The ECM motor construction and troubleshoot 

The ECMs are used to increase the efficiency of newer equipment to raise the SEER rating. Many of the newer furnaces and air conditioners use the ECMs. To tell the truth, the ECMs don't save much money, as they fail about when they have saved as much as they cost. But, as you can see, the end bells are repairable. Hope this helps. GFM

Thank you SO MUCH for your video. My Brother owns a large HVAC Company, and refuses to help me. With your & other videos, you've helped me save my furnace!

You are very correct when you say the motors rarely are the problem and the end bell is where the failure usually is. Out of about fifty or so I have come across, only two motors were bad. The rest was just an end bell replacement and it was up and running. Of the two that had bad motors, both of them was just one of the bearing assemblies was shot. I could of just replaced the bearing but in the summer in Az. it gets quite rushed to get the next customer up and running. It was faster and easier to just put a new motor in and go to the next unlucky homeowner. Thanks for showing this on your video. I found it very informational and enjoyed watching it. Cheers

Excellent video, G-Man! You're a natural teacher. Every time I watch one of your videos, whether it's about gas fired equipment or AC units, you're able to break things down and make the subject matter very understandable. Thanks for sharing.

I had a us motor class yesterday on ecm motors the rep said the ecm motors used to fail alot from condensation in the module thus making the modules now coated with the epoxy on it. Thanks for your videos!

Another great video. My refrigerator compressor is also use this type of motor except that the controller circuit is on a separate controller board. Temperature is the biggest enemy for these motors, causing MOSFET or electrolytic capacitors to fail.

Thank you for getting me started on fixing this problem! It turned out that all I had to do was replace a $9 thermistor but you got me started diagnosing the problem. Thanks!

Nice presentation. I really had no clue on the operation or the troubleshooting of the ECM Motor. I never heard of 3 phase DC either! Learned a lot on this one. I am going through all the videos on your channel that pertain to my job & the equipment I work on. The knowledge I'm picking up by watching your videos is going to be putting a lot of money in my pocket in the future! Thanks Grayfurnanceman!

When I got into the biz about $150 bought my tools. Now $1500 gets you started. Even including inflation it is necessary to have more and higher quality tools to work on today's equipment. Thanks for the comment. GFM

I am very lucky to have your technical help for my trade . God bless you .

When i got started it did'nt cost much but over the yrs i have spent a lot,buying for 410-a was alot,this yr,ive not been working i hit ebay wide open and spent a lot of money and not sure if i will get to use them,docs are trying everything,no good news yet,i miss it bad,im trying not to give up,its getting hard but still hanging in there for now,the vids on here help me a bunch,i got some new toys if i do get to go back,cant wait to try them out,thanks a lot for the vids,keep em coming!!!!!

As in many other energy saving devices, they save energy but do not save money. The increased cost of the product mostly will eliminate all cost savings. I will say that the true ECM motors seem to last longer than the X13 motors. I have not had too many problems with the X13s but others I know have many. Unfortunately, they will probably change the motors so that the testers will not work before we have paid for them. So much for grumbling, it is the world we work in. Thanks GFM

100 years old technology. This is just off the shelf 3-phase AC induction motor hooked up to Variable Frequency inverter drive (VFD) which use DC pulse width modulation to drive it. The same tech we use for pool pumps since early 2000's in compact for factor. Good technology, 3-phase is the only correct way to drive induction motors, not single phase capacitor crap.

These Electronically controlled motors have shown up in all applications these days .First thing I`ve disassembled that has these motors in was a VCR that drove the capstan and the spinning head that was in 1987 then seen them in computer fans like the one you shown If hooked up to 60 HZ ac the 2 pole unit works as a synchronous motor running at 3600 RPM as in a plug in electric clock

Daryl Brinkley - Your video was very helpful for me and very easy to understand Thank You

If the motor stutters under power but does not start, there is a problem in the electronics in the end bell. If there is resistance to turning when the power is off the bearings have failed Most failures are in the electronics. The end bell can be replaced or repaired if you have the ability. Check out the video at ECM speed control repair

Good Information, Thanks GFM, Hopefully someone will make a tester for theses bell ends to have in the van, like a capacitor tester if we are going to see a lot more of them. Sounds just like inverter technology as in them ductless compressors must really save energy or manufacturers would not bother. BTW; To get a rebate in Ma. the new furnace has to have an ECM, I assume ... because you'ld be now saving electricity and gas

GFM, Genteq says that the epoxy in the module is to protect it from water damage. Although it keeps curious folks from digging into their equipment too ;-)

My very first encounter with these motors was with a mushroom-style downblast exhaust fan on a high rise residential job. I started the fan on its toggle switch and hearing how slow and soft the fan sounded on startup I honestly thought there was something wrong with the fan or the voltage supply was incorrect. Upon taking off the lid on the fan, I see a small soda can - sized motor. I then realized its an ECM motor. Since then, every job I have come across has started using these motors. The only equipment I haven't seen these used yet is on Cooling Tower fans and hydronic pumps.

what i hear the more is the price to replace them ! i am retired long time now but i remember 900 bucks was the price at one time ? i would install a relay and use the old style motor because of cost for the customer ,,,,now in 2019 just watching vids i dont know how its done now days ? ,,,,nice job on the vid

Great video. Only issues we have found is that you have to make sure the static pressure/airflow have to be right.

