The AM Forum
July 20, 2024, 03:51:02 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
 
   Home   Help Calendar Links Staff List Gallery Login Register  
Pages: [1]   Go Down
  Print  
Author Topic: Fan bearing damage due to EMI from high power curcuits  (Read 1175 times)
0 Members and 1 Guest are viewing this topic.
Opcom
Patrick J. / KD5OEI
Contributing
Member
*
Offline Offline

Posts: 8284



WWW
« on: July 31, 2023, 08:22:27 PM »

The source is certainly a reputable manufacturer of fans and blowers. Seems to affect ball bearing fans. Has anyone any consideration or experience of fan bearing issues?

"Cautions for Use of a Cooling Fan in the Vicinity of a Power Switching Circuit
(prevention of electrolytic corrosion)"

https://products.sanyodenki.com/info/sanace/en/technical_material/powerswitchingcircuit.html

Logged

Radio Candelstein
WD8BIL
Contributing
Member
*
Offline Offline

Posts: 4406


« Reply #1 on: August 01, 2023, 07:54:39 AM »

Ya know Patrick, I never really considered that. The fans in our transient generators here in the lab do make quite a bit of bearing/bushing noise.
They run EFT and surge tests everyday in the 1-4KV ranges (61000-4 series tests). We just got a 3rd generator a few weeks ago. I'll keep an ear on it and see ifn the fan noise grows over time.

Interesting!

Buddly
Logged
W1RKW
Contributing
Member
*
Offline Offline

Posts: 4408



« Reply #2 on: August 01, 2023, 08:16:48 AM »

If there were some actual numbers in that piece I might believe it.  what level is considered high power/high voltage?  This is very subjective.  Maybe oxygen free monster cable will help.
Logged

Bob
W1RKW
Home of GORT.
K8DI
Contributing
Member
*
Offline Offline

Posts: 434


« Reply #3 on: August 01, 2023, 12:41:35 PM »

Bearing damage from discharge of electromagnetically induced voltages on a motor shaft is a known issue.

Here’s an approachable article:
https://www.vibescorp.ca/learn-about/shaft-currents/

Ed
Logged

Ed, K8DI, warming the air with RF, and working on lighting the shack with thoriated tungsten and mercury vapor...
W3SLK
Member

Offline Offline

Posts: 2677

Just another member member.


« Reply #4 on: August 01, 2023, 07:45:20 PM »

So back when I was a service engineer in a different lifetime, I repaired industrial balancing machines. One service call took me to GE Erie where I was met by the plant manager who said, "You gotta help me! I'm loosing $50MM a day!" Our machines were used to balance the armatures for the locomotive traction motors and the main armature for the locomotive alternator. Those armatures weigh about 10K lbs and are balanced at 900 RPM. Our machines were rated to weld on the work supports. However some new operator was welding the balancing weights in place with the ground not on the shaft of the armature, (it was a strap in the shape of a hook), he hooked the grounding clamp to the base of the machine! Arced through about $20,000 worth of bearing supports. When I spun the bearings it sounded like rice crispies! Don't use bearings as a 'path' to ground!
Logged

Mike(y)/W3SLK
Invisible airwaves crackle with life, bright antenna bristle with the energy. Emotional feedback, on timeless wavelength, bearing a gift beyond lights, almost free.... Spirit of Radio/Rush
Pages: [1]   Go Up
  Print  
 
Jump to:  

AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
 AMfone © 2001-2015
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Page created in 0.082 seconds with 19 queries.