. Always enjoy the videos and learn a lot. Thank you
One suggestion I have that comes from a household HVAC guy. If you do leave extra, working parts such as fuses behind put them in a bag and label it. He assumes that anything left around is something that didn't get cleaned up.
Here in the UK we wouldn't use connector (we call it a gland) inside equipment like that just a pvc grommet. As you know i love watching your videos because of the way things are done differently and things that are done the same. Sorry i've been missing HVAC overtime, been crazy busy so exhausted by friday night, and 2am is a little too late :)
Great Video !. You are absolutely right about using the IR camera. My day job is engineering manager in medium sized research facility. We have instituted IR surveys using an outside IR shop. Started 3 years ago. "Hot legs" on fused disconnects do pup up and look just like what you show in this video. We are now getting a cheap IR camera to add in-house survey's to our PM program. Insurance companies really like this too !
As an electrician, one thing I would never do is run three identical conductors without wrapping phase tape on them red and blue for the two phases on a 208 line. I even do this on single phase residential. if you did this before you disconnected, you would have less chance of having wrong phase rotation, and it also gives Assistance to the next person who opens that box so they know what phase each wire is that of course doesn’t mean that they were properly connected in the main disconnect, but at least you have some labeling scheme at your end otherwise love the videos and it has saved me a bunch in diagnosing my own systems.
Chris, I use a Kline NCVT-4IR volt tic with IR to do quick temperature checks on components and supply/return temperatures in the conditioned space. You're absolutely right on the disconnect, and temperature checks are the first thing I do after a blown main fuse... I just use my Kline IR volt tic instead of a several hundred dollar camera. As usual, beautifully described process, and thank you!
Thank you for adding the bonding conductor. Also as far as tightening stranded wires I tighten them than grab the conductors and wiggle them by hand to relax the strands and than tighten some more, works good.
I concur, I always wiggle stranded conductors when tightening and always get a little more turn. Plus anytime I am in a tight box for the first time I check all connections first. A few loose wires popping out on you a few times and you learn to check before digging around.
I bought the spigot/wand you use on coils and it is awesome for washing my truck! From mist to the strongest narrow beam, and the flex head, nothing better! Thanks for sharing about it a few weeks ago. Great channel.
Great procedure. Thank you for these videos. I always learn something from them. I, honestly, do not know how you do it to run the company and make videos hahaha. I barely survive with just work. One thing I have learned recently is that wires can produce electrical arc when they are cracked. I, kinda, saw that some of the main wires had some cracks in there. Not sure how deep they are into the insulation, but that could have happened. I think changing the disconnect after using the camera was the way to go. The problem went away. That means the procedure followed was right. Thank you, Chris. Always learning a lot for these videos. I am very grateful.
All that has to happen is a brown out, or momentary single phase condition from the utility. Also bad blades in the disconnect, will cause the fuses to run hot, and go bad. It is easy to diagnose with a non contact thermometer.
Great video! At 4:06 pause the image at 4:07 YES the wire does look in BAD condition! Cracked sheathing at minimum and maybe a rub through underneath the above red wire.
It's really nice to see when you're measuring live high voltage circuits, you do it with one hand, it's a very safe practice. Probably it would be a good idea to mention it in some videos, if you haven't done it already.
If manufacturers would bother using acutal motor (magnetic) starters with phase, overload, OV and UV protection instead of just open contactors, their stuff would maybe last a little longer. But nobody in this bracket of the trade wants that apparently.
a little observation ,when you place spare fuses ,indicate on the unit where they are,specially when there is no room inside the disconnects ,it helps a lot when your employee or yourself service the units
At 13:23 in the video the wire strands sticking out the bottom of the lug at the top of the disconnect for leg 1, look like they have a green tinge to them like they've got wet at some point, whereas leg 2 is dull copper. I'm wondering if this was the original problem and it had dried out by the time the tech got there.
