Understanding ECM Motors

[@davidkish1251]

Excellent Instructor, clear and deliberate

[@jimrasa9705]

Thank You! This is the best explanation of an ECM that I was able to understand! 🙂

[@jkbrown5496]

The problem is while ECM technology is excellent, the high amperage at high static pressures burns out the controls. This is not a concern to the mfrs as they please the government with an efficiency test on a pristine design system, and as the motors are mfr/system specific the mfrs can charge near 30% of the cost of original system for the replacement motor. All “savings” used to sell high SEER to customers is then reclaimed by the mfrs with all the heat going onto the HVAC contractor/tech. As everything is in the control microprocessor, they could program the motors to not go up so high in amp draw and save the motor, but then they’d lose out on the lucrative parts profits from being the sole source supplier of properly characterized modules. Also, the customer gets a long period of no HVAC while the part is being shipped in.

[@joesprauve2408]

Happening to me as I type this been out of AC four five days now as I wait for an new ECM smh

[@realSamAndrew]

@@joesprauve2408 you should just replace it with a new PSC motor and call it a day. Then in the future, you have a much easier repair if needed again.

[@Ric_James]

This video is great and needs more comments!

[@ZebraHVAC]

We're glad you enjoy the Video! Thanks for commenting!

[@alexzapata692]

Great presentation. Very informative.

[@tripplewhipper]

Thanks for the video, very informative

[@GotchaplumberGotchahvac]

Good information.

[@mikefixac]

Thanks for the video. Well done for sure. Went to look for Part II, but was unsuccessful.

[@hectorlongoria9625]

I have x13 electronic air handler after it does its cycle fan turns back on for a second turns of it does it 3 to 10 times at a time icm both have been replaced also fan motor but still does the same thing any information

[@brianlittle717]

AC to DC to 3 phase AC? What’s the purpose of the DC?

[@mackenziegray2090]

DC voltage is more powerful than AC. But we use AC at our house because it can travel much farther distance. You can use a cordless drill, say a 12volt battery and do the same work compared to a 120v corded drill. It's just more energy efficient.

[@mackenziegray2090]

The 3 phase Ac really is just artificial AC voltage. It just pulsating that dc voltage at the motors poles and creating that AC sine wave you would see on an oscilloscope.

[@brianlittle717]

@@mackenziegray2090 work and power have nothing to do with AC or DC. Work is the product of force and distance. Power is the rate of doing work. It’s more to do with the horsepower as to how much power a motor has and less to do with the source of energy.

[@brianlittle717]

@@mackenziegray2090 why not just run it on AC to begin with? Is the benefit in going from single to three phase?

[@mackenziegray2090]

@@brianlittle717 I was just using the word power or work to describe you can do more with dc than ac. Ecm motors really don't pull that much amps compared to psc motors. Especially if you let the capacitor degrade over time they'll pull even more amps because the motor isn't spinning fast enough to create back EMF or its own resistance with inductive reactance.

[@CCCC-tq8yo]

Goooooo Stan

[@brianlittle717]

I don’t understand what’s meant by 3 phase in DC current. There’s no such thing as 3 phase in DC.

[@brianlittle717]

@@donalddebat57 I gotcha. An artificial 3 phase sine wave then. But that would be an AC sine wave none the less. Not a direct current.

[@waltersmith7950]

@@brianlittle717 The DC is used just like an inverter which produces pure sine wave voltage. In this case it produces 3 phase variable voltage and frequency. Don't know what the output would look like on a scope. Even more complicated is that only 2 phases (120 degrees apart) are powered at any given time (sequentially) thus causing the magnetic rotor to turn and the unpowered phase receives EMF generated by the rotor which is used as a feedback to determine commutation, direction and speed. I don't know if the power sent to the 2 phases is in the form of a +/- sine wave or a +/- pulse. The whole idea is fascinating and it definitely works. I have a 19 yr old 2 stage gas heating & cooling (dual compressor & txv on evaporator) system with variable speed & ramping on the blower, condenser fan and inducer. The biggest advantage is humidity control in summer by varying CFM. When heating, even the inducer speed is lowered shortly after the cycle starts which possibly allows hotter air to be circulated(?). The condenser fan seems to run either high or low as per which pump is running (and switching to the larger pump only happens on a super hot day). Since installed, the larger pump probably only has 20 hrs run time. If I had it to do over again ($), for cooling I would go with a single compressor, txv on evaporator and definitely variable & ramping blower. I hope my rambling helps in some small way. 😄

[@brianlittle717]

@@waltersmith7950 like I said. The inverter is creating alternating current. Refrigerators have been using variable drive. The advantage is there is no temperature swing between the on and off cycles. The disadvantage with refrigerators anyway, is that they compressors only last a couple years.

[@waltersmith7950]

@@brianlittle717 OK.

[@brianlittle717]

@@pauledwards3325 almost. A rectifier circuit needs a lot of filtering to simulate a true direct current, but it is part of a power supply. If you start with a single phase AC power source and use a power supply to produce a direct current, then you simply have a direct current. The term 3 phase relates to the three wires and the three transformers on the power pole, where voltage sine waves are 120* apart from one wire to the next. In DC, there are no sine waves, but depending how well it’s filtered, there could be harmonics. There actually is such a thing as a 3 phase rectifier but it is for high power industrial applications, must have 3 phase service from the power company, and they are extremely rare in the last 50 years or so. The 3 phase rectifier reduced the effect of harmonics, but transistor circuits have solved that problem anyway.