Clarke CA60 20B, Service Manual, Page: 64 / 91

Service Manual-CA60 34 Scrub System REV (CA60 20B/24B) 61
Brush Deck Actuator Function (only for CA60 20B/24B)
The brush deck actuator of CA60 is controlled directly by the main control board without extra electromechanical limit
switches or position switches, The actuator does not require adjustment. The controller learns the position of the actuator
by watching for when the motor amperage draw increases when it comes to a mechanical stop at the top of its travel.
Each time the machine is powered on, the controller fully retracts the actuator to learn the
“home” position. When the
controller extends the actuator, it monitors and counts the pulses created as commutator bars move across the carbon
brushes, In this way it always knows how many pulses, or motor rotations, the actuator is from the home position. In
others words, once the controller has learned the home position of the actuator, it always knows exactly where it is
positioned without the need of any additional inputs and the controller is able to stop the actuator motor exactly at the
desired position.
The actuator moves and stops in 3 defined positions
：
1. RETRACTED: fully retracted end of stroke (deck lifted)
2. WORK: intermediate position which is established by the controller monitoring how far the actuator has traveled and
shutting off power to the motor when it reaches the desired positon. (deck on the floor, normal work condition)
3. EXTRAPRESSURE: fully extended end of stroke (deck on the floor with extrapressure given pressing the actuator
integrated spring)
The machine switch-on reset feature moves the actuator from the position where it was the last time the machine was
switched off to the RETRACTED position.
The actuator strokes, with a tolerance of +/-2mm are:

stroke RETRACTED-WORK=4.5 in (115mm),

stroke RETRACTED-EXTRAPRESSURE(end to end) =5.7 in(145mm)