Re: fuses going bad, they actually can do... cartridge fuses not so much but any fuses that are run close to their capacity will oxidize the fuse element and eventually blow. Probably a good thing the US code has the 80% requirement
Did you try reterminating that first phase? both before and after the fuse? Looks like it was loose on one end and caused it to draw more current bc of that. But yeah .. brand new box would fix it all too, especially if it was like this for awhile and drawing more and causing that one leg to overheat vs others.
may you make a video explaining how to wire RTU's using the electrical code and ampacity tables. im alwasy curious about the wire and breaker sizes in your videos for these units. And why they chose 45 amp fuses and alot of electrical questions. i know most of the info is on the nameplate but a video breaking it down explaining how you would wire, would be amazing!!!!! id pay for this type of knowledge too cause there isnt much on youtube
I think I would possibly use Crimp Ferrell's on the stranded cable. I have found you get a better connection because the strands are all clamped under the screw
If your company does the service full stop you gotta ask your employees who bypassed the economizer. Removing the wiring for the economizer was the wrong choice in my opinion, they aren't always great in every climate but the control of minimum damper position is key in many buildings to maintaining proper air balance. You've said before that the power is dirty and when you showed y1 + y2 jumped I knew a lazy or incompetent tech did what they thought was right by getting both stages on but they made a unit run nearly double the inrush current in a bad power distribution network when calling for cooling even with low load (y1 / one stage). Another thing to look at is the breaker because that unit had to have run hot and the line with the voltage drop might be losing power from a compromised breaker.
I've had fuses stickered as 30A before that one of the three blew on the control side, replaced all three couldn't find an issue, tried to pop the old fuses with a high end bench powersupply, one of the remaining 30's blew at 22 and the other at 21. Quality control, its not like it used to be.
Your double and triple loop wire ties to isolate rubouts is obviously cheaper but I have a penchant for using loom. Found a bulk variety pack of rolls of various sizes a couple years ago from an electronics wholesaler going out of business and still have a bunch!
I have a Hikmicro B01 and it is a fantastic camera for the price. It connects to my phone wirelessly so I can download images immediately to send to office or customer if needed
I am asking because in the video the screws in the disconnect box are torque in foot pounds. Is it really foot pounds or inch pound. Thank you for all the great videos . I always watch to the end for you. Don’t want a 10 out of 10 for you..
If fuses don't just go bad and you did a lot of preventative work to make sure they don't blow, why leave extra ones? What would your expectation be for them to ever blow again?
Our bosses NEPHEW(he had no business being hired),was following me to an alarm on an electric fire pump. I found a short to ground on one leg.I told him to not touch anything,as I left the electric room,I heard a bang and the lights dimmed.He tried to change the blown 400 amp fuse,with his bare hands.When I walked back in,he was just shaking his arms up and down. I then asked him why, and his reply was,I thought maybe the fuse just went bad! Idiot,lucky to be alive!
A plugged condenser coil causes fan motor current to go up. And the higher head pressure causes increased load and higher current at Compressors. (I am an Instructor for Hvac local Apprenticeship program).
Final comment, i tend to shut down the supply and use my fingers to find warm connections.... not owning a thermal image camera. But yes, one leg warm on a 3ph with no neutral is not a good sign, as you say on 2 legs is fine (sometimes)
@@HVACRVIDEOS Got the scars from where i locked onto 240v and only got saved by falling off the steps... i always verify, using a proving unit, approved tester, etc etc
@@HVACRVIDEOS trust me..I do. Verified voltage tester (either a test lamp or a solenoid voltage indicator, aka wiggy ) . Proved working with a known supply before and after the test. 415v doesn't take prisoners
You know how you take apart compressors to see what went wrong as an electrician i wouldve loved to see that disconnect get taken apart and see why that was heating up that was weird you tightened everything and checked the knifes and it still heated up what other connections are in there?!
Re: too much current on leg 1. Seems like all of your single phase motors were using leg #1 - would balance out more if the single phase motors mix it up a bit … motor 1 could be 1-2, motor 2 could be 2-3, and a third motor could be 1-3
The temperature difference would it infrared it's a very good tool it's save you time and headache The maintenance on the service was done excellent except I noticed the evaporator coil was very dirty also if the building let's say the restaurant is not balance load so also you need to check the total load balance from the main box that operate the whole entire restaurant see if the load is balanced most of the time you have in balance in the building we try to balance the load we always tell them get the election the balance the load you will save a lot of headache
I have a class RK5 60A Fusetron fuse that just went bad in a disconnect for an outdoor unit. Do you want the fuse? The circuit is protected by a 30A circuit breaker inside the house which did not trip. There’s nothing visibly wrong with the fuse; the caps are solidly attached. The other fuse is fine. They look like a perfectly matched set. The meter shows 0Ω for one and OL for the other.
if this usually happens, i always would check the disconnect. Normally when i trouble shoot blewn fuses and could't not fing short circuits, i would check the disconnect switch before i start changing the wires. I don't like that junction in the pipe from the roof. when i pull cables, i always pull a full lenght from the panel to the disconnect switch. More junctions mean more hotspots for failures.
