ScusaMe, thanks for your input i'll certainly follow the links that you have posted as i clearly need to understand more about vibration and motors in general.
electricpete, I'm hooking up later with a trainer from UESystems to help me analyse some of my issues and will post further information...
ScusaMe, all the info i can get is that the motor is 3 phase, 6600volts, rpm 2990 and that it is an ex rated motor as it is located in a gas storage area.
Skogsgurra, On site there 3 different locations for these 3 phase 6600v blower motors. Each location has 4 motors and named as phase 1, phase 2, phase 3 [just a location name] on 1 motor on phase 1 the NDE has the 100hz issue as does 1 motor on phase 3.
Would i be correct in assuming that if...
Thats very interesting as i have found the same symptom on another motor at another location but on the same site. If this is a supply problem what would be the best way to prove this issue compared to a bearing issue.
Dan another company do the vibration analysis what i find using ultrasound is a buzzing sound which is backed up by a spectralyzer showing dB and hz, basically i find peaks every 100hz with a small peak every 50hz which indicates fluting. As we are 50hz supply thats where i'm looking for...
Thank you for your kind reply although i have just been told that these motors may be DOL so i assume the problem of discharge through the bearings must be comming from some other source perhaps. I assume i would now need to use a voltmeter and test the motor casing to earth.
I'm currently undertaking ultrasound inspections of some 6600 volt soft start motors and appear to be getting indications of fluting whereby i might be getting a discharge to earth through the motor bearings.
Iknow VFD controlled motors can cause an induced voltage on the motor shaft but not...