The tesla500 ECM vid is an excellent video!! I had never thought that a shorted winding could cause the same symptoms as a bad bearing. Thanks for the comment. Merry Christmas GFM

well done the motor is controlled by pulse width modulation off the dc buss just like a vfd does; the mosfets control the pulses, so it is indeed a 3 phase dc motor

Something I have tried with the Carrier 3.0 ECM GC08. After I have had to replace the ECM module 4 times in 8 years, at the cost of $200.00 labor while under warranty. It has failed again. You get an error 41 and 44. Cannot communicate with the blower and blower motor fault. I just got so frustrated when the Carrier people will not let me exchange the defective module for a good one. Have to have a Certified Carrier Technician. So, I took out the ECM module and put it in the oven at 180 degrees for 5 hours. I then replaced the module. I has been running now for three days. I suspect moisture intrusion. They will tell you to make sure the two connectors are at 4 o'clock position or the 8 o'clock position. Make sure the harness is routed below the two connectors, so the water won't drip into the connectors. The module is potted, so there is nothing you can do. By putting the unit in the oven you evaporate the moisture in the unit and it works. How long it works is anybody's guess. You will pay over $1000.00 for a complete motor replacement when out of warranty. I've had one technician recommend putting a surge protector on the harness going to the ECM. It's been my experience that these modules are not reliable and very costly. If your module is already not working, see if it has a moisture problem getting past the potting material. Mine fail regularly every two years.

Trane distributors have a tester for their ECM end bells. Unfortunately, their reliability has not been really good. They do save energy. GFM

Absolutely. You will still have to start it manually. Thanks for the comment. GFM

yes the world we work in is all about the money but we still have to work if we want to live in it. but if i can afford it and it make my job easyer i will buy it. i also bought several tools to take it to the next level of repair,the sman3 is 1 of my best investments.thanks for all the gas furn. videos,they help me a lot!!

To the point, and keeping it simple!! GREAT instructional video!

Hi GFM, Thanks for this great video! I just got this section in the reading material and this video really helped out allot. HAVE A HAPPY NEW YEAR!!!

i have 2 X13 motors here that the magnets came loose on 1 and bearing locked on the other,i have the zebra vz-7 to check ecm motors great tool but it will cost ya to buy one but it does a great job and this is what hvac is coming to so i invested in it,great investment,you have to buy the extra harness to ck the x13 the evap. and cond. use different harness thats were they get ya everything is about the money these days,know what i mean,thanks for the video

Excellent video GFM. you're very knowledgeable man.

Sorry, your comment was in spam. The windings are 3 phase DC with a perm magnet rotor. The 3 wires being checked are the windings of the DC field. AC goes into the end bell, pulsed DC comes out to the 3 wires. I hope this explains. Let me know if it does not. GFM

I was a VCR tech for over 20 years , an ECM motor is very much like a drum motor in a VCR just a lot larger .

I don't doubt that. Capacitors that originally would operate 60,000 hours now fail at less than 20,000. I am sure you can expect lower quality in newer ECMs. Thanks for the comment. GFM

it goes from A/C to D/C back to A/C for better control and cleaner power.

Thanks for the support. GFM

The bridge rectifier is also replaceable. I stepped up max voltage on the one I ordered for a little more longevity. My thermistor was was shot, infinite ohms. So I figured it's best to replace them both and beef up the board with some extra wire when I solder them in. Putting a bigger heat sink and some thermal paste may be a route I go as well.

Some of the end bells can be tested by the distributor. Hope this helps. GFM

They do run on less power due to the fact that they run at variable speeds to match the load. GFM

If the motor feels like it's a servo motor, ie has notches as it turns you have a short in the windings. Not as scary an issue as it sounds. I opened the case and found a burned spot on two wires as they run around the top to each coil. Carefully separated them and wrapped a bit of elect tape. All fixed for pennies instead of $700.

I think I found the answer to my problem at 3:55 in this video. When turning on my fan kicks in the right direction but then in the opposite direction oscillating back and forth.

Cool video, thanks a million.