@@HVACRVIDEOS yeah. thanks. i had done a lot of electrical trouble shooting. and i always saved a lot of time, by looking at the components that are most likely to fail, according to my experience with this kind of equipment. i also had troubleshooted electrical control wirering at refrigerator trailers and containers. And since the high pressure control was bypassed, i always looked at these. that saved a lot of time for me.
2:05 Was that the control board making those strange audible tones? Lots of odd sounds coming from it if it is. Have high pitched whistles and stuff in the audio. It must be bad even when the equipment is crying out in pain lol.
I'm wondering about the support for that box. You mounted it to the unit without any flexible connection. i thought that was frowned upon as there's nothing to absorb any vibration or movement. I thought that was why they ran flex cable from the roof to the unit was to handle any movement.
Nothing wrong with having extra, plus if one of the lugs form the Polaris connectors comes loose and burns the wire I more than likely will have extra wire to be able to cut it back and fix it
I dislike the possibility of a connection coming loose. It’s better to make secure connections that can’t come loose. An ounce of prevention is better than a pound of cure.
disconnect was not fine-it looked like that wire/lug was at 259°. that’s -way- over the 90°C it’s rated for. (and you could compare IR image of the replacement for confirmation).
Fuses CAN and DO go bad‼️Over the years the fuse element becomes fatigued due to deterioration, and heat stress from the current flow. I’ve also seen circuit breakers fail for the same reason❗️ Ambient temperatures along with high humidity, also play a part in shortening the life of these devices. The quality of your inspection and workmanship is something other HVAC techs should closely observe and learn from👍👍Pride in the workmanship of the job is as important or even more so than the quality of the equipment itself.
That black feed wire looked like its insulation has failed, cracks everywhere from the disconnect to the contactors. Was that replaced or was it just an electrical tape and move on situation.
The price of them fuses, personally I would not leave them lying around. You know if another contractor comes around, he will use them and charge the customer for the fuses. After you bumped that fan, it hardly coasted any, it was almost like it had a bad bearing on something. A bearing going bad could heat up after time, overloading the unit.
In a lot of commercial buildings, for the amount of time just getting off the roof and back up would have paid for the extra set of fuses. That shape and size is relatively cheap compared to others.
When you have jobs like this being frequently voltage drop across the leg or one leg you want to check the main panel that operating the restaurant to see if they have a unbalanced electrical load
Sometimes they actually do fail but it's mostly caused by a combination of heat, pitted contacts and loose electrical connections. Remember "Lower the voltage the higher the amperage if Resistance remains the same." Plus lower city electrical voltages too. Very common in areas that have added businesses and residential areas. Instead of building additional substations, they actually LOWER the transmission voltage up where it begins around 7400- 1400 volts. Also causes murder on contactors and capacitors fuses and disconnects. It's a band-aid.
@@mackwest5308 : Resistance (inductive reactance) in an electrical motor decreases as it turns slower. The lower the voltage, the less power, so the slower the motor turns. When voltage gets too low, the motor will stop. A completely stopped motor draws a pretty high current (bad). On the flip side, overdriving (windmilling) a motor increases the voltage, and amperage can drop to zero or even go negative (a/k/a an alternator).
@@mackwest5308 The reason you're confused is because you think voltage is a conservative force. It's not. The conservative force is power, so if on the secondary side of the transformer the voltage was increased AND the current stayed the same, then the power on the primary and secondary sides are not equal, and you've violated the first law of thermodynamics.
@@mackwest5308 E=IR or I=E/R In general the current is determined by the load, not the wire connecting it to the source. If the wire is the load then more voltage means more current.
The thermal camera makes this call so worth its money for the customer and yourself. Good work finding all the things you did.
You always do such an awesome job of diagnosing the root cause of the problem, then properly fixing it. I’ve learned so much from you Chris, and I’ll be doing things the exact same way that you do once I’m done trade school and I’m out working in the field. I wouldn’t have done anything differently in this particular situation. Keep up the great work and thank you for another awesome video!!! 👍🏻👍🏻👍🏻
You probably would have replaced the cap with a potato
Thanks bud
@@66Ack that made my laugh
BTW It's nice to have the "Opening" back. It's got an 80's vibe to it. Everybody loves neon lights.
Thanks bud
Brother, I've been watching you for 2 years now, and you, as mentioned by many, are very thorough. I appreciate the knowledge you share with us.
