Split System DC motor testing
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- Опубліковано 4 сер 2016
- Indoor unit split system DC fan motor has been interrupted in a testing rig to show the various power inputs that drive the motor. Please check with your brand manufacturer for testing methods associated with your model from service manuals. The information in this video was believed correct at the time of creation. This is also showing Australian power supply/frequency and may not match your country of origin.
Filmed on mobile , no tripod so moves around a bit.
This was filmed in controlled and safe conditions, live testing is never recommended.
PS... These meters are TRUE RMS, so the voltages from the rectifier are correct, we have a couple of types , my video said they were not. Sorry.. Fluke..... but you can see we support you :)
Dear Dennis,
I watched your video and liked it a lot.
I,m a brazilian Guy who is trying to get alive fixing some air conditioning machines and PCBs.
Your information is very nice, helps a lot a technician that want and need to test this device. In Brazil this kind of information is very hard to get.
Thank you !
Your welcome Alexander and thankyou. I will be creating more vids soon
Hi Dennis, many thanks for your super information and helpful video with clear explanations. My LG ducted split aircon ducted aircon (model B55AWYU362 with indoor unit B55AWYN7G5) has developed CH10 error recently. CH10 points to loss of indoor fan motor feedback signal for about 50 secs and shuts unit down. A reset on the breaker clears the error but similar error developed on restart.
Some checks and troubleshooting:
- checked fans near the indoor unit. Fans were running ok, without any abnormal vibrations or abnormal noise.
- manually rotate both fans and both were spinning freely (nothing is seized)
- cleaned motor driver pcb with isopropyl alcohol snd checked connections. Nothing abnormal visually. Started aircon but tripped on similar error
- Suspected motor driver pcb to be faulty and replaced with a new pcb but aircon tripped in similar manner with CH10 error.
- There is another pcb next to the motor driver pcb and assumed this to be healthy
- with the above observations and after watching your video, I suspected the feedback signal from one of the 2 fan motors are faulty, causing the trip after around 50 secs.
I’d appreciate your advice on the possible issue and next steps. I assume the pcb next to the motor driver board will not cause CH10 but not sure if this is correct. Thanks
CH10 on an LG is a fan position lock fault. Simply put the DC fan is not sending back motor telemetry on rotation. This is either a fault with the pcbs ability to send a reference signal voltage to the motor or the motors ability to send back the hall effect signal in due time. Things like dry joints in harnesses or cable's can cause this too. The fan motor has a driver board, this is where command and response occurs. Smaller units are all integral to one outdoor pcb but some larger systems will have a separate fan driver. PS you cant spin a dc fan motor with a blade on it, as it will give weight ballast to faulty motors and make them seem OK.. Try it with the fan blade off and see if it feels notchy while unplugged from the board. This is a sign of internal issues mechanically. Good luck
@@whatwoulddennisdo7243 Thanks Dennis. I reviewed my troubleshooting steps and realised I have only 100% verified one of the 2 motions were spinning when aircon was switched on. The motor at the further hasn’t been verified. I did a check on this yesterday and found the fault - that motor wasn’t running at all (failed). Getting a spare motor now. Cheers
@@whatwoulddennisdo7243 does the pcb send a reference signal via the feedback wire or does the motor take voltage from the high DC voltage wire and send a little bit of it back to pcb via the feedback wire?
Thank you
@@LC-qi5ff The single phase dc motors use Vcc control voltage and send motor position feedback via the hall effect ic to the pcb to give it a speed reference. All the pcb driver will do is increase or decrease command voltage until the speed reference or tach signal meets the programmed speed set by the designer. These motors have multiple operations going on at once. See the multimeters
THANK YOU VERY MUCH SIR
WITH INDIAN SALUTE🙏
You are most welcome sir... thankyou for viewing
Thank you for the demo. My Daikin fan motor of the outdoor unit not let the PCB start up. When I disconnect the fan plug the diagnostic LEDs go on. In the motor the blue and brown wires are shorted internally with each other. My question is if this motors can be repaired? ... You answered down in the other comments.... Not serviceable. Thank you.
Hi Dennis, I am trying to run a motor just like this 325V, 1amp fan continuously without it being connected to a PCB fully (or bypassing the PCB logic) to use only the fan portion of the mini-split (I will circulate glycol/water through for air cooler application). I'm therefore wondering a few things: is the 325v always on such that I can use that from the PCB board output? Also, would I then just need to interrupt the 3v-6v "speed/on" control and input 6v from maybe an external AC to DC transformer? I guess I would keep the position sensor variable voltage going back to the PCB. Basically, is this mode of operation considered the heat-only mode, where it doesn't look for the coil T1 and T2 thermistor temperatures (ohms). Lastly, I was going to try to use another separate 12 or 24 V transformer for the 3rd S3 power input to the "evaporator" unit (Positive connection only since I don't know what to do with the common neg side). Any comments as to whether this could work before I buy/try stuff would be greatly appreciated! TY!
Wow that sounds like too much work to me, Have you considered a simple EC or electronically commutated motor that converts AC to DC operation and can also use a variable input. Dont try to circumvent manufacturer logic on an established system.These motors you see are made by common parts manufacturers and are setup by design speed needs by the aircon manufacturers. Once you try to bypass sensors on systems , they detect each other faulty or they cause other operation glitches. Whatever your planning, I suggest you come up with something new and independant. My vids show how the logic works to correct manfunctions
hi , its very nice ..... I have a question about such kind of d c motor control ......as there are many universal pcb available for the a c motor used in the split indoor can I have some universal pcb for such d c motor ...... pls reply
No this is is dedicated DC using 270V DC from a built in rectifier on the indoor pcb. AC equivalents use phase control motors
Super informative video mate, really appreciate this. I'm currently taking a deep dive into troubleshooting my LG split system and fault codes have noted a BLDC motor lock on the outdoor unit. Mainboard voltage measurements seem to check out, with 15VDC, 330VDC and control voltage apparent during boot. Would this indicate the PCB is in fact fine?
