Manitowoc Published 11-06-15, Control # 040-13 1-93
2250 SERVICE/MAINTENANCE MANUAL INTRODUCTION
The PC enables the MAX-ER’s electronic and hydraulic
systems to automatically extend and retract the
counterweight strap cylinders to raise and lower wheeled
counterweight assembly in response to changes in back
hitch tension:
• At 30 U.S. tons of tension on back hitch load sensing
pin, the strap cylinders begin to retract. At 28 tons of
tension, the strap cylinders stop retracting.
• At less than 4 tons of tension on back hitch load sensing
pin, the strap cylinders begin to extend. At 6 tons of
tension, the strap cylinders stop extending.
• If calculated strap cylinder load drops below 7.5 tons of
tension, strap cylinders stop retracting, because
wheeled counterweight trailer should be on the ground.
• If left side strap cylinder limit switch is tripped, neither
strap cylinder will retract.
The PC also monitors the pressure senders in both right side
and left side rod end strap cylinders and right side piston end
strap cylinder hydraulic circuit to control the raising or
lowering of the counterweight assembly when operating. The
operating pressure range is from 0 to 3,000 psi (0 to 207
bar).
2000 psi
WHEELED COUNTERWEIGHT TRAILER
X
(13.8 bar)
200 psi
XX
X
RM-14
HS41
HS40
T
LEFT STRAP
RIGHT STRAP
T
CYLINDER
CYLINDER
MAX-ER ACCESSORY VALVE
EXTEND
RETRACT
T
FIGURE 1-59
2200 psi
3000 psi (207 bar)
STOP CYLINDERS
FROM MAST
STOP CYLINDERS
TO MAST
MAST
ACCUMULATOR
T
TO JIB STRUT
CYLINDERS
JIB STRUT
CYLINDERS
FROM
PRESSURE
SENDER
ACCUMULATOR
MAST
(152 bar)
3000 psi
(207 bar)
(138 bar)
ACCESSORY
TO CRANE
CRANE
MANIFOLD
SUCTION
AUX
FAN
VALVES
HS12
DISABLE
SYSTEM
AUXILIARY
NOTE: Past units have an
unloader valve that cuts in
at 2,300 psi (159 bar) and
cuts out at 2,900 psi (200
bar).
To Next Page
Loading...
