Copeland Scroll Compressors Can Run In REVERSE!
ฝัง
- เผยแพร่เมื่อ 22 ส.ค. 2024
- Originally recorded June 23, 2016.
My 4-ton Rheem unit with its Copeland Scroll compressor exhibited an interesting issue, and I lost cooling for a short time. There happened to be a power blip. Normally that's not much of a problem. However, these Copelands can sometimes make loud startup sounds, yet others do not. They can also make a shutdown sound. Yet others do not. If they make a shutdown sound, it is because the pressure in the system spins the scroll backwards for a moment when power is lost.
Now, if power happens to be reapplied at the moment the scroll is going backwards, the compressor will start running in REVERSE, and as such, the air expelled outside is cold and the air inside is warm.
That's exactly what happened. Power was lost, the scroll spun backwards, and while that was happening, power was reapplied, resulting in a backwards-running compressor. There are lockout devices available to prevent this sort of thing from happening. This is the first it ever happened (that I'm aware of) in 10 years, so I expect it's a pretty rare occurrence.
Should the compressor be left to run in reverse, no damage will occur, however the head pressure will get very high until the compressor cannot spin anymore. At that point it will thermal overload out. Upon restart, it will resume operation in the normal direction.
I have a Lennox Condenser Unit model HS26-048-5P with a Copeland scroll compressor and I have witnessed this happening at least three times with the latest incident occurring this month. The incident occurred even though I had installed a time delay relay with a “delay on break” function some eight months ago. The time delay relay is a “ICM Controls ICM203 Delay-on-Break Timer with 0.03 minutes-10 minutes” that was installed in the 120 VAC AC line circuit that feeds the 24 volt control transformer located in the blower. When time allows I need to check the relay again to make sure it is still functioning properly, but I suspect that it is still possible for a temporary dip in the AC supply to the house to be just right so that the relay or the time delay function in the White-Rogers digital thermostat does not react to prevent the reverse operation of the compressor. The compressor tripped out on thermal overload and would not restart until it was allowed to cool down for approx 1.5 hours. I did not want to use water to cool the compressor and wet the compartment etc. Took the condenser unit cover off and let it cool with ambient air flow.
Statement from the Lennox HS26 Series Unit Information:
The time delay performs no other functions. Without the delay it would be possible to short cycle the compressor. A scroll compressor, when short cycled, can run backward if head pressure is still high. It does not harm a scroll compressor to run backward, but it could cause a nuisance trip of safety limits (internal overload).
Thanks Keith! Others thought I was crazy!
Thanks, great video. First time it happened to my condensor I would not have believed it either until I read that statement in the Lennox manual. And after doing a number Internet searches I found comments about installing the "delay on break" timer to help minimize the reversals. FYI the first time this power blip occurred it also blew the starting capacitor on my neighbors condenser unit (not a Lennox unit).
I once had a thunder and lightning storm that caused a number of brief, rapid-succession outages, and was outside in my covered porch at the time, A/C was in earshot. I don't know if it spun backwards at all, but we must have had 4 or 5 blips within a matter of 20 seconds, but the compressor restarted each time.
I think our problem is related to the way power company operates the electrical grid in our area. Although I have no definite proof, I think they are constantly switching sources or doing other operations that cause these power blips. Every compressor reversal event I witnessed occurred without bad weather in our neighborhood.
I don't doubt what you said in the least. When this happened to mine, the weather was nice and clear.
Well, that's one way to make a heat pump! I've never seen one do that before.
The 3-ton Comfortmaker straight cool unit (with Copeland scroll compressor) here has never made that "ratchet" noise when it's done running. Sometimes it does run more loudly than normal until the system builds pressure. Then it settles in nicely.
I don't think most battery operated thermostats monitor the presence or absence of the 24 volt power supply. Putting a restart delay device in the condenser unit seems like a good idea, as the Honeywell Wi-Fi thermostat here runs entirely from the 24 volt supply (had to pull a common wire so it'd work) and has no backup power supply. Whether it's smart enough to delay a restart I don't know. I've always played it safe after a power outage and shut off the power supply to the furnace until I knew the power was on for good.