I've ordered a new replacement motor (seems to be a revised model ending with 'Q', my suspected faulty motor is a 'B' variant) so I'm hoping this will fix the issue. In your experience, if the mainboard checks out, what is typically at fault with these motors? I've tried testing the motor on the bench just by measuring voltage across the rotation pulse output and 0v reference and spinning the shaft by hand, the voltage seems to climb?
Thanks again for the really informative video.
The most important facts are as follows,, 1 you have the high DC , and 2 you have a control voltage VCC. The fan motor has to return a tach signal through the hall effect. If your unit is putting out a command voltage , then most issues are with the fan motor.
@@whatwoulddennisdo7243 thanks for the reply. I ended up repairing the system which turned out to be a faulty IPM. A Zener in the path had also shorted. Part for my replacement: au.rs-online.com/web/p/motor-driver-ics/7395080/
Cheaper than a $700 replacement main!
Hello, great video. I am a HVAC technician here in New Zealand and have been searching for a universal test tool just like this for troubleshooting heat pump system / dc fan motors. Any chance you could point me into the right direction? I see a few people on Oz using them. I cannot seem to find them anywhere.
Hi, this rig I built to interupt the signals to a dc permanent magnet motor so I could demonstrate fan harness to pcb driver testing positions. normally too difficult to test due to small test points. Many manufacturers use similar motors but voltages and pin references change so this one was made to a specific well known brand. I use it to train students in a safer manner. Check with your brand manufacturer and see if they have a comms tool that can display more motor telemetry. These days its all reverse bias resistance tests from given pin points.
IF YOU POSSIBLE, HOW RESISTANCE OF DC MOTOR IN CLOSE CONDITION OF MOTOR PLEASE
There are resistance tests possible but you must check with each brand manufacturer for the specific testing methods and outcomes. You will need their service manuals or obtain technical support.
Very usuefull thank you, about position signal it is actualy an rpm feedback. This why the board will in or decrease the control voltage according to the feedback.
Yes, the position is based upon hall effect sensors or rotary encoders embedded into the design
Hi,
how to check resistance for this kind of motor?
That depends if the manufacturer has them avaliable as a service check item. They will likely be several megaohms or even open circuit on some tests. Many do so check with the AC brand service centre or technical support staff
My unit is Lg inverter aircon and motor for blower is DC310V SIC-37CVL-F130-4A, when I pulled out the motor I noticed when I tried to rotate it has some resistance, when I check the bearings are ok but once I put it in the motor resistance to rotate appears again. Does this indicate a problem? It should be free turning with no resistance right?
It is normal to have some resistance to movement in DC motors as the permanent magnet when turned acts as its own braking force. However if it feels "notchy" such as its gripping and unsmooth to turn then this can indicate internal problems. You will only get 1 to 1.5 turns when you spin the motor shaft freely unweighted by hand which is typically normal. When you have a fan blade connected , this adds ballast and makes it seem easy and free.
Hi, Dennis this is very informative video and rare like a gem, i find your web site to.
I have very similar BLDC motor from toshiba daiseikai 6 AirCon and all voltages on board Vcc 15v, high dc 310, and command voltage is swinging from 0 to 5v in two attempts and motor wont start ! Everything imply that fan motor is bad.
I have idea to cut plastic case in circle like you and repair electronics inside? I assume that is some electronic problem on board inside motor?
Here where I leave tech. support is not so good and I am struggling to find spare part, what do you think? I see that you have experience in opening this little puppies :-)
Thanks and keep a good work
Remember the PCB detects postion signal. Even if the motor is ok the main pcb may be an issue. From my experience, the motor is usually faulty. I would make mention that units installed in coastal regions are subject to salt air degradation and this can also add to main pcb failures
Hi, thanks for your reply. I just find out that is impossible to repair electronics in this kind motor that i have because electronic components are submerged into plastic.
I just find this useful document www.scribd.com/doc/61345930/2-dc-Motor-Checking-Procedure and build 3 separate power supply, one for dc 310, one for 15V DC and one with voltage regulation from 1-6V. I have tried to start up motor but it does not start. It is definitely a motor failure! Only difference is when I unplug 6v dc command voltage I can rotate motor with hand freely but with command voltage there is some resistance to turn with hand on one side, but no independent movement at all.
Can I replace original motor with some substitute with same dimensions and voltage? My motor is ICF-340-30-4, what number 4 is for, I understand 340 is 340V for red wire and motor power of 30W but number 4 is mystery. My worry is that pulses per one rotation are different for different motors but maybe lot of motors use some standard for example 2 pulses per one rotor turn, I do no know. Probably depends how much hall effect sensors are in motor.
They are not serviceable , there are usually no spare parts other than a full replacement motor. The one I have opened was for view here , it could not be re-assembled again. The manufacturer of your brand of air-conditioner should have the spare part listed, I would contact them first.
Thanks Dennis i will try to get original part if not experimenting with other types is my goal, maybe this : www.buychinabulk.com/goods/item/detail/id/534039729889 or this: www.yoycart.com/Product/13033980403/ etc
This is mine: ibb.co/k1j0aF
Bye
@@klokoloko2114 I am trying to run a similar mini-split motor continuously on high power without a PCB controller so how could I build/buy a 325V DC power supply. I think the 15v and variable 3-6v power supply are common online.