I have an old HVAC blower motor which was removed from a Carrier air handler on grounds it was defective. It's half horsepower, with ECM 3.0 controls. It has an AC input for motor power and a four pin control connector marked common, Rx, Tx and V+. Physically it's in perfect shape. On the bench it seems to work fine. The test procedure applies 24 VAC between common and Rx, the motor soft starts and runs smoothly. I'd like to adapt the motor to other uses and if possible exploit the variable speed feature, but there's no info readily available that describes the control signals. There's a YouTube video at https://www.youtube.com/watch?v=Zaj_a68lry8 showing a physical teardown implying a digital interface is used, but no electrical testing is shown. Does anybody have further information that might be used to communicate with the controller? Thanks for reading, bob prohaska
ECM 3.0 motor speed controls
Started by ●December 28, 2023
Reply by ●December 28, 20232023-12-28
On Thursday, December 28, 2023 at 11:09:28 AM UTC-5, bob prohaska wrote:> I have an old HVAC blower motor which was removed from > a Carrier air handler on grounds it was defective. It's > half horsepower, with ECM 3.0 controls. It has an AC > input for motor power and a four pin control connector > marked common, Rx, Tx and V+. Physically it's in perfect > shape. > > On the bench it seems to work fine. The test procedure > applies 24 VAC between common and Rx, the motor soft > starts and runs smoothly. > > I'd like to adapt the motor to other uses and if possible > exploit the variable speed feature, but there's no info > readily available that describes the control signals. > > There's a YouTube video at > https://www.youtube.com/watch?v=Zaj_a68lry8 > showing a physical teardown implying a digital > interface is used, but no electrical testing is > shown. > > Does anybody have further information that might be > used to communicate with the controller?Genteq makes the TecMatePro universal ECM tester. Amazon sells it for 145$, but there are alternatives for less like SUPCO and Mars, both excellent manufacturers. There are some U-TooB videos on rolling your own ECM tester too. The idea of the TecMatePro tester is to be able to test the motor and its controller out-of-system. In system testing can be problematic. Hackaday has a service guide: https://cdn.hackaday.io/files/1668027136456768/ECM%20Service%20Guide.pdf 50-50 chance the motor/ controller is defective.> > Thanks for reading, > > bob prohaska
Reply by ●December 30, 20232023-12-30
In article <umk6jh$eaiu$1@dont-email.me>, bob prohaska <bp@www.zefox.net> wrote:>I have an old HVAC blower motor which was removed from >a Carrier air handler on grounds it was defective. It's >half horsepower, with ECM 3.0 controls. It has an AC >input for motor power and a four pin control connector >marked common, Rx, Tx and V+. Physically it's in perfect >shape. > >On the bench it seems to work fine. The test procedure >applies 24 VAC between common and Rx, the motor soft >starts and runs smoothly. > >I'd like to adapt the motor to other uses and if possible >exploit the variable speed feature, but there's no info >readily available that describes the control signals. > >There's a YouTube video at >https://www.youtube.com/watch?v=Zaj_a68lry8 >showing a physical teardown implying a digital >interface is used, but no electrical testing is >shown. > >Does anybody have further information that might be >used to communicate with the controller? >If you have access to a working version of that motor attach a scope to Rx and Tx. At least I managed to find out how to control a blower to mix gas and air with my central heating.>Thanks for reading, > >bob prohaska-- Don't praise the day before the evening. One swallow doesn't make spring. You must not say "hey" before you have crossed the bridge. Don't sell the hide of the bear until you shot it. Better one bird in the hand than ten in the air. First gain is a cat spinning. - the Wise from Antrim -
Reply by ●December 31, 20232023-12-31
albert <albert@cherry.(none)> wrote:> In article <umk6jh$eaiu$1@dont-email.me>, > bob prohaska <bp@www.zefox.net> wrote: >>I have an old HVAC blower motor which was removed from >>a Carrier air handler on grounds it was defective. It's >>half horsepower, with ECM 3.0 controls. It has an AC >>input for motor power and a four pin control connector >>marked common, Rx, Tx and V+. Physically it's in perfect >>shape. >> >>On the bench it seems to work fine. The test procedure >>applies 24 VAC between common and Rx, the motor soft >>starts and runs smoothly. >> >>I'd like to adapt the motor to other uses and if possible >>exploit the variable speed feature, but there's no info >>readily available that describes the control signals. >> >>There's a YouTube video at >>https://www.youtube.com/watch?v=Zaj_a68lry8 >>showing a physical teardown implying a digital >>interface is used, but no electrical testing is >>shown. >> >>Does anybody have further information that might be >>used to communicate with the controller? >> > > If you have access to a working version of that motor > attach a scope to Rx and Tx. At least I managed to > find out how to control a blower to mix gas and air > with my central heating.The test I used consisted of merely applying 24 volts AC between Rx and Common. How that can work via a digital input eludes me. I don't have a scope. Can you describe what you did to control your motor? I gather certain "smart" motors have dual-use inputs. While I have the running motor I do not have access to the equipment it came from so It's impossible to see what signals were in use. Thanks for writing! bob prohaska