Thanks for the info Bill, didn't know you watched me! Yes, this was a rather strange phenomenon, but I'm happy to read that it's a temporary condition that can happen and is "normal". And like I said in the video, it will eventually correct itself once the compressor thermals out, so even if no one were to be home, it would be ok.
You'll often find me wandering around the channels of people who are watching my videos on TH-cam. It keeps things interesting. I tend to be something of a lurker, though.
I think it would definitely be amusing if the unit here temporarily turned itself into a heat pump.
***** As interesting of a phenomenon as this was, in the heat of the moment before I did any research on the subject, I was quite worried. Even though they say it doesn't cause any damage, it's operating in a different way than it was designed to. I guess when a machine like this fails it must have let the "magic gas" out!
There are some channels I lurk on as well, especially those with an inordinate amount of subscribers. That's fine and good, but I'm very honored that you watch me. Thanks again.
Well mine reversed and I got it on camera.
Yep, that is totally normal. We had a Rheem air conditioner that would always do that on shutdown. The air conditioner was 12 years old when we moved in to our house, and it was 24 years old when we decided to upgrade. It always made that sound the entire 12 years I had heard it run.
Thanks for confirming. Oddly enough, the season after this video was recorded, it wasn't making that shutdown sound any longer, and hasn't for years. When I first moved in, it didn't do that. Then one day it started, and just as mysteriously as it started, it stopped.
i commissioned a goodman condenser single phase M/N GSX130601BJ, S/N 2005155921. I observed a delay for a moment. my 410a pressure with a piston equalized. the rotation reversed. the copeland scroll shut down on thermal overload. i came back 24 hrs later with a sp-6 hard start kit. i started it up and it sounded like a bomb went off, loud bang. i shut it down and restarted the condenser with no further issue. in 25 years, i never had this happen. my partner and i looked at each other and said we heard a bomb and we're still alive. mind blowing.
I can't answer that. I still get non-believers that these scrolls can run backwards.
@@jaykay18 thanks, great post
@@tedallen9078 Thank you.
On a 3 phase compressor If the discharge valve isn't fully seated when it shuts down, the discharge pressure can push the scroll backwards. When the motor turns back on while it's turn backwards it can run backwards. There are no red valves in the scroll compressors to keep refrigerant from gong back into the compressor. There is a floating seal that acts as a valve. Seven the compressor shuts off the seal disengages from the muffler plate this allows refrigerant in the discharge chamber to flow into the suction chamber of the compressor. It is possible for the seal to not separate from the muffler plate and cause the discharge to flow back into the scroll and turn the motor backwards
That's exactly what I experienced.
A compressor runni g in reverse will never change from cooling to heating, he will just make noise and displace less gaz. If the airco switch from cooling to heating after a short outage, it means the 4 ways valve did switch.
I was under the impression the head pressure would increase and increase until the compressor stalls, at which point it would thermal out. Upon restart, it would turn the correct way again.
@@jaykay18 Not my experience for it to stall. I found they run backwards about 10 minutes until the shell temperature hits 165 degrees, then trips out. Along the way it makes some ugly bearing squeaking noises; I thought I killed the clients compressor while debugging it.
I can certainly understand the feeling!
Not necessarily reversing a scroll comressor does reverse the flow. That would make the indoor unit the condenser and the outdoor unit the evap. However some metering devices might have a one way check valve.
Per Copeland's app note AE1331, a single phase scroll compressor can reverse when there is a momentary grid power glitch of less than half a second. Compressor makes a terrible sound when running backwards and it will eventually overheat and trip protection cut out. Once protection breaker inside compressor resets it should start up normally.
Always good to have a power glitch timeout timer on compressor contactor relay coil. Copeland says their compressors doesn't need refrigerant to equalize pressure before restarting but the reversing issue is enough of an issue to have the power glitch timeout timer. You want to avoid tripping compressor's internal protection Klixon breaker as it will eventually fail from too many trips, requiring a compressor replacement.
P.S. I have found that some electronic thermostats with integrated power glitch timeout timers do not always trip when grid glitch is very short in time, allowing the compressor reversing issue to happen. They also require the 'C' 24 vac wire to get the power glitch detection.
Another item to watch out for is condensate drain overflow switches that just cuts the 24vac to compressor contactor relay. If they 'chatter' contact as water gradually gets too high it can cause the contactor relay to bounce off and on.
