NBT50 OPERATOR MANUAL CONTROLS AND OPERATING PROCEDURES
National Crane Published 03-23-2018 Control # 243-14 3-15
be no evidence of binding. Any damage or leakage
should be repaired immediately.
• The RCL and anti-two-block system for proper
operation.
• The electrical wiring connecting the various parts of the
system for physical damage.
NOTE: Consult the truck manufacturer’s manual for
vehicle checks.
Cold Weather Operation
The following recommendations are for operating National
cranes in very low (i.e., sub-zero) temperatures.
Cranes should have appropriate hydraulic oil, lubricants, and
other auxiliary items required for operation in sub-zero
temperatures. Operate individual crane functions to ensure
they are sufficiently warmed prior to performing a lift.
Operation of cranes at full rated capacities in temperatures
between -9°C (15°F) and -40°C (-40°F) or lower should be
accomplished only by competent operators who possess the
skill, experience, and dexterity to ensure smooth operation.
Shock loading shall be avoided.
Operation Below -40°C
For crane operation below -40°C, capacities shall be derated
3.67 percent of the rated load shown on the capacity charts
for each degree below -40°C.
Operation Below -40°F
For crane operation below -40°F, capacities shall be derated
2 percent of the rated load shown on the capacity charts for
each degree below -40°F.
CRANE WARM-UP PROCEDURES
The following procedures detail the actions that must be
taken to properly warm the different crane components
before operating the crane.
NOTE: For temperatures below -9°C (15°F) refer to arctic
lubricants and conditions in the Operator and
Service Manuals.
Before starting the crane, ensure the appropriate lubricants
are used to provide lubrication for the prevailing ambient
temperatures in which the crane will operate in (a list of
lubricants and their temperature ranges can be found in the
Lubrication section of your crane’s Operator Manual, by
contacting your local Manitowoc distributor, or by contacting
Manitowoc Crane Care directly).
Engine
NOTE: For National Crane engine warm-up procedures,
refer to chassis manufacturer’s manual.
Warm-up Procedures for All Temperature Ranges:
1. Upon startup, allow the engine to idle for 3 to 5 minutes
before operating with a load.
2. Cold Engine Startup: After allowing the engine to warm
by idling it for 3 to 5 minutes, slowly increase the engine
speed to provide adequate lubrication to the bearings
and to allow the oil pressure to stabilize.
Transmission
NOTE: For National Crane transmission warm-up
procedures, refer to chassis manufacturer’s
manual.
Operating the transmission with a sump temperature below
normal operating temperature is limited to:
• operating in the neutral gear or
• driving with an unloaded crane while not exceeding
1500 engine RPM and not exceeding half throttle.
Alternate Warm-up Procedures for Truck Mount (TM/
TMS) Cranes:
1. Setup the crane on outriggers.
2. Engage the transmission and allow crane to run at idle
until the temperature of the transmission sump reaches
normal operating temperature.
Hoist
Performing a warm-up procedure is recommended at every
startup and is required at ambient temperatures below 4°C
(40°F).
CAUTION
Crane Damage Hazard!
Operating the crane with the incorrect lubricants and
fluids for the prevailing ambient temperature and/or failing
to adequately warm the crane prior to cold weather
operation can lead to a failure of a crane component or
system.
Always use Manitowoc recommended lubricants and
fluids for the prevailing ambient temperature and properly
start and warm the crane using the cold weather
procedures found in this Operator Manual and
supplement before operating the crane at full load.
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