Root cause analysis and lasting repairs, love to see it. Too many companies/people triage and never circle back (my experience in industrial maintenance)
Had calls several times and the customer was angry.
Looked up their service history and I hadn't been there from between 5-10 years ago!
🤣🤣🤣
Good that you replaced those incoming power wires when you replaced the disconnect (between disconnect and the contactors). They looked super cracked, seems like rainwater could have shorted 2 phases together. Thats something you should ALWAYS collect as info if fuses blow. How was the weather when the unit stopped working. Was it rainy, sunny, dry, wet, snowy, cold, warm etc. That gives a lot of information of potential causes, if the fuses blow only when its rainy and wet, you know there is water ingress into something electrical that is shorting it.
it's common for the outer clear jacket to get brittle, crack and fall off. I cannot say I've seen any that hasn't done that after 5+ years, indoor or outdoor.
Please also be careful you are not only invaluable tech you are knowledgeable and willing to share which makes you one of a kind. thank you sir.
The way you methodically check every failure point is fantastic. Other techs may have looked at those rubbed out wires by the indoor blower motor, fixed those, and called it job done. But the way you always look for every possibility makes me wish you were in my area 😂
I appreciate that
I will discuss this on my livestream this evening 10/7/24 @ 5:PM (pacific) on RUclips, come on over and check it out ruclips.net/user/live66AQTmLtKRE
With that large of temperature difference you should have seen some voltage drop across phase 1 of the disconnect. I suspect that you are not switching your SC-480 in to the lower range for AC volts.
For whatever reason when you turn it on into the AC voltage/current range the auto range settings do not go as low as the meter will measure. If you press the range button to manually cycle through the ranges you an get to a lower range that will properly show voltage drop across a disconnect or contactor. I recently picked one up for use at work as a Production/Facilities maintenance tech and found that it does not have enough resolution in its auto range mode to see small AC voltage drops but works fine when you manually select the lowest range.
Interesting I will look into that
I very rarely ever use auto ranging on my meters. I've built up a habit of setting the range I am looking for at the moment I turn the meter on. I have a distrust for auto range function on meters from using some of the earlier generation meters that have it. I also feel the response time on auto range is way too slow for some test applications. It's best practice to just not rely on it with anything past the most basic of voltage checks.
Thank you for fixing the music volume so it doesn't blast us...
Your Sporlan promo, then with your custom intro, FTW. It’s perfection!
Thanks bud
Great job, the fact that you took the time to use that unistrut on the junction box. A lot of techs would’ve just left it as is.
Thanks bud
Excellent diagnostic method!
Excellent video, Chris. Thanks for showing the lockout on the main breaker, keeping things safe is critical when working on equipment, particularly that which can seriously bite you both metaphorically and literally. Great job with the thermal imaging as well, something I'm surprised you don't use all the time as a means to see what is going on 'inside' the machine both on electrical and refrigeration circuits.
We change disconnects and a lot of the time just the internal parts do to repetitive on and off from operators locking out and checking equipment at our plant. They always seem to show a hot leg like you found on our thermal camera but rarely have obvious broken parts so I found this interesting. Always enjoy the videos and learn a lot. Thank you
One suggestion I have that comes from a household HVAC guy. If you do leave extra, working parts such as fuses behind put them in a bag and label it. He assumes that anything left around is something that didn't get cleaned up.
Good point
You have the best hvac videos in my opinion. Thank you for another good one!
Thanks bud
Here in the UK we wouldn't use connector (we call it a gland) inside equipment like that just a pvc grommet. As you know i love watching your videos because of the way things are done differently and things that are done the same. Sorry i've been missing HVAC overtime, been crazy busy so exhausted by friday night, and 2am is a little too late :)
No worries bud, get your sleep, we'll see you soon I'm sure
Great Video !. You are absolutely right about using the IR camera. My day job is engineering manager in medium sized research facility. We have instituted IR surveys using an outside IR shop. Started 3 years ago. "Hot legs" on fused disconnects do pup up and look just like what you show in this video. We are now getting a cheap IR camera to add in-house survey's to our PM program. Insurance companies really like this too !
That's awesome, thanks for watching
As an electrician, one thing I would never do is run three identical conductors without wrapping phase tape on them red and blue for the two phases on a 208 line. I even do this on single phase residential. if you did this before you disconnected, you would have less chance of having wrong phase rotation, and it also gives Assistance to the next person who opens that box so they know what phase each wire is that of course doesn’t mean that they were properly connected in the main disconnect, but at least you have some labeling scheme at your end otherwise love the videos and it has saved me a bunch in diagnosing my own systems.
