Operation; Control Circuit Components - nifty Heightrider SP HYBRID Series Operating/Safety Instructions Manual

4

Operation

4.1

CONTROL CIRCUIT COMPONENTS

4.1.1 GROUND CONTROLS
MASTER PROGRAMMEABLE LOGIC CONTROLLER (PLC): - Situated under the ground controls
canopy, behind the Ground Controls Station is the Master PLC. The main purpose of the Master PLC is
to process signals received from all areas of the control circuit on the machine and where appropriate
output these to a series of smaller digital modules to operate the relevant machine functions.
Also, during machine operation, the Master PLC is constantly receiving signals from the Platform PLC
(see Section 4.1.2) in order to monitor Safety Critical Functions. If for some reason any of these
functions became inactive the Master PLC would immediately disable the machine.
TILT SENSOR: - Fitted to the superstructure behind the ground controls canopy, the tilt sensor is a
solid-state sensor, which monitors the inclination of the machine chassis. When the platform is in use,
i.e. Booms are raised, if the inclination exceeds the pre-set limit, it will disable all drive functions and
sound the alarm. In order to recover the machine, boom operation is unaffected, allowing the operator
to restore drive by lowering the booms into the stowed position. It is then possible to drive back onto
level ground, fully restoring machine operation.
MULTI-TONE SOUNDER: - Situated inside the ground control station is a small electric sounder, which
is used to provide an intermittent beep whenever the machine is in operation. Pushing a green "power
control" button or depressing the foot switch in the platform will energise this sounder. This serves to
warn personnel of the operation of the machine. In addition, it is this device which produces a ricochet
type sound if a safety critical problem has been detected i.e. Tilt angle or Cage weight limits have been
exceeded;
Cage Weigh: - If the electronic load cell detects an overload condition it will sound continuously in
conjunction with the cage overload warning light.
Battery management: - when a low battery state is reached, the "pulsing" of the D.C. motors is
mimicked by the sounder reinforcing the message to the operator to charge the machine. Note; if
the sounder activates whilst using electric power only, it is advisable to start the engine enabling the
operator continued use of the machine, whilst recharging the batteries.
HORN: - Located on the side of the ground control box is a horn, which is used as a manual alert, by
pushing the "Horn" button on the Platform control panel.
BOOM SWITCH: - Mounted on the links knuckle and operated by the raising of link booms or upper
boom, this switch controls both the operation of the Tilt Sensor, and the speed control function. With
the booms in the stowed position, the Tilt Sensor is by-passed, allowing the machine to negotiate
slopes in excess of the permissible working angle, without isolating the drive function. At the same
time, High Speed drive (Depicted by a Hare Icon) is possible. When the booms are raised the Tilt
Sensor is activated and only Slow Speed drive is permitted. These control functions are of primary
importance to safety of the machine and operator; under no circumstances should this control
function be isolated or by-passed.
TELESCOPIC BOOM SWITCH: - Mounted inside the telescopic boom, this switch controls the
operation of the Tilt Sensor and Speed Control function as described in the previous paragraph.
English/USA – 11/13
Original instructions
Height Rider/SP Series
Operating & Safety Instructions
21