Thanks for the additional info. That was exactly the kind of power glitch we had. This happened one time, and one time only. They have since redone all of the power lines in this area, and there is almost never a power interruption now.
I have a client in a high rise condominium with a water source heat pump that did this routinely. Although in the case of his unit there must me internal check valves to prevent reverse refrigerant flow. It has a replacement compressor 2-3/4 ton model ZR32K5E-PFV-800. The power is interrupted, the scroll comes to a stop very quickly, then the scroll begins to spin backwards due to the internal pressure from the high side, then the power comes back on and the compressor runs in reverse for about 10 minutes until the external shell is 165 degrees, then it stops and sits for a half-hour to an hour. With no refrigerant flow to cool the compressor, it get really hot before it thermal trips. I replaced the original unavailable R22 recip compressor with a Copeland scroll. This unit, too, has ICM protective relay devices (ICN492 & ICM200) that didn't help so far. I am righting the fault duration limit to get better results - 2 seconds does not do it.
Turns out the contactor's contact disks were badly burned and not making perfect contact. Combine that with some vibration and the thing would quit for a second or less. The Copeland scroll seems to have higher inrush current demand. It degraded the 30 amp contactor rapidly. It now has an up-rated 50 amp contactor that I hope will stand up to the high current surges at start-up. New contact seemed to work until it didn't..
Nice story. That further proves this can and does happen. I was fortunate that I was home at the time it did that, so I could stop it before anything got too hot.
@@jaykay18 The external shell will hit about 165 degrees when it trips. I sat in front of the one I described above with a Fluke Digital Thermometer and contact probe rigged to it to get a temp reading just after it tripped out -- the reading was 165. I thought I killed it. I quickly packed the compressor in ice water soaked towels and basted it with more ice water to pull the temperature down. It sat a long time wet before it would restart when the contactor closed.
I can certainly imagine it got that hot--that is indeed pretty hot. I'd imagine it probably runs around 130 or so on a really hot day.
New tranes are doing this. They need a time delay to keep it from short cycling and running in reverse. Just saw this on a hvac fb group page. Seen it in person a couple times. Definitely annoying when youre trying to service it quickly and efficiently lol
I've had people swear this is impossible. Those who know, like yourself, are further proof that this is true.
Thank you very much for sharing this comment. It gives me hope!! I have a Trane XR 2021. It makes a loud noise once in a while and last for about 1minute or two. Or I shut it down and turn it back on in five minutes and everything runs normal again. Installer has no clew what happen with the unit. Called other service company and suggested to install a power surge protector for the AC unit to be installed right next to it. Do you think that would solve the problem? Thanks again any Thoughts will be appreciated
24. Brief Power Interruptions
Brief power interruptions (less than 1/2 second) may
result in powered reverse rotation of single phase
Copeland Scroll compressors. High pressure discharge
gas expands backwards through the scrolls at power
interruption, causing the scroll to orbit in the reverse
direction. If power is re-applied while this reversal is
occurring, the compressor may continue to run noisily in
the reverse direction for several minutes until the
compressor’s internal protector trips. This has no
negative impact on durability. When the protector resets
the compressor will start and run normally.
Emerson strongly encourages use of a timer which can
sense brief power interruptions and lock the compressor
out of operation for two minutes. A typical timer wiring is
shown in Figure 16.
No time delay is required on three phase models to
prevent reverse rotation due to power interruptions.
(Copied from Emerson Bulletin AE4-1299 R21)
More: Page11
Yes thank you, I've read it.
The power interruption happens so fast or with generator power transfer happening so fast the contactor does not drop out. The reason this guy's air was cooler coming out the top of the fan was due to the compressor running in reverse, obviously not the SOV, rheem/Ruud units SOV are de-energized in cooling. The noise he heard as well tells what happened.
I am that guy, and yes, you are correct.
my Amana with a Copeland scroll has this a few times when there was a power cut. Once I came home during a heavy thunderstorm to a loud humming/buzzing noise which I thought was the sump pump. However, it was not. The air coming out of the vents was warm. Then when I went outside I found it was the condenser. There was a powercut in which this exact same thing occurred and caused it to restart in reverse. Installing a hard start kit may help with this issue.
