Maybe the static pressure is way higher than what the manufacturer recommends, due to undersized ductwork, or oversized equipment or both? You know like trying to push ten pounds of sand in a tube made to handle five lbs.

Anybody can be a parts changer, need to find the root cause, what did the Tech. say why the motor failed, as you may be repeating this scenario again down the road?

 

THIS! ^^^

Check the short video in my signature, send it to your sister.

 

Poor/incorrect Air flow and dirty filters kill blower motors

 

I'll have to ask her if she's closing off registers because I'd assume the installers sized it correctly. I'm pretty sure the maintenance contract she has includes filter changes, but I'll have to ask her.
It was a replacement system 4 years ago so they may have just sized it based on what was originally there but I'm sure they did some basic analysis to verify the size. The full model number is FZ4ANP048L00EAA (I assume that's 4 ton). She told me the motor they ordered is 3/4 HP.

 

I'll have to ask her if she's closing off registers because I'd assume the installers sized it correctly. I'm pretty sure the maintenance contract she has includes filter changes, but I'll have to ask her.
It was a replacement system 4 years ago so they may have just sized it based on what was originally there but I'm sure they did some basic analysis to verify the size. The full model number is FZ4ANP048L00EAA (I assume that's 4 ton). She told me the motor they ordered is 3/4 HP.

Really? My first assumption is it went to the lowest bidder.

 

I checked with her and she said she didn't close any registers, but her service contract only replaces filters every 6 months (they are the 5" size but I forgot to ask about the MERV).

 

It could be bad install with excessive static pressure. Or it could just be a crap motor. I've seen a lot of premature failures with the Broad Ocean motors Carrier has used in some of their air handler models the past few years.

 

That's useful info to me. It's like when a car part fails and you search online to find hundreds of people with the same make and model car had the same part failure. Often the car company issues a service bulletin to their dealers.

 

Many can get a year out of 5" medias. But if it gets dirty and otherwise the system is starved for air, that can be a problem

Probably just one of those things, sad to say.

 

She had any storms or power surges lately? even if it's the perfect install "I've never seen one of those" but I do believe in miracles :grin2: All ECM's hate these conditions, and are prone to fail.

 

She's in Delray Beach so lightning is common problem.

 

If they don't break they can't sell new ones. FWIW it was supposed to wait till just after warranty to break. Some of them get impatient. The blower motor in my air handler is 40 years old. I thought that it would quit one day and I'd replace it with an X13 blower motor. I've had the X13 sitting on a shelf for 15 years now. These guys, some of them, are codependent, and tend to make up excuses for the manufacturer/s poor designs. While this or that may shorten the life of the motor, if it was worth anything to begin with, we wouldn't be having this conversation.

That being said, I think it's mainly the fact that they are pulling cold air over them and don't generate as much heat as their predecessors. The bearings begin to fail prematurely due to condensation on the motor on the off cycle. Is the shaft rusty? If not, then may have been a power surge. I read once that the GE motors are designed to limit power consumption under high static conditions to prevent overheating, so I don't think high static per se is a problem. Low air flow OTOH due to the high static will cause a colder coil and more condensation on and in the motor.

 

The ECMs limit themselves to a certain extent, but not enough to prevent a shortening of life due to stress on the electronic components, when operating at the high end of their designed range. That said, this failure is much more of an issue with the constant airflow variable speed ECMS, than the constant torque X13 type.

I find problems with ECM electronics/module much more often than mechanical problems/bearings.

A warning about that old X13 in the box - the early X13s were susceptible to moisture ruining the electronics - so they only held up when installed on a blow-through configuration (before the coil). Put it on a draw through air handler or package unit and it will likely last a couple years, tops. The design of the X13 has improved dramatically in the past 15 years.

 

Here's a link you can watch for basic understanding of Airflow

https://youtu.be/45gX7Jb60JM

Sent from my SM-G998U using Tapatalk

 

This is from RegalRexnord.

Regarding Constant cfm ECM motors.
"If the TESP becomes extreme (higher than the maximum recommended by the HVAC system manufacturer), airflow may decrease, and the system may suffer failures related to low airflow. [notice no mention of failure due to motor stress here, but rather due to low airflow, and then they go on to state..]There is a speed limit built into most ECMs. This limit is programmed by the HVAC system manufacturer into the motor control. Keeping in mind that the rpm will increase with TESP, the speed limit is an overtemperature protection control that limits motor torque (current) at the speed limit."

"A comparison of power consumption shows that the constant torque ECM (X13) also uses more power as the TESP increases (in order to maintain motor torque), whereas the induction motor uses less power. However, as stated earlier, due to its electrical efficiency, the (X13) ECM uses less total power than the PSC, even at higher TESP values."

