Manitowoc MLC650, Service Maintenance Manual

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Reference
Only
ACCESSORIES MLC650 SERVICE/MAINTENANCE MANUAL
10-68
Published 09-09-16, Control # 229-09
Active Fixed Mast Stop Operation
Hydraulic Supply
See Figure 10-55 for the following.
The hydraulic supply for the active fixed mast stop (AFMS)
system is provided by the accessory pump. The mast
cylinder system pressure-reducing valve (11) decreases the
accessory pump pressure to the cylinder operating pressure
of 31 bar (450 psi).
Normal Operation—Cylinder Extension
See Figure 10-55 for the following.
When the compressive load decreases on the mast stop
cylinders, the pressure in the bore (piston) side of the
cylinder decreases. When hydraulic pressure in the bore
side of the cylinder decreases below the regulated supply
pressure, the check valve (6) opens and allows hydraulic
fluid to flow into the bore side until the pressure in the
cylinder and the regulated supply pressure equalize. When
this happens, the check valve closes.
FIGURE 10-55
Cylinder Extension
Item Description
1 Mast Stop Cylinder
2 Relief Valve (set at 221 bar [3200 psi])
3 Integrated Cylinder Accumulator
4 Relief Valve (set at 16,6 bar [240 psi])
5 Mast Cylinder Pressure-Reducing Solenoid Valve
6 Check Valve
7 Mast Cylinder Directional Control Solenoid Valve
8 Rupture Disc
9 Bypass Check Valve
10 Mast Cylinder Pressure Transducer
11 Mast Cylinder System Pressure-Reducing Valve
(set at 31 bar [450 psi])
12 Mast Cylinder System Pressure Transducer