You should have either a ground ring or ceramic bearings in the motor if it's being used with a speed drive.
Sent from my iPhone using Tapatalk
While at a location working late in the day trying to get this unit up and running, the building manager walks up and asks me to check another unit that is making noise down in the space. I find its the R.A. motor with a failed opp. Bearing. I shut it off at the drive and told him ill be back tomorrow. The oem motor is a baldor cat # em3218t. Although ill know more tomorrow, i didnt think it had a ground ring on the shaft, if it dosent im going to suggest getting one from baldor with a ring, rather than another oem w/o one. Thats what i had to do with a couple trane units a few years back.
Model # RN-040-3-0-BB04-3C9, S# 200811- BNGV04444
Just figured i would see what anyone else thinks, thanks
You should have either a ground ring or ceramic bearings in the motor if it's being used with a speed drive.
Sent from my iPhone using Tapatalk
Quickly, I must hurry, for there go my people and I am their leader!
can you even get a non inverter rated motor today?
R I P Icemeister
Supporting our Vet’s
http://www.soldierride.org/
http://www.woundedwarriorproject.org/
Most motors are inverter rated. Most dont ship with a ground ring. We use the gold Baldor motors are supplier usually installs a ring for us a sets it up to what mount we specify f1,2,3.
I truly believe most manufatures only care if a unit makes it out of warranty. That being said a general duty motor will run on a drive and most likely make it a few years. It will slowly begin to sound like hell till it fails. I found this on the Aegis website.
"All major manufacturers of 3-phase AC induction motors
offer “inverter-duty” or “inverter-ready” models, but while
these motors have inverter-rated insulation to protect the
windings, their most vulnerable parts — the bearings —
are too often ignored. Without some form of mitigation, shaft
currents can discharge through bearings, causing motor
failure and downtime. To be considered truly “inverter-ready”,
a motor must have proven long-term bearing protection —
an AEGIS® Shaft Grounding Ring — in addition to inverter-
rated insulation. Unfortunately, many purchasers of these
motors do not understand this. And, mission-
critical facilities, in which downtime can have disastrous
consequences, are especially vulnerable to motor failures."
So inverter rated is just better winding insulation and a better cooling fan to help at lower frequencies, sometimes a grounding ring is factory installed sometimes not. Sometimes internal sometimes external.
I believe all that to be true , that's why i was thinking oem might not be the way to go, but it doesn't seem to be a high priority at my company, i got sent to a another job this morning so i turned it over to the office , they did nothing, and monday im going somewhere else, so idk?
you have to be careful with Aaon units. they don't use cheap motors, so installing a generic, same HP, will bite you in the butt. you have to pay attention to insulation rating and amp draw when sourcing something other than OEM. even then, a non OEM may fail quickly.
when purchasing motors, you have to recognize that HVAC manufacturers contract motor manufacturers to supply a specific product for their units only. these motors may "look" the same as any other with the same frame size, but can be vastly different.
Leave it up to Aaon to be a pain in the ass. I've came across this scenario on a condensing unit with nuisance high head pressure trips because the CFMs were replaced with non-OEM motors that were rated at a lower ambient temp and would overheat