Rigid vs floating vibration measurement
Rigid vs floating vibration measurement
(OP)
We are looking for the correct means of measuring vibration in terms of should the object be rigidly mounted or can it sit on a foam pad.
The objects are either small psc motors (42, 48 frame) or motor/blower wheel assemblies. Based on different person's experiences, we debate on whether the object should be rigidly secured (ideally like in the end application, which isn't always possible) or if sitting it on a foam pad is acceptable.
Doing relative measurements (motor 1 vs motor 2) I suppose it doesn't matter, but to trouble shoot issues or establish a repeatable baseline measurement I would think it does.
I'd like to get some other people's experience plus reference to standards that are clear. I say clear because anything that seems to reference NEMA motor frame sizes and test methodology get a little wishy washy in these frame sizes.
The objects are either small psc motors (42, 48 frame) or motor/blower wheel assemblies. Based on different person's experiences, we debate on whether the object should be rigidly secured (ideally like in the end application, which isn't always possible) or if sitting it on a foam pad is acceptable.
Doing relative measurements (motor 1 vs motor 2) I suppose it doesn't matter, but to trouble shoot issues or establish a repeatable baseline measurement I would think it does.
I'd like to get some other people's experience plus reference to standards that are clear. I say clear because anything that seems to reference NEMA motor frame sizes and test methodology get a little wishy washy in these frame sizes.





RE: Rigid vs floating vibration measurement
Cheers
Greg Locock
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RE: Rigid vs floating vibration measurement
RE: Rigid vs floating vibration measurement
based on the GM spec.
It has some rules as to what resiliently mounted motor really means, and how to do it, and what reasonable tolerances might be.
About the only danger is if the final as-used mounting has resonances, in which case good motors will act badly, but no test system can prevent that.
RE: Rigid vs floating vibration measurement
I agree with the above comments that as a user, you want to see it mounted as close as possible to the way it's going to be used.
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