2.5.3 Speed Governor
Inspection of the speed governor is a very critical part of the inspection. The A17.1 Code and
A17.2 Manual specifically address the inspection requirements for this device. It is one half of
the function that makes elevators safe with the car safety device being the other half. The
certified inspector should follow the steps outlined in the A17.2 Manual as close as possible to
assure nothing is overlooked. Always be aware that governor parts do wear, and governors do
have to be rebuilt or replaced. Leaking or exposed lubrication is a good indication of
deteriorating seals, enlarged openings resulting from wear, or worn gears. Also, be sure
governor seals are in place and that they are properly located. The seal most used is the lead
block and wire type, but there are other types which provide the same degree of security. The
seal is used to indicate whether adjustments have been modified from set position. Be sure that
seals are placed in such a position that they are broken if adjustment changes are made.
Occasionally, seals are found in a position that modification can be made and the seal remains
intact. Mistakes in the type or size of governor rope are often found. Governors are designed to
operate with a specific size and type of rope. Any change will alter the operation of the car
stopping mechanism. An example of this is a rope of smaller than design diameter, which could
allow the governor jaw to close without gripping the governor rope, thus resulting in the car
safety not applying. Changes in the type or size of the specified hoist ropes will change the rope
to a sheave traction factor resulting in either insufficient traction or excessive traction. Either
condition can result in dangerous consequences. Insufficient traction results in the drive
machine losing control of the car and counterweight. This could result in an overhauling load
from either side, causing a runaway condition. Too much traction could result in the machine
lifting either the car or counterweight if the other were to stop and the machine continued to run.
The traction factor is extremely critical to safe elevator operation.
2.5.4 Traction Sheave
Traction sheave wear is usually just detected by finding metal particles under the sheave.
However, an inspector should watch for the signs that lead to wear before you see the results.
The major cause of wear is uneven rope tension. The sheave is designed to carry the load spread
over all the ropes. When one is under more tension than the others, this load is transferred to the
tighter rope. This can usually be seen by laying a straight edge across the ropes in the drive
sheave grooves. (See Figures 2-9 and 2-10). All ropes should touch the straight edge. Ropes that
do not touch indicate uneven tension or possible sheave wear.