I changed (swapped) the ecm module on a X13 motor and it fixed the problem

Great video! Do you know what voltage should be going through each one of those phases. Currently checking on my 1/3 hp 2.8 amp 682 rpm champion 3ton heatpump condenser motor. Does it step the voltage down from 220? This unit is only 3 months old, after a thunder storm power outage, I noticed the condenser not running an hour later, I came to find out the unit had already shut down once for overheat, it turned back on but only compressor , not the fan. I unplugged the 3 wire plug that goes to the motor to test the voltage while the pump was running, I got 35 volts on all 3 wires, then plugged it back in and the fan came back on like normal. What happened? Is it fine or did something possibly get damaged? Thank you

No supply house that I know of does not have a tester nor do they sell just the back end. I agree with you in that all the motors that I replaced , the motor part is good. I just wonder what is the main component that goes bad on the back end of the motor. It’s a shame I can’t just replace the back end part.

Thanks very informative video. Just had a question. When the ecm is plugged into the blower it’s hard to spin the blower but when disconnected you can move it like it should. Does that mean it’s a bad ecm?

You might look at Zebra instruments. Johnstone supply also has some tools for testing. No endorsement here just availability. I believe GE also makes a tester. Be sure to check out the link in the vid to the thermister repair. Most failures are from this part. Hope this helps. GFM

So now the newer blower motors are a 3 phase DC servo reluctance motors. Like in the newer washing machines. Which have been renamed ECM for short. In a nutshell they save a lot of electricity.

you need to talk to DrZarkloff he says you can not change the end bell instead you have to replace the whole motor. thanks for all the videos they are very helpful for me as i am a student in the hvac field

Thank you so much 👍👍

I would love to know exactly how it works. I am assuming that the capacitors and the inductor coil are used as a filter to get the ripple out of the dc that is generated. I've heard that it has a current limiting thermister to limit current in the rectifier circuit. I call it a rectifier circuit but it has mosfet transistors in it and I know that they use anode and cathode saturation to control those. Anyway, I would love to know exactly how the circuit works. It would make it much easier to troubleshoot. Keep me posted. and thanks!

My ecm 2.3 motor is stuttering, not wanting to spin. I pulled the motor and ecm. The ecm looks clean without any burn marks and the thermister reads 1.7 ohms across the leads. I checked the motor leads for shorts. No shorts. Then I checked resistance between each of the leads. Mine were not the same. I had readings of Black/Blue 1.2, Black/Organe 4.8, Blue/Orange 4.4. I suspect my windings are bad? I suppose it could be motor and ecm. Don't know of a way to check the ecm separately.

if your Variable Speed Zebra says your module (end bell) is bad then check the resistor (its about the size of a nickle up to a quarter.) in this video you can see a green one at 1:29. check that resistor for continuity. if there isnt continuity you can replace that resistor with a soldering iron and a new resistor for about 25 dollars (soldering iron not included) . this saving you or your customer hundreds of dollars.

The green disc MOV is what I usually see going out and after a bad storm as well. There is now an inline MOV which I guess is rated just below the internal one but not sure.

this thing would make a good generator wouldn't you think? youd have to mod it of coarse but looks like a good core for such a thing

I am a audio video tech and have worked Vcrs since they came out ,this is the same thing ,on a large scale, as video drum motor .

Thanks for posting. Are the mosfits servicable/replaceable? I have a ecm variable speed motor combo that isnt ramping up to high full speed. Its stuck in low. It attempts to go to high but fails. Thanks for any suggestions

I just replaced one that had a snapped shaft. It beat the shaft against the casing until it worn about half way and then it snapped. The squirrel cage was intact. I opened it and the magnet inside shattered. I never seen anything like that before.

This one is 1 hp. However, it is used at lower hp in many applications.

I can't say about availability outside the US. I don't see any reason it should not be. The one I show is GE. Emerson has one also.

Thanks Now I understand it better.

Nice audio & graphics.

I dont have one right now to check, but I think around 330 microfarad. This will be different for the different sizes. GFM

I'm pretty sure you said you were checking continuity to the windings? Actually you were checking resistance when you read that each winding had 3 ohms of resistance which, just like a 3 phase motors windings would read if they were good, all 3 would have the same resistance.

Excellent video 👍 but there’s one problem that I’m having that the motor Sometimes doesn’t come on but the outside unit comes on then a half hour later the motor turns on what can that be ,

Sorry about not responding. You were in the spam. However, I would have told you to replace the motor. There is nothing that you can do to fix these. GFM

So I have a 1/2hp 1 phase just like the motor in this video. The fan motor was studdering to try to start, This is an expensive motor, My question is, when I turn the shaft of the motor by hand should it spin freely? Mine seems to feel like magnetic resistance. Thanks in advance. All of the windings inside look brand new. Its a GE motor off a lennox air handler 14 seer.