Thanks--there have been many who have told me that I'm crazy and this is impossible. I knew what I was seeing and realized why it was happening. To hear from others that the same thing has happened to confirms my sanity.
Hard start kits were installed, coincidentally, the very next month, unrelated to this particular phenomenon. Haven't had any other power blips since so I don't know if this will even happen again.
You have a bad check valve on that compressor. That is allowing the gas to flow backwards. So when the power failed the check failed and the compressor started in reverse.
You are the first out of almost 10,000 people to tell me that. Not that you're wrong, but I want to hear that from more people before I'd start believing it might be true.
I think Zeke is correct. From what you described it looks you were pulling vapor from the top of the condenser, putting the condenser into a lower pressure, causing the liquid located in the lower part of condenser to boil and absorb heat from the air moving over it. Acting like an evaporator. This could only happen if the check valve in the compressor allowed refrigerant to flow through it. I don't think it is worth replacing the compressor just to have a working check valve. What you should do is put a timer that will not allow the compressor to come on immediately after a brown out or power removal, and just live with the noise it makes when it shutdowns.@@jaykay18
What I describe above is when the compressor is running in the reverse direction.
Thanks very much for your input.
Zeke is correct. I corrected a unit that had that problem. Had iffy power I removed the refrigerant installed a check valve on the discharge line at the compressor. Got the check valve from copland. And ended the problem. And no scrolls don't pump backwards. That rattle is the discharge pressure pushing the scroll backwards for a second. If all that makes sense...
That sound is the compressor running backwards for as split second on account of the discharge check valve leaking by. If the compressor runs backwards it doesn't heat the house that is your reversing valve that controls that function not the compressor running backwards as a pump running backwards will not cool or heat. Yes this a year or 2 too late... lol
Yes it wasn't heating the house, but the air coming out of the vents was NOT cold. The air coming out outside WAS cold.
This just happened to my unit. We had a quick power outage while the AC was running and then the unit started to make a vibrating sound as if something was out of balance. Turns out it was the Compressor running backwards just as was described here.
Thanks Dave! I knew I wasn't crazy! We had a power disturbance the other day but mine managed to stay running in the right direction that time. But as you well know, it's certainly possible. Mine also made some sort of weird vibrating noise just like you described. Hey--the good news is you know that no damage occurred and this is a real phenomenon. Just a good thing you were there when it happened so you could stop it.
The 3 Phase Compressor won't run backwards on its own. What causes it to run in reverse is the 3 Phase Power Service from your Power Company. In the case of a power blip, power outage, the Power Company may make a quick repair to restore service quicker, but at the cost of temporarily reversing the Phase Rotation of their 3 Phase Service. Once their permanent repair is made, they check their Phase Rotation, which allows your Compressor to return to its designed direction.....any 3 phase motor or compressor can be reversed by swapping any two conductors on its starting circuit. Thats basically what is happening upstream of your residence in an emergency repair by the power company. They may be bypassing a downed transmission line, re-wiring a transformer configuration due to a bad transformer, any number of problems.
Good to know. This isn't a 3-phase unit though.
@@jaykay18 Oic. Interesting. Most Scrolls have a Discharge check valve which should allow it to hit internal overload quicker, and thereby not allowing it to heat your evaporator and cool your condensing coil. Also, is your metering device on your evaporator an Orifice or a TXV? I higher Seer unit would have a TXV which would close and not allow refrigerant flow reversal either I imagine.
@@timothymyers3072 I have no idea what it had, actually. I don't believe it's a high SEER.
Completely normal with the sounds of this compressor.. the old scrolls were extremely loud. And taking the batteries out will not fix this problem on the fast interruptions. Nor will any low voltage control delay on break relay , that is if it happens that fast.
Thanks. Yes, I agree, there's really no way to prevent a problem with such a quick blip. Fortunately, this only ever happened this one time, and has not happened since.
