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Equipment Installation

Equipment Installation

Equipment Installation

(OP)
We have just installed 2 new 1.2 Mw induction motors,4000v/1800 rpm, in a new rock crusher application.These motors weigh approx 11 metric tonnes.
My problem has to do with the size of shim stock used under motor feet.Common sense and good practice would tell you that"shims"should support the motor weight, and if not, it should have at least an area of 75% of the total size of the motor feet.In this case (not the first time either)the size of the shimstock used  is really miniscule.The motor mounting feet total area is about 96 SQ/in,but the size of the "shim" under it, is only approx 16 SQ/in.
This is no "Rocket Science" ,motor shims should have adequate surface area to support motor static weight plus the Torque forces developed,which can be very large on a large drive.
MY problem has to do with the lack of a Standard mechanical/electrical  that spells out what the minimum size should be for "shims" under the  motor base.
OEMs recommend a "Shim" as large as the "foot" but no
EASA or any other Standard makes it kind of BK/WH.
A few years ago, we had 5 new motors,  3.5 Mw each and I notice the same practice being used.Motor shim "too"small
relative to motor foot print.This is very important for long term motor performance,low vibrations as well.

Thank you all in advance.
GusD

GusD

RE: Equipment Installation

Gus,
I think the shim cross sectional area
should exceed the bolt cross sectional
area by a factor of 1.5.  I assume
you have 4 bolts.

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