NCCER Industrial Maintenance Mechanic

What is the primary purpose of preventive maintenance in an industrial setting?

• ATo repair equipment only after an unexpected breakdown occurs in typical plant service
• BTo schedule inspections, service to prevent unexpected failures
• CTo increase production speed by skipping routine lubrication
• DTo reduce maintenance staffing by eliminating PM work orders

What type of motor is most commonly used in industrial applications?

• ADC series motor for high starting torque only
• BUniversal motor for portable handheld tools
• CThree-phase AC induction motor for industrial loads
• DSingle-phase capacitor-start motor for residential HVAC

What does a hydraulic system use to transmit power?

• ACompressed air stored in receiver tanks
• BPressurized hydraulic fluid, usually oil
• CElectrical current through motor windings
• DSteam pressure from a boiler header

What is the function of a pneumatic FRL unit?

• ATo measure compressed-air flow rate only
• BTo filter, regulate,, lubricate air at the point of use
• CTo compress ambient air to system pressure on industrial equipment
• DTo store compressed air for peak demand

What is the purpose of a V-belt in a mechanical drive system?

• ATo clamp rotating shafts together rigidly
• BTo transmit power between pulleys using belt friction
• CTo measure shaft rotational speed accurately
• DTo supply automatic lubrication to sheave grooves per common shop practice

What is the correct viscosity grade of lubricant determined by?

• ABy the color printed on the oil container label
• BBy operating temperature, speed, load, and OEM specs
• CBy how long the equipment has been in service
• DBy the physical size of the bulk oil storage drum in most maintenance applications

What is the first step in troubleshooting a malfunctioning machine?

• AReplace every component that might be defective
• BGather symptom details and review maintenance history
• CCompletely disassemble the machine before testing
• DShut down the entire plant until the fault is found under rated load conditions

What does a PLC stand for in industrial automation?

• APower Line Controller for distribution panels
• BProgrammable Logic Controller for machine automation
• CPneumatic Lift Cylinder for vertical motion
• DPressure Level Calibrator for instrument loops in typical plant service

What is the purpose of lockout/tagout (LOTO) in industrial maintenance?

• ATo lock the maintenance shop when unattended
• BTo isolate and de-energize hazardous energy before work
• CTo tag inventory parts awaiting replacement
• DTo restrict visitor access to production areas during normal operation

What is the function of a hydraulic relief valve?

• ATo remove solid particles from hydraulic oil on industrial equipment
• BTo limit maximum pressure by bypassing excess flow
• CTo raise system pressure above pump capacity
• DTo measure hydraulic flow rate in gpm

What is the difference between a single-acting and double-acting hydraulic cylinder?

• AThey differ only in physical cylinder length
• BSingle-acting uses pressure on one side; double-acting on both
• CDouble-acting cylinders always stroke twice as fast
• DThere is no functional difference between the two types per common shop practice

What is the purpose of a motor starter?

• ATo rewind damaged motor stator windings
• BTo connect/disconnect power, provide overload protection
• CTo automatically lubricate motor bearings during run in most maintenance applications
• DTo measure and display motor shaft speed

What does the viscosity of a lubricant describe?

• AThe color added for leak-detection purposes
• BIts resistance to flow, or thickness, at a given temperature
• CThe temperature at which vapor ignites briefly
• DThe percentage of additive chemicals in the blend under rated load conditions

What is the function of a directional control valve in a hydraulic system?

• ATo remove water and particulates from the fluid
• BTo direct fluid flow to and from actuators
• CTo display system pressure on a gauge
• DTo store pressurized fluid for peak demand

What causes a motor to draw excessive current (overload)?

• AOperating continuously at rated nameplate load in typical plant service
• BMechanical overload, low voltage, single phasing, or bad bearings
• CRunning the motor at half synchronous speed
• DSupplying clean, balanced three-phase power

What is a pneumatic actuator?

• AA tank that stores compressed air at line pressure
• BA device that converts compressed air into motion
• CAn instrument that measures line air pressure
• DA filter that removes oil mist from supply air

What type of mechanical drive uses sprockets and a chain to transmit power?