Hello, this seems to be similar to what I'm experiencing. Had a blower motor replaced and literally the next day a grinding noise started. When the grinding noise happens the cold air with stop blowing and the grinding will continue for 15 minutes. After 15 minutes the noise stops, which i assume is the condenser shutting off, but the fan will continue to run for approximately 30 minutes. The condenser will then turn back on and start cooling. About 10 ppl have been out to look at it but we are unsure as to watch the issue is. This is a reheem ac unit and even the manufacturer is unsure
The grinding noise is coming from the condensor, I assume. When this happened to mine, I could tell something wasn't right. The buzz or hum that it makes when normally running just sounded a bit different, like it had pulsations in it. After I felt warm air inside and cool air outside, I knew something was wrong, so I shut it off. I left it for 10 or 15 minutes for everything to settle down, and restarted it. It hasn't happened since.
Your compressor may indeed be running in reverse, which is not normal. It would likely need to be replaced. That's my guess.
@@jaykay18 ty
If that happens, here are the steps to making it go back to normal
1, unplug the thermostat.
2, wait for the unit to shut down comepletely. (not hearing condenser or air handler running)
3, plug in the thermostat.
If I'm around. If not, the head pressure will eventually get so high that the compressor will stall. It will either thermal out and reset by itself, or blow the breaker.
also, the problem is that the shutoff device (check valve) is probably broken. because it shouldn’t allow refrigerant to go the other way.
@@Zeddify No, it does.
th-cam.com/video/A7AMLAqiHB4/w-d-xo.html
i think some compressor may actually allow refrigerant to go the other way 🤔
The compressor maybe a COPELAND compliant scroll which has unique feature that prevents slugging of the puron and it is quite normal for it to make that grinding noise when turning off I have an AMANA that does it as well but because it has a sound reducer on the compressor you can't hear it make that sound and it does have a loud startup which only lasts about 2 seconds then it quiets down.
Interesting. I've heard that some of them do it, some don't. Sometimes it makes the noise, other times not. The smaller unit next to it doesn't make that sound.
Mine just does the startup sound.
Older Copeland scroll compressor models in the 7 to 10 ton range, summit models, have a fluid break to keep it from turning backwards during shutdown. The grinding nose is the compressor spinning backwards. Three can be certain circumstances where the fluid brake can't stop the backwards movement long enough for the floating seal to unload the compressor
I've got a portable air con with a rotary compressor that does something similar, when it's a hot day and it's had high pressure and you turn it off or it cycles off, the gas pressure is enough to turn the compressor over slowly, it'll make a 'thump... thump... thump' and the unit shakes, if you look down the tube hole you can see the compressor shaking... one day I'll catch it on video!
Nice!
It’s not the compressor running backwards. It’s the loss of power to your reversing valve. The valve reverses the flow of the REFRIGERANT cycle, not the compressor. The compressor rotates in one direction only on a single phase power source such as a residential structure. So, this entire video is incorrect.
I'm sorry, but YOU are entirely incorrect. Just Google it, Copeland themselves have affirmed this to be true.
Reversing valves don't exist on AC only systems. They only exist in heat pumps.
@@jaykay18 gotcha champ. By the way. What’s the model number of your Rheem outdoor unit?
@@mariovgomez1820 No idea offhand, and I believe the sticker has faded into oblivion after about 17 years.
@@jaykay18 well, apparently it’s not a heat pump, as you’ve stated it has no reversing valve. So the compressor running in reverse performs no compression action on a scroll compressor. So the result is zero compression which will produce neither heating nor cooling. Additionally Copeland as well as other scroll manufacturers advise that running in reverse will improperly lubricate the compressor resulting in failure. So it’s a little more than an inefficient heat pump. It’s actually not a heat pump simply because the compressor runs backwards and it’s actually catastrophically damaging. The reverse action of a heat pump has nothing to do with the scroll compressor...... it’s the reversing valve that changes the direction of refrigerant flow and thus expansion and condensation occur in reverse locations in the system.
My A/C just did this after a lightning strike caused the lights to flicker. Shut off power to unit for 15 minutes , turned it back on and now it's fine .
Yep, that's pretty much what happened with me. After it was off for a short while, I turned it back on and it was fine.
Yours is probably the first ac on TH-cam to see do that. Oddly enough we had a power flicker when ours was running although never paid attention to it I sometimes wonder if ours does it. We have the Ruud version of this but I've never seen a compressor do this. For that couple of minutes it was running in reverse like that you could call it a heatpump lol.
Yes, it was basically acting like a heatpump. I did a lot of research on this "problem" and saw a lot of people say "me too!"