Also take photos all the wiring before disconnecting anything.
Thanks for watching
Those rubber gromets with the groove in the middle work perfect for those holes if you really dont have a connector that works
Chris, I use a Kline NCVT-4IR volt tic with IR to do quick temperature checks on components and supply/return temperatures in the conditioned space.
You're absolutely right on the disconnect, and temperature checks are the first thing I do after a blown main fuse... I just use my Kline IR volt tic instead of a several hundred dollar camera.
As usual, beautifully described process, and thank you!
Thanks for information
I gave a one year warranty for anything I was paid to touch, parts and labor.
Went very well 99.99% of the time.
The failures were from a bad part.
Would be cool to watch you diag hot side problems nice to see you still got it 🎉
Thank you for adding the bonding conductor. Also as far as tightening stranded wires I tighten them than grab the conductors and wiggle them by hand to relax the strands and than tighten some more, works good.
Thanks for the tip
I concur, I always wiggle stranded conductors when tightening and always get a little more turn. Plus anytime I am in a tight box for the first time I check all connections first. A few loose wires popping out on you a few times and you learn to check before digging around.
Finally mastered the new intro. Kudos to you Chris!
Thanks bud
I bought the spigot/wand you use on coils and it is awesome for washing my truck! From mist to the strongest narrow beam, and the flex head, nothing better! Thanks for sharing about it a few weeks ago. Great channel.
Thanks for watching
just bought some tools from tru tech tools and used your code, thank you for showing us about them. i never heard of them before watching your videos
Great procedure. Thank you for these videos. I always learn something from them. I, honestly, do not know how you do it to run the company and make videos hahaha. I barely survive with just work. One thing I have learned recently is that wires can produce electrical arc when they are cracked. I, kinda, saw that some of the main wires had some cracks in there. Not sure how deep they are into the insulation, but that could have happened. I think changing the disconnect after using the camera was the way to go. The problem went away. That means the procedure followed was right. Thank you, Chris. Always learning a lot for these videos. I am very grateful.
All that has to happen is a brown out, or momentary single phase condition from the utility. Also bad blades in the disconnect, will cause the fuses to run hot, and go bad. It is easy to diagnose with a non contact thermometer.
Great video! At 4:06 pause the image at 4:07 YES the wire does look in BAD condition! Cracked sheathing at minimum and maybe a rub through underneath the above red wire.
It's really nice to see when you're measuring live high voltage circuits, you do it with one hand, it's a very safe practice. Probably it would be a good idea to mention it in some videos, if you haven't done it already.
Great video! So dang thorough! I had forgotten about checking temps of disconnect lugs. I have done this with an infrared thermometer in the past.
I will discuss this on my livestream this evening 10/7/24 @ 5:PM (pacific) on RUclips, come on over and check it out ruclips.net/user/live66AQTmLtKRE
You need to make a video on "motors dont just die"
If manufacturers would bother using acutal motor (magnetic) starters with phase, overload, OV and UV protection instead of just open contactors, their stuff would maybe last a little longer. But nobody in this bracket of the trade wants that apparently.
@@marikann9073 up next, VFD's on everything, cheap ones that fail from a crossed fart(lol)
bending and soldering unistrut.... thats a new one. I never even thought of that. but it looks like it worked well! Adding that to my bag of hacks =)
Yeah it didn’t look the prettiest but it worked
@@HVACRVIDEOS that unit didn’t look the prettiest. You made it work.
a little
observation ,when you place spare fuses ,indicate on the unit where they are,specially when there is no room inside the disconnects ,it helps a lot when your employee or yourself service the units
Good point, thanks for the feedback
Great job Chris. Big Picture!
Thanks bud
At 13:23 in the video the wire strands sticking out the bottom of the lug at the top of the disconnect for leg 1, look like they have a green tinge to them like they've got wet at some point, whereas leg 2 is dull copper. I'm wondering if this was the original problem and it had dried out by the time the tech got there.
Always enjoy your videos, super diagnostic process 😊
I read that to fast and thought you said super diagnostic princess, lol, thanks for watching
Awesome videos they keep me interested! Keep up the good work!!!!
Great video Chris! I use your videos in my Apprenticeship Training Classes.
