Performance Motion Devices CME N Series, User Manual

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ION/CME N-Series Digital Drive Developer Kit User Manual 63
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This is achieved by the tab deliberately breaking (snapping) under conditions of over tightening. Such a protective fuse
break event (snap) of the tab should be audible to the operator during tightening. While an N-Series Drive unit that
has undergone a fuse break event during tightening is no longer usable, it serves as a signal to the operator to check
and revise their torque control procedure so that the tab mounting torque limits are not exceeded during future
attachment procedures.
3.7.2.4 Thermal Transfer Materials
Figure 3-8:
Recommended
N-Series ION
Thermal
Transfer
Material
Dimensions
Thermal transfer materials in the form of thermal tape, pads, paste, or epoxy may be used to improve thermal transfer
between the N-Series Drive’s metal plate and an attached heat sink or supporting plate. These materials improve
thermal conductivity by filling in air gaps that form when two metallic surfaces are mated.
Figure 3-8 shows a typical application of a thermal transfer material between the drive unit and a heat-removing metal
surface. The following guidelines may be helpful in selecting and sizing the thermal transfer material best-suited to
your application.
The capacity of thermal transfer materials to transfer heat (known as the bulk conductivity) is much lower than that
of metals such as aluminum or copper. Therefore, in general, the thinner the transfer material the better. Thickness of
the material is only precisely controllable for thermal pads and thermal tapes, with thermal pads providing the thinnest
An ION/CME N-Series Digital Drive which has undergone a fuse tab event (snap) during installation must be de-
installed and discarded. It is not possible to repair or to otherwise use an N-Series Drive unit which has undergone
a fuse snap event.
The N-Series ION's fuse-tab functions when there is an air gap between the bottom of the tab and the surface
that it is mounted to. If there is no air gap, or if the air gap is too small then the fuse/snap function may not occur
even though the recommended mounting torque limit may have been exceeded. In all cases it is the responsibility
of the user to determine that the recommended mounting torque limits or force indicated in
Section 3.7.2.2, “In-
stallation & Torque Limits,” are not exceeded.
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