+jaykay18 Actually this reminded me of my grandma's old gigantic carrier window unit would shake and bang in the window when you turned the compressor off for five minutes and turn it on and it would make a sound similar to this one turning off it would scare me as kid cuz I swear it was gonna fall out the window. But other then that it ran really well like I remeber when you would get close to the vent and breathe you could see your breath in the stream of cold air no lie my cousin and I used to sit in front of it and be like holy crap! it was great old unit woodgrain and pushbuttons and all!
Logan Musser My old Westinghouse 6,000 BTU from the 1970s did that as well. Huge clunk when shut off and the whole unit would shake. That's because the rubber mounts on the compressor had degraded over time, so it's not mounted on a shock-resistant base anymore. My "awesome dehumidifier" does that as well, the whole unit MOVES when you shut it off. Both of those had recips.
+jaykay18 Sounds like my my ge carry cool turning off. I only have three vintage airconditioners but the others don't do it although the old 1976 montgomery ward makes a good kick when ya turn it off. Heavy thing too only 600 BTU and the thing ways 102 pounds!
+jaykay18 Also seen the dehumidifire and I think that unit is a fedders because my neighbors have the exact one same knob and the hi and low fan switch and has the same start up sound and all and says fedders on the top of it.
Yeah copeland scroll compressors can be pretty interesting in what they do sometimes...if this was an LG scroll I doubt it would last through running backwards!
Yeah very true!
I would say it DEFINITELY wouldn't.
my grandpa's 4 ton Day&Night(ICP) straight cool has an LG scroll. when it shuts off it makes a hiss sound. ill have to catch a video of it
Willie Peck That would be great.
My 1 year old American Standard packaged unit does the same thing. It has a scroll compressor. Every time I have a very short power surge, the a/c begins to hum loudly outside and it stops cooling the air that is going into the house. I automatically turn it off at the thermostat and wait 6 minutes. I turn it back on and it runs normally again.
Thanks, I knew I wasn't crazy.
My scroll compressor will reverse if the power flickers just right. I put a delay relay into the 24v circuit but it did not prevent it from happening again. I can hear the growl in my indoor unit when this happens. I simply turn the system off for a minute and back on and it runs normally again. It is not a heat pump so there are no extra gadgets that can cause the problem. Someone told me there is a device that will detect a reversed compressor and prevent it. Don't know for sure.
There's a separate device that will mount in the outdoor condensor that will introduce a delay, that will work to prevent this phenomenon. I've only had it happen this one time, but thanks for assuring that this IS possible.
you just got yourself a heatpunp lol.
Sorta kinda, but I didn't want one!
+jaykay18 yea in summer its the last thing you want!
Help! I have a Liebert unit with a digital scroll that makes a horrible chattering noise and does no work with unloader sol either on or off. Can I bump it in reverse??
I don't know how you're going to bump it into reverse, but sometimes that can do it. If it's not running at all you probably don't have much to lose.
The sound is called a scroll compressor bark, both of my Fujitsu Airstage units
They have a label for everything these days. Thanks Jack!
No worries, are these units still running fine
Yes, absolutely.
How single phase can run in Reverse,,,,,,,,but i found a 199 psi low press and 290 head psi. Weird but scroll comp in Ruud split system system
It is possible, there are articles about it you can read online.
I don't think you can pump hot gas through a compressor in reverse how are you flashing your liquid into the comp ? Think about it, if it were to run backwards why wouldn't the scroll plate lock up with liquid from the condenser . I say no way . only a three ph comp can run backwards, it could have been in bypass .
There is no bypass valve in this, it's an air conditioner, not a heat pump. Here's exactly what I know:
1. The system appeared to be operating backwards, cold air outside, warm air inside.
2. While the unit was running backwards, there was a distinct humming sound from it that it never had done in the last 10 years, that humming was more or less a resonant sound. That's what immediately alerted me to something being wrong.
3. I've read several sites that people claim it happened to them, and the general consensus was that it could.
Regarding the scroll plate locking up from the liquid, for some reason this particular system doesn't appear to be under any sort of tremendous pressure while running. Many years ago we were out in the pool, the skies clouded up, and we had one of those freak thunderstorms during the summer. That one I remember in particular was very powerful; for our own safety we got out of the pool and took shelter in our screened room right there. After some thunder and lightning crashes, we lost power several times in succession. This very same unit was able to hot-restart itself without any trouble. I don't understand it either, I've had an A/C tech hook his gauge set up to it and it seems to be reading fine.
