American Rotary Phase Converter making noise

[Ulma Doctor]

i have serviced 3 phase industrial motors that have been over-greased to the point of pushing the shield or seal off the bearing
the field housings rapidly get a smearing of grease

 

[NCjeeper]

Maybe one of the fan blades flexing and touching the housing?

 

[Scra99tch]

Reminds me of when I sold a 30 HP converter. Ran great when it was warm and had a guy interested in it come up from Georgia to NH. He arrived on an October day and it hit 25F that night. When he came in the garage was probably 29F. Needless to say when I turned it on it squealed like no other. I was a bit embarrassed and he was ******. I knocked a few bucks off an already great deal and endlessly tried to assure him this had just happened.

Oh well.

 

[Janderso]

I have the exact same RPC, and mine does the exact same thing. Has done it ever since I bought it. In the warmer months, it never happens. But now that the weather is cooling down, it's back. What I've discovered is that if you turn the power off; wait about ten or fifteen seconds and power it back on, it usually stops. In very cold weather, it may take a little longer. When I first noticed it, I would let the motor spin all the way down to a complete stop, which takes a pretty good while. By chance, I discovered that's not necessary. Mine is few years old, and it's never failed. I've just grown accustomed to dealing with the nuisance.

Regards

Well that's good news.
I won't worry about it.
Thanks

 

[Janderso]

you could try tilting the motor to one end and run it, then tilt it the other direction-
that would surely intensify the noise in a bearing starting to fail.
if the noise goes away on one side tilted, you have a place to start
6307-2RS-C3 bearings are most likely contained within the motor housing

Thank you Mike.

 

[Kevin T]

Mine surprises me from time to time with new sounds. Seems like each time it is because it has moved over and is making contact with something. Not sure if this is your issue. Do you have isolation mount feet? I am also replying because I see you are keeping track of lube intervals and I....gulp...have not lubricated mine yet after a year of light use. What should I use on those zerks? and how much? I am assuming quite a bit less than the front end tie rod of my rusty FJ40 that has a torn boot!

 

[Janderso]

Mike (Ulma Doc) set me up with a Mobil product for electric motors. One pump once a year should do it. IMHO

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[keeena]

That RPC is far quieter than mine (just from a volume perspective, I don't have that intermittent noise). What HP is that unit?

Mine is an American Rotary controller but has a 3rd-party idler. 15hp.

 

[tjb]

FYI update, Jeff, on noise coming from RPC.

We had a string of unusually cold, damp days a couple of weeks ago, and during that period my idler (American Rotary's official name for the motor) began squealing for far longer periods of time than normal. It got me concerned, so I contacted tech support at AR. They gave me a few things to check, none of which helped the situation. It was beginning to sound like the bearings were going bad. I asked about the purpose of the zerk fittings. (Mine has two - one on each side of the the motor housing, where it appears yours only has one.) The tech guy told me those don't actually grease the bearings (those are sealed); they grease the housing the bearings ride in. On a whim, I shot a little more grease into both fittings, and the sound went away. Totally. Now, even on initial startup on a cold day, I get no noise at all.

I added the grease while the RPC was running and only put a little at a time. Improvement was pretty evident almost immediately. But as Mike (Ulma Doctor) noted, there may be a potential danger from adding too much grease. I dunno. It worked for me, but he's way more of an expert with stuff like this, so if you try it, be careful.

Regards

 

[woodchucker]

FYI update, Jeff, on noise coming from RPC.

We had a string of unusually cold, damp days a couple of weeks ago, and during that period my idler (American Rotary's official name for the motor) began squealing for far longer periods of time than normal. It got me concerned, so I contacted tech support at AR. They gave me a few things to check, none of which helped the situation. It was beginning to sound like the bearings were going bad. I asked about the purpose of the zerk fittings. (Mine has two - one on each side of the the motor housing, where it appears yours only has one.) The tech guy told me those don't actually grease the bearings (those are sealed); they grease the housing the bearings ride in. On a whim, I shot a little more grease into both fittings, and the sound went away. Totally. Now, even on initial startup on a cold day, I get no noise at all.

I added the grease while the RPC was running and only put a little at a time. Improvement was pretty evident almost immediately. But as Mike (Ulma Doctor) noted, there may be a potential danger from adding too much grease. I dunno. It worked for me, but he's way more of an expert with stuff like this, so if you try it, be careful.

Regards

I don't understand what it means to grease the housing... The bearings are the only thing moving, you don't grease the housing so the bearings spin in the housing. Sounds like the grease goes into the bearings. Glad you resolved it.

Did AR explain what the grease does in the housing????? Inquiring minds want to know.