Identify a mystery noise

When was the last time you saw Grandma ?

I'd definitely call a refrigeration guy to check it out. Thumps, hoo-wees, chigga-chiggas and squeals and whistles are seldom good news.

I just shop there, it's a Food Lion. First time I heard it, I thought I was just hearing the bass thump on a music system. Then I realized there was no music, just this repetitive thump over the refrigeration aisle.

It's a low thump like jumping on the floor. But there are higher frequency components I can hear as well.

My question is really what kind of equipment cycles at this speed. Is one per second normal for some kind of recip? is that piston noise, valve noise, what?

What you're hearing is likely a fan blade hitting something, due either to a loose mount or a bad bearing. Kind of like when Stormy mormy opens his trap.

I havn't heard that kind of noise myself, so I've got no experience to go on. Wish I could give you a couple educated guesses.

Could be. Heck of a slow fan though, right? 1 cycle per second? that's 60 rpm.

It may remain forever a mystery, unless one of you guys maintains Food Lion refrigeration compressors.

I think Paul means if there's a motor mount loose, the fan will be moving around (back and forth?) and possibly hitting the housing about once a second. I once serviced a drink machine doing exactly that. It was caused by an iced-up evaporator that broke the motor away from its mount.

Bad bearings inside motors also tend to "clang" or "thump" about once every second or two.

Another possibilty... I once serviced an old condensing unit that was making what I thought was a fan bearing noise but when I got closer I realized the sound was coming from one of the bolts holding the compressor in place. A couple of drops of oil and the noise vanished.

They must know somebody who can check it out.

-------------------------------------------------- DocE

"The future ain't what it used to be." -Yogi Berra

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