I have a similar unit with exact same issues. AC mechanic installed a time delay and the compressor some times still runs on reverse.
Sounds like the tech didn't effectively solve the problem. A time delay will generally prevent the issue, if it works properly. But if it does that just randomly, without a power disturbance, there is something else wrong.
Unless your unit is a heat pump, this seems pretty weird.
Weird, but possible. Fully agree. It's definitely not a heat pump, it's only an air conditioning unit, and has no reversing valve.
If you have any UPS devices in your home.. it will help clue you into blips in the grid. This happens to me a couple times per year... and seems to be linked to nearby home(s) losing power. I know this, because I can write down the time, wait 5 minutes, check the local outage map.. and sure enough. It must be some kind of transfer in the grid.
A sidenote is I seem to have quite a few contactor failures.
I have UPS devices around. This day, indeed, they kicked on to battery for that blip.
@@jaykay18 And I'm not sure there is really a practical way to prevent this.. If the stat doesn't detect it.. I'm assuming it has the caps to temporarily stay alive and to keep powering the 24V necessary at the contactor. Any standalone delay component at the condenser probably wouldn't see a 24V dip and/or wouldn't handle the amperage to be hooked to the compressor high power circuit. I imagine you'd need some kind of UPS for the outdoor unit.
I wonder if these delays could handle the amperage between the transformer and the stat.... That may actually be the sweet spot.
@@Swoliosis1 It's a fairly rare occurrence. This unit has started countless times since this video was recorded, and always runs the right way. We have also had power blips, and it stayed running properly.
My AMANA DISTINCTIONS AIR COMMAND HAS THE LOUD START UP SOUND AS WELL AND IT'S SINGLE STAGE.
OK, there's no need to shout about it.
Is it technically possible to make a heat pump just by having a compressor that can start in either direction?
Yes, but it's not very efficient. There are proper heat pumps manufactured for just that purpose.
So basically the power accidentally turned your aircondioner into a heat pump! Never seen this happen before.
Essentially, yes. Though in this case, the compressor was sending the refrigerant around in reverse. It only happened that one time, it was very odd but I remember it distinctly.
You may have non considerable. In your refrigerant, to fix this you may need to remove refrigerant replace filter drier and do a deep vacuum before refilling
As explained this is a *normal phenomenon* that can affect Copeland scroll compressors. It is uncommon that it occurs, and required extenuating circumstances for it to occur in the first place, but it can and does happen. Many people don't ever even know it occurred.
A real problem with Nest thermostats
There's no need for those to begin with. A thermostat has one job to do--to maintain a set temperature. It's in the name. Thermo--heat, or temperature, and stat--stay the same. If you adjust your thermostat up and down all day, you're defeating it's sole purpose. Turning your A/C up to a higher temperature during the day is harmful to your equipment. Not during the day, but in the evening when you get home. The evening sun is often beating down on the unit and your house, this increases head pressure and causes the unit to pull more current to do the same work. Plus, you have lost all of those degrees during the day. So instead of the unit coming on to cool back down 1 degree, it not may have 6, 8, or even 10 degrees to cool. They claim that air conditioners take about an hour to cool one degree. That could be 6, 8, or even 10 hours the machine will have to run to undo your savings during the day. Not to mention, many electric companies now have time-of-use plans that their customers are being forced into, with false promises of saving money. The problem is, the highest prices--almost double--are during the peak hours when many people get home from work, between 4PM and 7PM. So by adjusting your thermostat to anything but the temperature you want it to maintain, you are only hurting your equipment, and your wallet.
At 1:43 you said p[umping warm air inside and cold air outside? because the compressor was running backwards? Reversed rotation scroll compressor will not magically create a heat pump ! Not even if the units is a heat pump! Yes a 3phase scroll can be electrically reversed but it wont pump if it's running the wrong direction period. a single phase scroll can assume a reversed rotation if the scroll is rotating backwards due to pressure equalization during the off cycle and turns on while rotating backwards. (That's why the delay timer is there) It doesn't crate a a heat pump when this happens it just wont pump.
