Roadster motor - is it really ultra reliable ?

[PV4EV]

Does anyone have any record of a Roadster motor being replaced or failing ?


From what I can tell, the motor appears to be amazingly bullet proof. As we've seen this past week the ESS 'brick' incident was more about neglect than any genuine fault. Even so, this makes it a 1 in 2,500 failure, or 5 in 2,500 if you believe the unsubstantiated claims by the original blogger, but I still think this is a very low percentage compared to major problems with more conventional ICE 'sports' cars.

 

[Doug_G]

What's to go wrong? It has one rotor with a bearing at each end.

 

[Mycroft]

Yeah, it's more likely that the electronics or battery pack will go wonky. Hopefully the bad ones are weeded out by the time the extended warranty expires.

 

[PV4EV]

What's to go wrong? It has one rotor with a bearing at each end.

Agreed !

It would appear to be ultra reliable, as it should be.

Being able to state that the Tesla motor has proved to be 100% reliable is an interesting factoid for throwing back at EV deniers most of whom still drive cars powered by a highly inefficient mechanical assembly full of conrods thrashing about in oil, that go 'bang' far more often than an induction motor.

 

[ElSupreme]

In my industrial experience the only thing that really goes wrong with induction motors is the windings melt. And that is exceptionally rare, and caused by improper cooling, or entirely too much current. But the Tesla is water cooled, and has a highly advanced inverter providing power, so those winding are well taken care of.

I would think in an automotive duty application the bearings may not last as long as a typical fixed industrial setting (baring harsh chemicals). But they have very small forces on them, and can be made quite large/durable so I doubt they would fail in the lifetime of a car (unless there is particle ingress).

 

[vfx]

I know of two motor replacements. Have no idea what kind of sample that is. WOuld think the the Model S motor would address any issues found in those.

 

[hcsharp]

Any details Eric?
I've heard that the insulation on the wires/windings can break down in an induction motor, resulting ultimately in failure. Overheating is a big contributor but of course the PEM reduces power long before it gets too hot. The Roadster motor is air cooled and the new fans don't let it get very warm. Vibration might also wear out the insulation with time. One of the engineers told me that the motor was designed to last 500,000 miles. A sales person in the Denver store told me 1,000,000 miles for the motor and 500,000 for the tranny.

 

[Bearman]

Ive toasted several electical motors, always by overheating them

 

[PV4EV]

Any details Eric?
I've heard that the insulation on the wires/windings can break down in an induction motor, resulting ultimately in failure. Overheating is a big contributor but of course the PEM reduces power long before it gets too hot. The Roadster motor is air cooled and the new fans don't let it get very warm. Vibration might also wear out the insulation with time. One of the engineers told me that the motor was designed to last 500,000 miles. A sales person in the Denver store told me 1,000,000 miles for the motor and 500,000 for the tranny.

Besides cursory checks at service intervals, I was once told by a Tesla person that the bearings might need a check at 750,000 miles ... tell that to a Ferrari owner and he'll laugh in your general direction :biggrin:

Whatever it actually is, most people subconsciously accept that the electric motors in their refrigerator, AC compressors, fans, PCs, etc, work tirelessly for a 'very long time' without ever thinking they need any servicing. Its a good point for selling people on the idea EV's.

 

[vfx]

No details. One was on a 1.5, the other unknown. Cooling improved after VIN 500.

On store visits I occasionally see shiny motors not in cars. One would presume that they are not there for paperweights.

 

[dwegmull]

In my industrial experience the only thing that really goes wrong with induction motors is the windings melt. And that is exceptionally rare, and caused by improper cooling, or entirely too much current. But the Tesla is water cooled, and has a highly advanced inverter providing power, so those winding are well taken care of.

I would think in an automotive duty application the bearings may not last as long as a typical fixed industrial setting (baring harsh chemicals). But they have very small forces on them, and can be made quite large/durable so I doubt they would fail in the lifetime of a car (unless there is particle ingress).

My understanding is that the battery is liquid cooled whereas the electronics and motor are air cooled.

 

[ElSupreme]

My understanding is that the battery is liquid cooled whereas the electronics and motor are air cooled.

You are correct. I was thinking Model S.

And when I say windings melt I really mean the coating on the windings, causing a short.

Industrial induction motors generally have a fan attached to the drive shaft to cool. And if you run them slower than their rated speed (i.e. with a VFD) they get insufficient cooling and can melt. The roadster motor is cooled by an external fan so variable speed is not an issue. The other failure mode is too much current which causes too much resistive heat in the windings and they melt their coating and short.

 

[jaanton]

Besides cursory checks at service intervals, I was once told by a Tesla person that the bearings might need a check at 750,000 miles ... tell that to a Ferrari owner and he'll laugh in your general direction :biggrin:

That reminds me... I bought my house from a guy who was a machinist and inspection found the furnace motor bearing was worn to bad. I asked the seller to fix the problem and he machined a new bearing. Seems like not a big deal, except he worked on stuff for LBL so he machined a Teflon coated super hard replacement which was very nice. Replaced the furnace eventually due to asbestos removal, but I wish I'd have kept that motor. I wonder how long it would last.

 

[brianman]

On store visits I occasionally see shiny motors not in cars. One would presume that they are not there for paperweights.

While I agree, you've distracted me...

Tesla skateboard paperweight would be an excellent Father's Day gift idea. I wonder if Tesla merchandising is anywhere near thinking about such things. It would really take the edge off waiting for the July+ deliveries.

 

[widodh]

I know one motor which was replaced in a Roadster Sport 2.0, not sure why though.

I think the Roadster motor is vulnerable due to the air-cooling, but the liquid-cooled motor of the S should be much more reliable I think.

 

[W.Petefish]

Does anyone have any record of a Roadster motor being replaced or failing ?


From what I can tell, the motor appears to be amazingly bullet proof. As we've seen this past week the ESS 'brick' incident was more about neglect than any genuine fault. Even so, this makes it a 1 in 2,500 failure, or 5 in 2,500 if you believe the unsubstantiated claims by the original blogger, but I still think this is a very low percentage compared to major problems with more conventional ICE 'sports' cars.

I heard through a friend, a PEM went bad because of someone living on a dirt/gravel road. The PEM was clogged full of dirt. I suspect that the motor wasn't that much farther from overheat failure.

 

[bolosky]

I heard through a friend, a PEM went bad because of someone living on a dirt/gravel road. The PEM was clogged full of dirt. I suspect that the motor wasn't that much farther from overheat failure.

I had a PEM failure pretty early on with my 2.0. The Rangers said that it was a power supply inside the PEM, which I found kind of funny since the PEM *is* a power supply. Anyway, they came and replaced it in the garage where the car died and I haven't had a problem since. So mine was clearly a manufacturing defect rather than wearing out.

 

[frequencydip]

Its not very hard to overheat the motor in a 1.5, just drive the car hard for abut 5 min and it overheats. This seams to have been fixed in the 2.0 as they increased airflow over the motor.

 

[Doug_G]

The new & improved fans seemed to have helped even more. I haven't had a chance to try and really stress the drivetrain yet, but it cools down pretty quickly when the fan kicks in.