What are we going to do about the new ECM motors that are going o?

[ChaseAir]

Just had another one today. 2 yr old york air handler, bad ECM motor. Is there any adequate drop in solution? This one was a 1/3 hp non programmable. pretty much everyone we install has an ecm, and we guarantee 24 hour repair within 2 yrs of install.

[Rcb2875]

These motors or at least the modules seem to be sensitive to 'dirty power'. We are starting to put voltage protection on every install. For a few bucks it's worth a shot since fluctuating power seems to be what is killing them.

[mark beiser]

In addition to the potential power issues, they don't like high static pressures.

One or the other seems to be the common theme with most ECM motor failures.

Feed them clean power and reasonable static pressures and they are extremely reliable.

[BaldLoonie]

For cooling or an air handler, probably could put a PSC in temporarily. Some furnaces too. Others "talk" to the motor and if it reports an error, the furnace won't fire.

[beenthere]

Sounds like it was an X13. Might want to carry some in stock.

[Special Ed]

Interesting....

Which mfg is it? GE or Emerson? Seems I have more issues w/the GE. I've got two that have gone bad in the last week.

[mark beiser]

I still haven't run across a bad X13 motor.

I want to crack one open and see if it has the same/similar thermistor that the ECM2.x motors have.

[ferd1942]

I noted the comment about static pressure.

It's not uncommon for me to see 0.7" or 0.8" with a furnace. Is that a problem for ECM motors? I know Trane furnace product data goes to 0.9". If the SP's within the range published in the Product Data, should I be concerned? Or should I only be concerned when it's beyond the published range (IE: 1.0" or more for the Trane)?

Many thanks.

[beenthere]

When it gets close. Remember when you put that new furnace in with a new air filter. it will only be a few weeks before the filter starts to load up and increase static pressure. So if the furnace list .9", and your starting with a .8". It won't be long before your over the rating.

[jimj]

I noted the comment about static pressure.

It's not uncommon for me to see 0.7" or 0.8" with a furnace. Is that a problem for ECM motors? I know Trane furnace product data goes to 0.9". If the SP's within the range published in the Product Data, should I be concerned? Or should I only be concerned when it's beyond the published range (IE: 1.0" or more for the Trane)?

Many thanks.

This may help.

[ferd1942]

Thank you so much for posting that! I'd heard from our Carrier distributor about the motors hunting at high SP's, with premature failures occurring. I've downloaded the document for future reference. And it was nice to see GE essentially confirm that a good duct design will save energy every time a system runs.

I've done some math indicating high SP loses a SEER point or so due to increased blower power: The customer paid for a 16, but received a 15 or less because of the poor ductwork, high SP and increased blower power; when I see that, I call it "Bait and Switch".

[gourdhead]

Double check your installation manuals, most Yorks are rated at .5" ESP.

[rheemtrane789]

yeap i went and purchased a v-27 zebra and a zebra stat even not needed to check system operation on a ecm motor this lil thing helps but i live in miami were high hum is always an issue so i always deal with ecm motors and almost always its the elec module cuaseing the issue im a new member figured i throw my opinion

[rheemtrane789]

also ecm tech is here to stay i love them there so easy to check plus i believe moisture is a primary cuase air passing thru the motor on a unit iss about 48 to 59 degrees constant on a lil circuit board attached to the motor i beileve in tiime this constant moisture build up over time will cuase the electronicspackage give out

[steve3871m]

I've done some math indicating high SP loses a SEER point or so due to increased blower power:

Please share this with us. I would like to see your numbers.

[ferd1942]

All furnace nameplates are marked 0.5" ESP. That's an AGA certification, never learned what that's about. I believe it dates back to when people designed duct systems at 0.5", to include the coil: 0.5" furnace less 0.25" for the coil left 0.25" for ducts, duct fittings, registers, grilles and exotic air cleaners. Today, it's quite common for national builders and others to select coils at 0.4", so the 0.5" marking must be ignored.

That 0.5" marking is not to be confused with the manufacturer's product data. York, for instance, permits its TM9V furnaces to be operated at 1.0".

[ferd1942]

I'm away, don't have the info with me. Here's the gist.

SEER is BTU/W-H (BTU per watt-hour). On that basis, you'd expect a 16 SEER 2 ton unit to have a 1,500 watt power input (24,000/16 = 1,500). That includes blower power input at some (0.5"??? - be interested to hear from someone about that) SP. Operating an ECM at a higher SP (as in poor coil selection, 0.10" duct design, etc.) increases blower power input.

Add 100 W of blower power and the 16 becomes a 15 (24,000/1,600 = 15).

[steve3871m]

All furnace nameplates are marked 0.5" ESP. That's an AGA certification, never learned what that's about. I believe it dates back to when people designed duct systems at 0.5", to include the coil: 0.5" furnace less 0.25" for the coil left 0.25" for ducts, duct fittings, registers, grilles and exotic air cleaners. Today, it's quite common for national builders and others to select coils at 0.4", so the 0.5" marking must be ignored.

That 0.5" marking is not to be confused with the manufacturer's product data. York, for instance, permits its TM9V furnaces to be operated at 1.0".

The Maximum rated ESP is usually .5 for a cooling ready unit and .2 for heat only.
Most mobile home units such as Intertherm and Coleman that are approved for that application max out at .3".
You can purchase a high static RTU @ 1.0" and many York RTU's @ 5 and 5 6.5 tons are rated to .7"
The certification is basically stating that at the "X" amount of static pressure or below this rating the equipment will operate as it is supposed to.

Anything above this rating there may be performance concerns.

This does not mean that you can't design a system @ .6"wc (thats rated .5) if @ .6" it delivers the rated cfm you need as outlined on the fan curve chart.

[steve3871m]

I'm away, don't have the info with me. Here's the gist.

SEER is BTU/W-H (BTU per watt-hour). On that basis, you'd expect a 16 SEER 2 ton unit to have a 1,500 watt power input (24,000/16 = 1,500). That includes blower power input at some (0.5"??? - be interested to hear from someone about that) SP. Operating an ECM at a higher SP (as in poor coil selection, 0.10" duct design, etc.) increases blower power input.

Add 100 W of blower power and the 16 becomes a 15 (24,000/1,600 = 15).

Actually, BTU/W_H is EER, not to be confused with SEER. EER is "at that instant" where as SEER is "Seasonal" and not easily computed.
SEER is defined by AHRI and has a standard (ARI 210/240) and is not easily calculated.
This is why I asked as how you felt you can determine a gain or loss of a point on your own. You would need to know the amount of cooling days, operating cost of the air handler and other factors to compute the SEER.

[Nytefog]

i thought that the module failure in the older model GE modules was due to high static pressure and the lack of limiting the motors rpms like the new modules do at 1400 rpms max. We had alot of capacitor failures in the modules from poor duct systems that had high static pressure. The issue had been rectified by the 1400 rpm limit on the new modules. Now duct repairs are needed to drop down the static pressure.

I've seen very high static pressure systems that have ECM motors cause the blower wheel to deform to an egg shape due to the high motor speed and high static pressure! CRAZY!!