Preventive Maintenance & Lubrication Flashcards
6 cards from real Amazon Maintenance Technician practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Preventive Maintenance & Lubrication flashcards as text
Which technique uses infrared thermography during PM inspections to identify problems in electrical panels?
Answer: Thermal imaging
Thermal imaging cameras detect abnormal heat signatures in electrical connections, identifying loose connections or overloaded components before failure.
What is the correct procedure when mixing two different grease types during a PM?
Answer: Avoid mixing; if switching, purge old grease completely before applying the new type
Different grease thickener systems (lithium, calcium, polyurea) can be chemically incompatible, causing softening or hardening that leads to bearing failure.
What is the purpose of vibration analysis in a predictive/preventive maintenance program for motors?
Answer: Detect imbalance, misalignment, bearing wear, or looseness before catastrophic failure
Vibration signatures identify mechanical faults such as unbalance, misalignment, and bearing defects, allowing scheduled repair before unplanned breakdown.
A conveyor drive chain shows elongation (stretch) during a PM inspection. What action should be taken?
Answer: Measure elongation against manufacturer's wear limit; replace if it exceeds 3% elongation
Chain elongation of 3% or more indicates significant pin and bushing wear; continued use risks sprocket damage and sudden chain failure.
What is the primary difference between time-based and condition-based maintenance strategies?
Answer: Time-based replaces parts on a fixed schedule; condition-based replaces them when monitoring data indicates degradation
Time-based PM replaces parts at fixed intervals regardless of condition; condition-based maintenance (CBM) uses real-time data to trigger maintenance only when needed.
When torquing fasteners during reassembly after PM work, why is a torque wrench required instead of hand-tightening?
Answer: Torque wrenches prevent over-tightening that can strip threads or under-tightening that causes loosening and vibration fatigue
Proper torque ensures correct clamping load; over-tightening can yield fasteners and under-tightening allows joints to loosen under vibration.