Yes, I wasn't trying to make like this was a heat pump. The fact of the matter is, the compressor did rotate backwards, and it wasn't making cold inside, in fact the air was warm, as in, warmer than it would be if it were working properly. Outside, the air expelled wasn't cold per se, but was colder than it would be if it were operating normally.
@@jaykay18 thats not what you said in the video! you should remove it because its just more misinformation that trashes up You tube. If you are not a technician you should not confuse others
I believe I was perfectly clear in what I said. I'm no HVAC tech, but I'm dangerous enough to know exactly how it works, and can do minor repairs like capacitors, contactors, fan motors, etc.
How this can happen? It used to cool house without problems, but now it run reverse? Did you check the pressure at suction line and liquid line?
It was because of the power blip, the compressor can ran in reverse. It's a possible phenomenon. Never happened again since, the unit works perfectly, and there's no need to check the pressures.
Copland scroll type 3phase 5ton compressor can run reverse. There was wrong phase connection. Changer the 2 phase line order s.
Watched the video again and listen when I said it happened after a power blip.
Does this thing have a reversing valve
Nope, it's an air conditioner, not a heat pump.
Wouldn't running the A/C backwards technically make it a heat pump?
Yep.
No... that’s not how a heat pump works. A scroll running backwards doesn’t pump
My lennox elite series heat pump makes the same sound when shutting off
Some do, some don't.
Hi man, I´m Fernando from Emerson Brazil Mkt team. Please, Can I use your video in Emerson Channel TH-cam?
Please give me a link to the channel.
This happened to my 2010 Ruud 3 ton unit
Yes, it's entirely possible. Others have tried to tell me no, so I thank people like you, bolstering my facts.
So it basically turned your AC into a heat pump
Essentially that's what happened, though it's not efficient at all that way.
Scroll compressor can be repaire or not sir
Compressors are hermetically sealed units. They are not repaired, they are replaced.
jaykay18 thank you very much sir
Hook a set of guages up to it watch your pressures
Send a set of gauges and I'll do that.
jaykay18 why don't you have a set of gauges? Are you a technician or a homeowner?
I'm a homeowner who knows the technical aspects of everything.
jaykay18 Yeah, lol! What's your superheat set at?
If I had some tools I could determine that! Can't find that out just by looking at it you know!
@jaykay18 th-cam.com/video/iPwWEkvFWac/w-d-xo.html do those start up and shut down noises sound like the ones in this video. And the if your thermostat is run off of a C wire and not batteries that time delay will apply
No, they make sounds like you heard in my video.
I'd have to check the wiring, I looked at it years ago but don't remember. The thermostat has its own time delay and will indeed wait to restart for 5 minutes I believe.
@@jaykay18 ok because the unit I was filming in the video had a Copeland scroll compressor in it also
I've never seen any compressor run in reverse before!
Yeah, certainly an oddity!
I have many times mostly on 3 phase scroll compressors
Jason Cureton That I could definitely see.
Well if your heat dies, there's always a plan B.
Plan B I had thought about for a long time. That plan was to retrofit the air handler with a really really power hungry electric element as backup heat. If nothing else, that would be a huge selling point if I were looking to sell, which I'm not. The peace of mind knowing you're not going to freeze if the heat goes out is extremely comforting, especially if the weather is already chilly.
Still thinking about it, probably never act on it.
That it is, even for me with a virtually endless tolerence for the cold.
I hate the cold weather. Always did actually. Now being grown up with everything broken and not working the way it used to in my body, I especially hate the cold.
Well I can see why you want global warming so bad.
It hasn't happened as much as they say it has.
Get a Emerson Sure Switch, problem solved.
While that indeed would correct the issue, it's certainly not worth the price. First off, this was a one-off thing, never happened before, probably will never happen again. Secondly, if it does, even if I were not home, it wouldn't cause a problem. Eventually the head pressure would be too great and the rotor would lock. Then, either the breaker would trip, or the compressor would thermal out. In the former case, I'd reset the breaker when I get home, in the latter, after the compressor restarts after the thermal condition has cleared, it would run properly and I'd be none the wiser.