Nice explained video.

the motor actually runs off ac,ac comes in turns to dc a pulse width modulator ic drives the mosfets to a variable three phase ac signal to the windings

Thanks

that's some good info GFM thanks

Does ECM multi-speed have the same type of windings in your video except for the end bell difference?

You will have to explain "cogging". GFM

thank for this good video...

Take another motor and hook it shaft to shaft to this one ,turn it on ,measure the voltage at you leads . I think you will have a three phase generator .

Thanks for your videos - I have a carrier unit with an X13 ECM 1/5 hp 230v GE motor - and what it keeps on doing is with the fan switch in the on position, it will run for about three seconds and then shut down - run for three more seconds and then shutdown again - with the blower door removed it will run much longer before it shuts down again. I don't have an ecm tester - is there anyway to tell if it's the fan control board or the ecm module?

Sorry your comment was in the trash. Let's hope the new module is ok. And yes the ohms should be the same on all windings. Could also be shorted to ground. Gfm

thank you very much

Hi, does the furnace control board sends AC or DC to this ecm motor through the 4 wire connector? Thanks

All great info however at 7:20 are you not just checking the end bell board, not the three phase dc windings? AC in/DC (pulsed) out, right? Seems the windings would be well isolated from the three exposed leads by that mosfet chip and associated electronics. Aye?

always interesting ...

Direct current three phase? There are no "phases" when using standard direct current. This is a permanent magnet three phase motor. The direct current is received by the VFD and then rapidly switched on and off making a rotating magnetic field effectively making it a square wave alternating current. If you took this motor itself and supplied the appropriate sine wave three phase voltage, it would theoretically run. In essence the ECM is like a glorified computer cooling fan motor, which is also AC.

I have an ecm that keeps cogging back and forth during cooling or fan only demand. What's up with that? I have tested the windings between each other at 10 ohms. The black terminal on the control board that connects to the corresponding motor winding was overheated and black. I cleaned it, re-installed and tested the same - not working.

Thanks, very helpful. I removed an ECM blower assembly from a Carrier unit and would like to use it for a shop fab. Do you possibly have any information about wiring the motor for 110vac?

How many volts DC are these motors? Btw I have an X13 that’s 240 volts.. I have the end bell as well as the control panel. ( the control panel (pcb board with transformer and wiring to the thermostat was mounted on the side of the squirrel cage)

One thing to mention if they send you one that is running in wrong direction,(Just switch two of your motor leads.) I've had a couple time that the module were backwards and when you call the supply house, they will say that's what that model number calls for. Quick fix and on your way

The motor is not reversible that I know of. So if it goes the wrong way, the ECM end bell is probably failed. GFM

What is the value of the dC voltage used to drive the motor windings?

I have a X13 GE motor thats got a bad module. The A/C man says its going to cost me 800-1000 to replace. That's crazy!! My question to him was....will he just wire in a old capacitor start motor like the old style motors and he said he could for 300 including new motor. What is your opinion of this? I'm not concerned with saving electricity but saving hundreds of dollars and ease of future headaches! Thanks. I really look forward to your response.

I have a 2.3 ecm motor 1/2 hp, that I replaced a thermistor on. When I take the end bell off there is not cogging in the motor, when I connect the endbell, cogging. What is this an indication of?

Is it possible to hook this motor up to a three way switch so I could use the highest and lowest speeds? I'm looking to retro fit it into my shop air filtration system... do you have any info as far as how I would go about making this work as far as wiring goes? Any and all help is greatly apprieciated, since this seems to be a bit more of a process than the last motor I had installed ... thanks!

Same motor, module as my rc esc and motor also dc 3 phase

The Emerson UltraTech Variable Speed Motor Manual says to check the voltage between pins 1 and 4 of the communication cable/connector (the one with 4 pins), should be 9-15 VDC. But I've measured 3.3 VDC coming from two different PCBs (PCBJA103). Any experience or comments about this?

Where can one get a replacement end bell module for a Goodman/GE ECM motor?

So this would be saying that I would need a circuit board element to complete this small puzzle I have here , so that the board can acomidate for the amp draw

Sometimes you can tell the end “bell” (i call it the module) is bad, by pulling it off and looking, sometimes that little link thats blue or green, will have a burn mark and the solder will be broken.

I have an 8 y/o Trans split system that uses an ECM on air handler motor up in attic. It's been cutting out when outside ambient gets over 90 F and then resets and runs normally when attic cools off. Are thermal intermittents common with this setup? Note: Thermostat not issue - R - G jumpered at air handler and still cuts out.

Great video! Is ECM a BLDC motor that has a built-in controller?

Probably the end bell has failed. Unless its an X-13, the end bell can be replaced. GFM

I have an issue where the motor is not spinning at its full rpm, causing the unit to ice up. I wonder if its the end cap he speaks of?