Construction Mode
2-12 Manual # 42-02-7223 C1
Alignment of the tachometer coupling is extremely important. Most vibration problems are
caused by the tachometer or the way in which it was mounted. The tachometer mounting must
be rigid and the tachometer wheel must be aligned precisely with the surface it is running on
(i.e., the brake drum or drive sheave).
In geared applications, do not drive the tachometer from the sheave because gear lash cannot be
compensated by the drive unit.
Tachometer Wiring
The tachometer wiring must use a separate grounded conduit. Inside the controller cabinet, if
control wires must cross power wires, they must cross at right angles to reduce the possibility of
interference.
The cable must be routed into the controller cabinet in a separate conduit. The following illus-
tration shows the wiring at the controller end.
Figure 2.1 Tachometer Wiring
1. Connect the cable from the tachometer as shown above.
2. The connection to the controller TS connection must be positive (+) with respect to the
TC connection when the elevator is moving in the up direction.
3. DO NOT connect the cable shield at the tachometer end of the cable. Insulate any part of
the shield exposed at the tachometer end to prevent it from accidentally shorting to
ground. (Connecting the shield at the tachometer end may cause ground loop noise and
affect ride quality.)
iBox Connection End
Insulate shield at
tachometer end --
Do not connect the
shield to the tach.