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 Occasionally, an inspector will find a sheave with one or more unused grooves. Most of the time
it is not used by design, but it never hurts to check the cross head data tag to verify. It is good
practice to confirm the data for the actual rope size and construction because mistakes are found.
2.5.5 Guards
Many times guards are removed to service equipment and in haste are not returned to their
proper place. All guards must be in place and securely fastened.
A thorough check of the hoist machine gears and bearings should be made on each inspection
trip. (See Figure 2-11 and 2-12). Problems in these areas do not happen over night. If found
early, they can greatly reduce repair costs and time. Bearing problems are detected by sound
and/or heat. Gear problems are detected by examining the wear pattern on the gear. This will
show that the gear is not properly aligned with the worm causing the point of contact to be not in
the proper position or that the gear is bottoming or contacting the worm shaft. Excessive heat
damage, most likely caused by low oil or break down of oil, can also be detected. It is indicated
by pock marks in the face of the gear tooth or teeth. (They resemble casting defect marks).
2.5.7 Hoist Motor
It is very important to check the hoist machine motor. Commutator or slip rings damage are
indications that something is not right and needs immediate attention. (see Figure 2-13). Become
very familiar with these signs and be constantly on the look out for them. Elevator performance
is directly related to good electrical continuity through the commutator or slip rings. Also, heat is
always a major concern and is a problem indicator. The source of the heat should be investigated
and corrective action recommended. Motors should be kept clean to assure proper air passages
which are needed for cooling. Connections not properly made may result in poor electrical
conduction and points of resistance. This condition creates heat. Improper adjustments can force
motor windings to carry more current which produces heat and this heat will cause insulation
to deteriorate.
2.5.8 Brake
Closely examine both the mechanical actions of the brake, and the electrical components. The
A17.2 Manual addresses the examination of the mechanical action. As for the electrical
components, the brake coil leads, connections, and windings should be examined to check
insulation conditions and physical connections.
2-22
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