[dracula]

VFD and motor bearing failure is not new

opps

 

[bcgnet]

trane uses ceramic bearings and brush kits on their vfd centrifugals

 

[stickerhead]

We'll according to brand "Y", brand "T" has problems due to the carrier frequency. That's why brand "Y" has less bearing failures. Not sure if this is completely true but I hear more complaints about brand "T" VSD chillers.

 

[John Culpepper]

VFD Problems

I'm glad to get this kind of information here. I'm going to get 2 vfds replaced in a couple of weeks. The old ones are Allen Bradley units that are about 15 years old. They are running 4 60 hp blower motors. These motors weigh about 500 pounds each so they are no fun to change out. I'm going to have to check to see if my motors are VFD rated.

 

[txhvac]

trane uses ceramic bearings and brush kits on their vfd centrifugals

Trane does not use ceramic bearings on their AFD CTVs. There are "oiless" machines out there, not too many, that use ceramic bearings, but they're not a factory standard. They do use the grounding brush on the refigerant cooled AFD machines for tail bearings.

 

[rotaryfrk]

I replaced a 10hp motor 3 years ago, about 1 year ago it began to make a noise that reminded me of a dry or dirty bearing. It was the same noise that made me replace the motor 3 years ago.

I replaced the motor this week, if I spin the shaft it makes a faint grinding noise. After reading the link that Absrbrtek posted I am wondering if I should ask my motor repair shop to install ceramic bearings to possibly rule out this type of failure from happening again?

This motor is controlled by a VFD but it is not set up to go any higher than a frequency of 40. It has run 24/7 at 40 for 3 years. Could that factor be contributing to the same failure that repeatedly occurrs.

 

[chiller32]

We'll according to brand "Y", brand "T" has problems due to the carrier frequency. That's why brand "Y" has less bearing failures. Not sure if this is completely true but I hear more complaints about brand "T" VSD chillers.

Yorks compressor bearings are sleeve type first off second with an open drive compressor the motor can be sent off/ or replaced to handle VFD's, Trane's rear compressor bearing's are roller and thats where the problems are from. That would probably explain why Yorks don't fail as often as Trane.

 

[19c357]

This issue was brought up at the Centrifugal disassembly/reassembly class in o5, Syracuse training center. Instructor Greg Reiber showed us two different motor end bearing for 19xr . Constant & variable speed. The motor with VDF,end bearing,had additional oil groves.

19xr dosent have tail bearing.

 

[gsxrsquid]

Over the years I have seen many motor bearings fail due to eddy currents generated by the VFDs.

 

[sodd81927]

Why replace motors with bad bearings? why not just replace bearings? most large motors have bearing #'s on data plate .Just me thinking...

 

[gsxrsquid]

you can replace the motor or just the bearings but if you don;t resolve the eddy current problems the bearings will eventually fail again.


The best VFD problem I saw was a 50 hp motor that detonated. No one was in the room at the time but they heard the boom and we found pieces of the motor housing all over the room. big chunks of iron.

 

[consolidmech]

What I meant is the bullhead bearing ( low speed bearing )

 

[stickerhead]

You mean "bull gear" bearing? Usually the bearing on the large gear attached to the low speed rotor shaft.

 

[supertek65]

You mean "bull gear" bearing? Usually the bearing on the large gear attached to the low speed rotor shaft.

yeah bull gear!

 

[gsxrsquid]

hey Supertek! I like the avitar. Is it an old G.E. with the exciter driven off the end of the shaft? I used to operate 2 of them hung off skinner steam engines. Ahh the good old days

 

[supertek65]

hey Supertek! I like the avitar. Is it an old G.E. with the exciter driven off the end of the shaft? I used to operate 2 of them hung off skinner steam engines. Ahh the good old days

wow!

you are the first person to recognize it.
yes 1926 worthington steam generator.
down town kcmo the fan is still in operation.

 

[gsxrsquid]

awesome. Just one or a couple? we had a 250kva and 350 kva with manual syncronization

 

[supertek65]

gsxr,
by the way is gsxr a sukuki motorcycle?
I would be lying if I said I knew much about this stuff.
There is only one. we are working on the two cvhe 025's in the same place.
I just thought this stuff was really cool and took some pictures.
I have a friend in my rses chapter, Nick, he used to work at this theater in the 50's. who ever put this stuff in in the 20's had to have been a genius!!!!!!


www2.hawaii.edu/~angell/thsa/gl-loews.html

 

[plee]

Supertek,
I don't know if youre the John Clark that worked for Fagan several years ago but the name seems familiar.

 

[supertek65]

plee

Supertek,
I don't know if youre the John Clark that worked for Fagan several years ago but the name seems familiar.

no,
i just stole that quote from john.

he is a compressor guru from my rses chapter.
he is the president of compressor remanufacturers of america or something like that.

hands down the smartest compressor guy ever.
wes taylor from carlyle could not hold his jock!