Genie ZX-135/70 Service Manual page 247

Service Manual
Limit Switches and Angle Sensors
Types of Limit Switches
There are two types of limit switches, found in
various locations throughout the machine:
mechanical-type operational/safety switches and
rotation or angle sensors. As in aircraft, which
features redundant safety systems, each
mechanical operational switch is backed up with a
separate, independently functioning safety switch.
The mechanical-type operational or safety
switches are used to sense a positive
displacement or movement of the limit switch
actuator, or arm, as the machine moves through its
range of operational functions. The rotation or
angle sensors utilize Hall Effect technology and
must be calibrated when replaced. Included in this
group are envelope limit switches which sense the
extended length and angle of the booms and
rotational position of the turntable.
For example, when the secondary boom is fully
raised and the operational sensor is activated, it
tells the ECM at the ground controls to start
extending the secondary boom.
Another example is the drive enable limit switch,
which disables the drive function anytime the boom
is rotated past the rear tires, indicated by the
'circle' end of the drive chassis.In some cases, the
engine will be stopped if safety parameters are
exceeded.
232
LS
LS Limit FA
Switch
LT Stringpot RA
RS Rotary LF
Sensor
LR
RF
RR
J
P
T
Limit Switch Numbering
LSP1RO
LSP1EO
LSS1RO
LSS1RS
LSJ1RO
LST1O
LST2O
LST1S
LSFA1ES
LSRA1ES
ZX-135/70
Numbering Legend
FA 1 L
Front Circuit L Load
Axle Number moment
Rear A Angle
Axle
Left D Down
Front
Left Rear E Extend
Right R Retract
Front
Right
Rear
Jib Boom
Primary
Boob
Turntable
Primary boom length retracted
Primary boom length fully extended
Secondary boom fully retracted
Secondary boom fully retracted, safety
Jib boom length fully retracted
Drive enable, left direction
Drive enable, right direction
Drive enable safety, retracted axles
Front axle fully retracted
Rear axle fully retracted
Part No. 218700
August 2014
O
O Operational
S Safety