Manitowoc National Crane NBT30H-2, Руководство по обслуживанию

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HYDRAULIC SYSTEM NBT30H-2 SERVICE MANUAL
2-16
03-20-2019 Control # 613-06
1. Install a hydraulic pressure gauge to the pump gauge
port on the directional control valve (Figure 2-2).
2. Idle machine with PTO engaged. Verify that the
maximum pump pressure is at the correct setting (see
table above).
3. If maximum pressure is not correct; adjust the pressure
compensating control on the piston pump (see
Figure 2-15).
4. Shut down the engine.
5. Remove the pressure gauge and plug the pump gauge
port.
Telescope In and Telescope Out Reliefs
The telescope relief pressures are preset and not adjustable.
To check the telescope relief pressures do the following:
1. Remove the extend and retract (work port) hoses from
the telescope cylinder (Figure 2-4) and cap the
telescope adapters.
2. Attach a pressure gauge to the telescope extend hose
and plug the telescope retract hose.
NOTE: Install a gauge in each line, in turn, and check the
extend and retract pressures as described below
with telescope control lever.
3. Start the engine and set the throttle to governed RPM.
4. Push the telescope control lever to extend.
5. Relief pressure should be 19.65 MPa (2850 psi).
6. Shut down the engine.
7. Move the gauge to the retract line and plug the extend
line.
8. Start the engine.
9. Pull the telescope control lever to retract.
10. Relief pressure should be 20.5 MPa (2975 psi).
11. Shut down the engine.
12. Remove the pressure gauge and plug from the hoses.
13. Reconnect the telescope cylinder hoses.
Swing
The swing relief is preset and not adjustable. To check the
swing relief pressure do the following:
1. Disconnect the work port hoses at the swing motor.
2. Connect a pressure gauge to one line and plug the
other.
3. Start the engine and set to governed rpm.
4. Activate the swing control lever. The relief should read
2975 psi (+100/-50 psi) (20511 kPa (+689/-344 kPa)).
5. The relief valves are in the directional control valve and
are preset.
Outriggers Maximum Pressure
1. Select a front outrigger and remove the retract line from
the outrigger extend cylinder.
2. Install a pressure gauge in the retract line (Figure 2-8).
3. Start the engine and set the throttle to governed RPM.
4. Activate the retract function for the selected outrigger.
Adjust the relief pressure to 20684 +689/-0 kPa (3000
+100/-0) psi). The relief valve for the outrigger circuit is
located on the pump manifold (Figure 2-6).
FIGURE 2-4
Telescope Cylinder
Work Port Hoses
Rear of
Boom
Swing Motor
Hydraulic Hoses
FIGURE 2-5