Reply by ●January 2, 20242024-01-02
In article <umsdn0$1qlm1$1@dont-email.me>, bob prohaska <bp@www.zefox.net> wrote:>albert <albert@cherry.(none)> wrote: >> In article <umk6jh$eaiu$1@dont-email.me>, >> bob prohaska <bp@www.zefox.net> wrote: >>>I have an old HVAC blower motor which was removed from >>>a Carrier air handler on grounds it was defective. It's >>>half horsepower, with ECM 3.0 controls. It has an AC >>>input for motor power and a four pin control connector >>>marked common, Rx, Tx and V+. Physically it's in perfect >>>shape. >>> >>>On the bench it seems to work fine. The test procedure >>>applies 24 VAC between common and Rx, the motor soft >>>starts and runs smoothly. >>> >>>I'd like to adapt the motor to other uses and if possible >>>exploit the variable speed feature, but there's no info >>>readily available that describes the control signals. >>> >>>There's a YouTube video at >>>https://www.youtube.com/watch?v=Zaj_a68lry8 >>>showing a physical teardown implying a digital >>>interface is used, but no electrical testing is >>>shown. >>> >>>Does anybody have further information that might be >>>used to communicate with the controller? >>> >> >> If you have access to a working version of that motor >> attach a scope to Rx and Tx. At least I managed to >> find out how to control a blower to mix gas and air >> with my central heating. > >The test I used consisted of merely applying 24 volts AC >between Rx and Common. How that can work via a digital >input eludes me. > >I don't have a scope. Can you describe what you did >to control your motor? I gather certain "smart" motors >have dual-use inputs. While I have the running motor >I do not have access to the equipment it came from so >It's impossible to see what signals were in use.The blower was working in the central heating system. The power pins were just 0 and 24 V, permanently. It took some effort to attach a thin wire to the control pin. Then is become obvious that it was a pwm signal of 2 Khz, with the width controlling the speed of the blower.> >Thanks for writing! > >bob prohaska >-- Don't praise the day before the evening. One swallow doesn't make spring. You must not say "hey" before you have crossed the bridge. Don't sell the hide of the bear until you shot it. Better one bird in the hand than ten in the air. First gain is a cat spinning. - the Wise from Antrim -
Reply by ●January 4, 20242024-01-04
albert <albert@cherry.(none)> wrote:> In article <umsdn0$1qlm1$1@dont-email.me>, > bob prohaska <bp@www.zefox.net> wrote: >>albert <albert@cherry.(none)> wrote: >>> In article <umk6jh$eaiu$1@dont-email.me>, >>> bob prohaska <bp@www.zefox.net> wrote: >>>>I have an old HVAC blower motor which was removed from >>>>a Carrier air handler on grounds it was defective. It's >>>>half horsepower, with ECM 3.0 controls. It has an AC >>>>input for motor power and a four pin control connector >>>>marked common, Rx, Tx and V+. Physically it's in perfect >>>>shape. >>>> >>>>On the bench it seems to work fine. The test procedure >>>>applies 24 VAC between common and Rx, the motor soft >>>>starts and runs smoothly. >>>> >>>>I'd like to adapt the motor to other uses and if possible >>>>exploit the variable speed feature, but there's no info >>>>readily available that describes the control signals. >>>> >>>>There's a YouTube video at >>>>https://www.youtube.com/watch?v=Zaj_a68lry8 >>>>showing a physical teardown implying a digital >>>>interface is used, but no electrical testing is >>>>shown. >>>> >>>>Does anybody have further information that might be >>>>used to communicate with the controller? >>>> >>> >>> If you have access to a working version of that motor >>> attach a scope to Rx and Tx. At least I managed to >>> find out how to control a blower to mix gas and air >>> with my central heating. >> >>The test I used consisted of merely applying 24 volts AC >>between Rx and Common. How that can work via a digital >>input eludes me. >> >>I don't have a scope. Can you describe what you did >>to control your motor? I gather certain "smart" motors >>have dual-use inputs. While I have the running motor >>I do not have access to the equipment it came from so >>It's impossible to see what signals were in use. > > The blower was working in the central heating system. > The power pins were just 0 and 24 V, permanently. > It took some effort to attach a thin wire to the control pin. > Then is become obvious that it was a pwm signal of 2 Khz, > with the width controlling the speed of the blower.Motors marked X13 are known to take PWM inputs. Mine is marked ECM 3.0, how was yours marked? Thanks for writing! bob prohaska
