Service Truck Crane Operator 4 Flashcards
6 cards from real NCCCO practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Service Truck Crane Operator 4 flashcards as text
What is a hydraulic lock valve (counterbalance valve) on a crane cylinder and what failure mode does it prevent?
Answer: A valve that holds hydraulic cylinder position by preventing fluid flow when the supply pressure is removed, preventing load-induced cylinder collapse if a hose fails
Hydraulic lock (counterbalance) valves hold the cylinder in position by blocking fluid from flowing out of the cylinder when the control valve is in neutral or when supply pressure is lost due to hose failure.
What is the significance of the manufacturer's minimum and maximum oil temperature range for service crane operations?
Answer: Operating outside the specified temperature range changes hydraulic oil viscosity, affecting pump efficiency, component wear, and seal integrity in ways that can compromise crane function
Operating hydraulic oil outside its temperature specification range alters viscosity, leading to inadequate lubrication, pump cavitation at cold extremes, or seal degradation and accelerated oxidation at hot extremes.
When a service truck crane is equipped with a load limiter system that disables functions above rated capacity, what should the operator understand about this system?
Answer: Load limiters are safety aids that may have sensor limitations or configuration errors; operators must still verify loads against load chart values independently
Load limiters provide valuable overload protection but are electro-mechanical systems subject to calibration errors, sensor faults, and configuration mistakes; they supplement but never replace the operator's independent load chart verification.
What is the correct procedure for adding hydraulic fluid to a service crane's reservoir?
Answer: Use only the manufacturer-specified fluid type from an uncontaminated, sealed container, and add through a filter or clean filling equipment to prevent contamination
Only manufacturer-specified fluid from a clean, sealed source should be added through filtered fill equipment, as contaminated or incompatible fluid can cause rapid seal and pump damage throughout the system.
What determines whether a service truck crane is rated as a 'Class I' (light), 'Class II' (medium), or 'Class III' (heavy) duty crane?
Answer: Duty class is determined by the crane's load capacity rating, intended application type, and the cycle frequency under which it is designed to operate safely
Duty class reflects the crane's design basis including load capacity, intended application frequency, and operational severity, guiding appropriate maintenance intervals and inspection requirements for the equipment's intended use profile.
What is the minimum safe distance from an excavation or trench edge when positioning a service truck crane for a lift?
Answer: Distance from excavation edges must account for the surcharge load of the crane, typically requiring setback calculated by an engineer or following OSHA minimum setback requirements based on soil type
Cranes impose surcharge loads that can cause excavation wall collapse; setback distances must be calculated to ensure crane loads do not exceed the excavation wall's stability, per OSHA requirements or engineering analysis.