That's awesome, good luck out there
Love everything you are the best.You are very educated.Love your videos so much
Thanks for that
Re: fuses going bad, they actually can do... cartridge fuses not so much but any fuses that are run close to their capacity will oxidize the fuse element and eventually blow. Probably a good thing the US code has the 80% requirement
Did you try reterminating that first phase? both before and after the fuse? Looks like it was loose on one end and caused it to draw more current bc of that. But yeah .. brand new box would fix it all too, especially if it was like this for awhile and drawing more and causing that one leg to overheat vs others.
Nice 👍 great videos...
may you make a video explaining how to wire RTU's using the electrical code and ampacity tables. im alwasy curious about the wire and breaker sizes in your videos for these units. And why they chose 45 amp fuses and alot of electrical questions. i know most of the info is on the nameplate but a video breaking it down explaining how you would wire, would be amazing!!!!! id pay for this type of knowledge too cause there isnt much on youtube
Great video. Thank you for sharing.
Thanks for watching
Love how thorough you are and would love the opportunity to work for you
Been in the field for 30 years live in Victorville I will be emailing you
For sure send me an email bud, thanks for watching
Love from Pakistan💖
I think I would possibly use Crimp Ferrell's on the stranded cable. I have found you get a better connection because the strands are all clamped under the screw
Professional and thorough! Thanks for the video!
Thanks for watching
If your company does the service full stop you gotta ask your employees who bypassed the economizer. Removing the wiring for the economizer was the wrong choice in my opinion, they aren't always great in every climate but the control of minimum damper position is key in many buildings to maintaining proper air balance. You've said before that the power is dirty and when you showed y1 + y2 jumped I knew a lazy or incompetent tech did what they thought was right by getting both stages on but they made a unit run nearly double the inrush current in a bad power distribution network when calling for cooling even with low load (y1 / one stage). Another thing to look at is the breaker because that unit had to have run hot and the line with the voltage drop might be losing power from a compromised breaker.
I've had fuses stickered as 30A before that one of the three blew on the control side, replaced all three couldn't find an issue, tried to pop the old fuses with a high end bench powersupply, one of the remaining 30's blew at 22 and the other at 21.
Quality control, its not like it used to be.
Your double and triple loop wire ties to isolate rubouts is obviously cheaper but I have a penchant for using loom.
Found a bulk variety pack of rolls of various sizes a couple years ago from an electronics wholesaler going out of business and still have a bunch!
Very nice
I will discuss this on my livestream this evening 10/7/24 @ 5:PM (pacific) on RUclips, come on over and check it out ruclips.net/user/live66AQTmLtKRE
I have a Hikmicro B01 and it is a fantastic camera for the price. It connects to my phone wirelessly so I can download images immediately to send to office or customer if needed
I'll have to check that out
I am asking because in the video the screws in the disconnect box are torque in foot pounds. Is it really foot pounds or inch pound.
Thank you for all the great videos . I always watch to the end for you. Don’t want a 10 out of 10 for you..
I've actually had a fuse (automotive application), go bad without separating within the envelope's sight area!
That's neat, I haven't seen that yet
If fuses don't just go bad and you did a lot of preventative work to make sure they don't blow, why leave extra ones? What would your expectation be for them to ever blow again?
Our bosses NEPHEW(he had no business being hired),was following me to an alarm on an electric fire pump. I found a short to ground on one leg.I told him to not touch anything,as I left the electric room,I heard a bang and the lights dimmed.He tried to change the blown 400 amp fuse,with his bare hands.When I walked back in,he was just shaking his arms up and down. I then asked him why, and his reply was,I thought maybe the fuse just went bad! Idiot,lucky to be alive!
Did he damage the contacts? Did he bill the client for the extra fuse?
So after destroying a fuse and the box, did the nephew or the boss realize that he wasn’t ready for the job?
@@denverbraughler3948Nope,25 years later ,he is still employed! Still cant do shit,makes me sick
Very lucky to be alive
He learned a very important lesson that day…
Great job. Bad disconnect will blow fuses as you know. Maybe myself the disconnect was problem all along.. however rub out may be a problem.
Good point, thanks for watching
Sometimes, fuses do go bad. Experienced it couple of times.
A plugged condenser coil causes fan motor current to go up. And the higher head pressure causes increased load and higher current at Compressors. (I am an Instructor for Hvac local Apprenticeship program).