And York, that I quoted in the previous reply, states that the X13 failures are almost exclusively on draw thru applications such as air handlers and package units, and they make the same connection that I did, that it must be the moisture. Above, Regal doesn't state it, but it isn't difficult to connect the dots. Why would they admit to a design flaw? Corporations are about the dollar, and don't in general do things "just 'cause it's the right thing to do". If a class action isn't brought, then plan on a continuous stream of products literally designed to fail just out of warranty.

source: https://www.regalrexnord.com/brands...termarket-Products/Evergreen-Motors/ec-indoor-blower-motors-airflow-performance

And btw, even if the electronics are all sealed, the motor itself and the bearings are not. Bearings in these fail just like they do in other motors, and will fail sooner if they stay wet.

These are just my opinions, except the parts that are quoted of course. Any other opinions are more than welcome.

 

Here is a bulletin from Regal claiming that operation at higher speeds shortens the life of the capacitors on the motor module, compared to running at lower speeds: https://www.regalrexnord.com/-/medi...apacitor-Life-Analysis-11_02_10.pdf?la=en&hash=E6EC070BE334671558CC8E7F58EB62BC

It would be nice if they held up better in high static, but most products have a shorter life in harsh conditions so I'm not going to get super mad about it. And it's not like a PSC motor installed in a high static application was without issue - it's just that the problems came on the refrigeration/heat exchanger side due to low airflow, rather than the motor side. Personally I would rather have to change a motor module every couple years, rather than a compressor or heat exchanger, so I'd argue the ECM was still an improvement...

Anyhow I'm not going to attack the durability of ECMs overall because I've seen them run for literal decades without issue, though I agree that over the years some released crappy designs that don't hold up even when installed properly. You are correct that the older X13s had huge problems with early failure on draw through applications due to moisture, like I said. That was a completely separate issue. I'm certainly not trying to defend crappy products, and my first post in this thread pointed out I've had issues with the brand of motor Carrier uses even without high static.

 

Fair enough. Interesting to note that the ability to maintain higher cfm at high static is the main selling point of these things.

 

Just looked at that bulletin. Yes, capacitor life is a function of voltage and temperature. But which capacitor temperature will be higher, the one on a motor of a blow thru coil, or on the motor of a draw thru, assuming the same blower TSP? Hmmm.

Whether they improved sealing or not, we still see the majority of warranty replacements (under 10 years old) on draw thru systems. I replaced exactly 2 modules, and in both instances the problem turned out to be bearings. After that I only replaced the entire motor. Warranty covered it so why not? In one of those instances fire shot out of the brand new module that was right in front of my face. Fool me once. Thing about blower bearings is, sometimes you have to remove the wheel to test them.

But the real kicker here is that Regal is attempting to pass the buck. It isn't them, no, it's China, it's China's fault that the motors are failing! Damn crappy capacitors! Yeah. Same story on dual capacitors, that once upon a time lasted 50 years. But who chooses which capacitors to install in their products? And how hard would it be to make the capacitors replaceable?

 

Update: The system is working with the new motor.
I said earlier that they ordered a 3/4 HP motor but said that carrier sent them a 1/2 HP motor. I know mistakes happen but with all the details on the labels manufacturers use, it seems carrier would have known which motor to send. They then told her they attempted to get the correct motor from carrier but instead got an aftermarket motor (they say is OEM) from Totaline. If the correct motor was delivered initially, it would have taken only 2 days to get the system back up and running. Instead, it took 8 days since the initial failure, which I assume is a long time to be without AC in south Florida.

Any thoughts on Totaline aftermarket motors? Do they really sell OEM parts? Seems possible since there probably aren't more than a few motor manufacturers. I looked up the Carrier part number and it seems to be HD46AR278 but I wasn't able to find that on the totaline website by model number. If I just search for a 3/4 hp ECM motor at 115v, I get this: P257-FLEX1371. So, if they did give her a Totaline motor, that's probably the one she has.

 

Any thoughts on Totaline aftermarket motors? Do they really sell OEM parts.

Thought Carrier owned Totalline for many many decades.

 

If that's the case, it's probably OEM. I'm not sure why the guy told her it was an aftermarket replacement. Maybe it's a big HVAC company and the tech doesn't get involved in the part ordering process so he's just telling my sister what the parts people told him. It's working now and she seems happy with it. Let's see if it makes it past 4 years.

 

Friend of mine owns 2 rental houses , on the same block , just a few houses apart

6 years later one of the indoor ECM motors failed

Whoever installed units forgot to Register them , so it drops to 5 year warranty in that case

Had to buy it regardless

1 week later his other units blower motor failed ..... wow how ironic