National Crane 600H, Service Manual

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10
3
NATIONAL CRANE
08-19-2022 Control # 092-13
3-5
600H ELECTRIC SYSTEM
Oil Cooler
The oil cooler core must be kept clean to allow for air flow
through the core. Wash the core frequently to eliminate oil
film, road dirt, and other foreign object buildup (Figure 3-5).
A 15 psi relief valve in the return circuit regulates the flow
through the cooler. When the oil is cool, most of the flow
bypasses the cooler and goes directly to tank. As the oil
heats up, more flow is diverted through the cooling core.
A temperature sensor in the cooling core turns on the electric
fan motor when the oil temperature reaches about 140° F
(60° C). The hydraulic oil needs to be under 210° F (98.8° C).
To quickly cool the oil, cycle the telescope or lift cylinders to
exchange the cool oil in the cylinders with hot oil in the
reservoir.
Cooler specifications is as follows:
Fan RPM .................................................................2450
CFM ...........................................................................863
Voltage ................................................................ 12 VDC
Stall Amps ....................................................................20
Operating Amps............................................................16
Temperature switch ................................... 140° F (60° C)
0il flow 180° F (82° C)...............30-50 gpm (113-189 lpm)
NOTE: Oil flow through cooling core with engine at
governed RPM.
RSOD Outriggers
Solenoids
FIGURE 3-4
REFERENCE ONLY