This checks out
Yes I would have changed the disconnect box as well
Final comment, i tend to shut down the supply and use my fingers to find warm connections.... not owning a thermal image camera. But yes, one leg warm on a 3ph with no neutral is not a good sign, as you say on 2 legs is fine (sometimes)
Be sure to always verify your supply is de energized
@@HVACRVIDEOS Got the scars from where i locked onto 240v and only got saved by falling off the steps... i always verify, using a proving unit, approved tester, etc etc
@@HVACRVIDEOS trust me..I do. Verified voltage tester (either a test lamp or a solenoid voltage indicator, aka wiggy ) . Proved working with a known supply before and after the test. 415v doesn't take prisoners
Once bitten twice shy
You know how you take apart compressors to see what went wrong as an electrician i wouldve loved to see that disconnect get taken apart and see why that was heating up that was weird you tightened everything and checked the knifes and it still heated up what other connections are in there?!
Re: too much current on leg 1. Seems like all of your single phase motors were using leg #1 - would balance out more if the single phase motors mix it up a bit … motor 1 could be 1-2, motor 2 could be 2-3, and a third motor could be 1-3
Also remember, all the work you do is to push chaos away for some more time.
Chaos ultimately rules as it's relentless.
The temperature difference would it infrared it's a very good tool it's save you time and headache The maintenance on the service was done excellent except I noticed the evaporator coil was very dirty also if the building let's say the restaurant is not balance load so also you need to check the total load balance from the main box that operate the whole entire restaurant see if the load is balanced most of the time you have in balance in the building we try to balance the load we always tell them get the election the balance the load you will save a lot of headache
what happened to those euro style disconnects? those were nice. guessing the customer didnt want to pay for it
Walters electrical should be a try if you are looking for disconnects sir in the area for a good price as well.
Thanks
I have seen even with no actual short when the temp is high the fuses may blow or open when motors come on as they can pull 5 to 7 times the run amps.
Good point
I have a class RK5 60A Fusetron fuse that just went bad in a disconnect for an outdoor unit. Do you want the fuse?
The circuit is protected by a 30A circuit breaker inside the house which did not trip.
There’s nothing visibly wrong with the fuse; the caps are solidly attached. The other fuse is fine. They look like a perfectly matched set.
The meter shows 0Ω for one and OL for the other.
I appreciate that but I'm so busy right now I won't be able to do much with it
if this usually happens, i always would check the disconnect. Normally when i trouble shoot blewn fuses and could't not fing short circuits, i would check the disconnect switch before i start changing the wires. I don't like that junction in the pipe from the roof. when i pull cables, i always pull a full lenght from the panel to the disconnect switch. More junctions mean more hotspots for failures.
Good point
@@HVACRVIDEOS yeah. thanks. i had done a lot of electrical trouble shooting. and i always saved a lot of time, by looking at the components that are most likely to fail, according to my experience with this kind of equipment.
i also had troubleshooted electrical control wirering at refrigerator trailers and containers. And since the high pressure control was bypassed, i always looked at these. that saved a lot of time for me.
2:05 Was that the control board making those strange audible tones? Lots of odd sounds coming from it if it is. Have high pitched whistles and stuff in the audio. It must be bad even when the equipment is crying out in pain lol.
I'm wondering about the support for that box. You mounted it to the unit without any flexible connection. i thought that was frowned upon as there's nothing to absorb any vibration or movement. I thought that was why they ran flex cable from the roof to the unit was to handle any movement.
I will discuss this on my livestream this evening 10/7/24 @ 5:PM (pacific) on RUclips, come on over and check it out ruclips.net/user/live66AQTmLtKRE
I thought your SC480 have a phase rotation indication feature? Test before & after.
I also noticed that the line (1) feed wire looks like it's aluminum and the other 2 are copper. at 15:54
They were all copper wires
You've got a crazy amount of extra wire coming from that rooftop box. You only need 3 inches from the outside edge of the box.
Nothing wrong with having extra, plus if one of the lugs form the Polaris connectors comes loose and burns the wire I more than likely will have extra wire to be able to cut it back and fix it
I dislike the possibility of a connection coming loose.
It’s better to make secure connections that can’t come loose.
An ounce of prevention is better than a pound of cure.
Great channel. Smart man, and do a good job explaining.
Thanks for posting. Question why did you not clean the Evaporator coils?
No reason to think they were dirty, the system vitals didn’t indicate that to me
@@HVACRVIDEOS Thanks.
The copper on the incoming wire on "L1" looked very green compared to the other two. It's possible your high resistance was there?
I suppose that is possible
disconnect was not fine-it looked like that wire/lug was at 259°. that’s -way- over the 90°C it’s rated for. (and you could compare IR image of the replacement for confirmation).
Fuses CAN and DO go bad‼️Over the years the fuse element becomes fatigued due to deterioration, and heat stress from the current flow. I’ve also seen circuit breakers fail for the same reason❗️ Ambient temperatures along with high humidity, also play a part in shortening the life of these devices.
The quality of your inspection and workmanship is something other HVAC techs should closely observe and learn from👍👍Pride in the workmanship of the job is as important or even more so than the quality of the equipment itself.
I will discuss this on my livestream this evening 10/7/24 @ 5:PM (pacific) on RUclips, come on over and check it out ruclips.net/user/live66AQTmLtKRE
A Thermal camera is a fantastic tool.
That black feed wire looked like its insulation has failed, cracks everywhere from the disconnect to the contactors. Was that replaced or was it just an electrical tape and move on situation.
Yeah I replaced the wire but the cracked insulation was just the water proofing, the main insulation was still good but I replaced it all anyways
How come some units you work on have fused disconnects and some don’t? Is it a code thing in certain scenarios ?
Nice video, Cap can be down 25 percent.
Thanks for watching
The price of them fuses, personally I would not leave them lying around. You know if another contractor comes around, he will use them and charge the customer for the fuses. After you bumped that fan, it hardly coasted any, it was almost like it had a bad bearing on something. A bearing going bad could heat up after time, overloading the unit.
In a lot of commercial buildings, for the amount of time just getting off the roof and back up would have paid for the extra set of fuses. That shape and size is relatively cheap compared to others.
AC unit: the Italian job.
Fight against spahetti.
You definetly have the taste for this. Why manufacturer hasn't it?
Just starting video now - my guess will be short cycle caused high in rush current due to high pressure with lack of short cycle control?
Did you finish the video yet?
@@HVACRVIDEOSyeap I was wrong
Why do they use fuses and not either a MCB & RCD combo or an RCBO?
I will discuss this on my livestream this evening 10/7/24 @ 5:PM (pacific) on RUclips, come on over and check it out ruclips.net/user/live66AQTmLtKRE
@@HVACRVIDEOS Bookmarked it, and will hopefully watch it over the weekend
When you have jobs like this being frequently voltage drop across the leg or one leg you want to check the main panel that operating the restaurant to see if they have a unbalanced electrical load
Good point
Only thing I would do differently would be to add a conduit clamp within twelve inches of the disconnect.
I wish you serviced the units at my apartment complex. Wouldn’t have my AC break 3 weeks in a row 🫡
With no ground wire in service line, I would use a grounding locknut on the conduit.
I will discuss this on my livestream this evening 10/7/24 @ 5:PM (pacific) on RUclips, come on over and check it out ruclips.net/user/live66AQTmLtKRE
How did old School techs diagnose an overheated disconnect. Infrared thermometer?
Yeah that what I used to use, you can also shut off power and feel the temp difference with your hands on the fuses
You didn't mention it but, were all 3 fuses blown originally or only the leftmost hot one?
The far left fuse only if I remember correctly
Sometimes they actually do fail but it's mostly caused by a combination of heat, pitted contacts and loose electrical connections.
Remember "Lower the voltage the higher the amperage if Resistance remains the same."
Plus lower city electrical voltages too.
Very common in areas that have added businesses and residential areas.
Instead of building additional substations, they actually LOWER the transmission voltage up where it begins around 7400- 1400 volts.
Also causes murder on contactors and capacitors fuses and disconnects.
It's a band-aid.
I’m confused, how is amperage higher at lower voltage if following ohms law?
@@mackwest5308 :
Resistance (inductive reactance) in an electrical motor decreases as it turns slower.
The lower the voltage, the less power, so the slower the motor turns.
When voltage gets too low, the motor will stop.
A completely stopped motor draws a pretty high current (bad).
On the flip side, overdriving (windmilling) a motor increases the voltage, and amperage can drop to zero or even go negative (a/k/a an alternator).
@@denverbraughler3948 ahhh that makes sense thank you
@@mackwest5308 The reason you're confused is because you think voltage is a conservative force. It's not.
The conservative force is power, so if on the secondary side of the transformer the voltage was increased AND the current stayed the same, then the power on the primary and secondary sides are not equal, and you've violated the first law of thermodynamics.
@@mackwest5308 E=IR or I=E/R
In general the current is determined by the load, not the wire connecting it to the source.
If the wire is the load then more voltage means more current.
Shouldn't the terminals be tightened to a specific torque setting?
Yeah they were all torqued down