• ABelt drive using friction in a V-groove sheave
• BGear drive with meshed teeth on parallel shafts
• CChain drive using roller chain and sprockets
• DFriction drive using smooth drums and tires

What is the purpose of a PLC input module?

• ATo display ladder logic on an HMI screen
• BTo receive field signals from sensors and switches
• CTo supply control power to the PLC rack
• DTo download revised programs from a laptop during normal operation

What is predictive maintenance?

• ARepairing equipment only after it has failed
• BUsing condition monitoring to predict needed maintenance
• CReplacing parts on a fixed calendar regardless of condition
• DDeferring all maintenance until a production shutdown

What is the function of a hydraulic pump?

• ATo store hydraulic fluid in the reservoir only
• BTo convert mechanical energy into hydraulic flow
• CTo maintain fluid temperature within limits
• DTo capture contaminants before they reach valves

What is the nameplate on a motor used for?

• ADecoration showing the manufacturer brand only
• BRated voltage, current, horsepower, speed,, frame data
• CThe purchase date and warranty expiration only
• DThe paint color code for touch-up in the field on industrial equipment

What is the purpose of an air dryer in a pneumatic system?

• ATo heat compressed air before it enters tools
• BTo remove moisture that can corrode piping and tools
• CTo raise line pressure above compressor output
• DTo filter solid particles larger than 40 microns per common shop practice

What is the proper way to check motor insulation resistance?

• AWith a voltmeter across the motor terminals in most maintenance applications
• BWith a megohmmeter between windings and ground
• CWith a handheld tachometer on the shaft
• DBy listening for abnormal running noise

What is the function of a flow control valve in a hydraulic system?

• ATo reverse flow direction to an actuator
• BTo regulate flow rate and control actuator speed
• CTo remove particulate contamination from oil under rated load conditions
• DTo store excess fluid during peak demand

What is the purpose of grease in a bearing?

• ATo increase bearing mass for stability
• BTo reduce friction, limit wear, and seal out dirt
• CTo raise bearing operating temperature for fit in typical plant service
• DTo make future bearing removal easier

What is the primary advantage of a gear drive over a belt drive?

• ALower initial cost than most belt drives
• BPositive drive with no slip and exact speed ratios
• CQuieter operation than chain or belt alternatives during normal operation
• DEasier field installation without alignment tools

What is a PLC output module used for?

• ATo receive analog signals from transmitters
• BTo send control signals to motors, valves, and lights
• CTo provide 24 VDC power to the processor
• DTo archive historical trend data on a server on industrial equipment

What is the half-split troubleshooting method?

• APhysically cutting the machine in half for access
• BTesting at the system midpoint to isolate the fault half
• CAssigning half the troubleshooting tasks to each tech per common shop practice
• DInspecting only half the components to save time

What is the purpose of a hydraulic accumulator?

• ATo filter solid contaminants from hydraulic oil in most maintenance applications
• BTo store pressurized fluid and supplement pump flow
• CTo cool hydraulic fluid through finned tubes
• DTo display system pressure on a panel gauge

What is a DC motor's main advantage over an AC motor?

• ALower purchase cost than comparable AC motors
• BPrecise speed control over a wide range
• CNo periodic maintenance of brushes or commutator
• DHigher efficiency than AC motors at all speeds

What is Pascal's Law?

• APressure in a confined fluid acts equally in all directions
• BForce equals mass multiplied by acceleration
• CHeated air rises because its density decreases
• DConductor resistance increases with temperature

What is the purpose of an overload relay in a motor circuit?

• ATo increase motor speed above synchronous RPM
• BTo protect against sustained overcurrent heating
• CTo clear dead short circuits in the supply lines
• DTo energize the motor contactor during start

What is the function of a pneumatic solenoid valve?

• ATo compress ambient air to working pressure in typical plant service
• BTo electrically shift airflow to pneumatic actuators
• CTo measure downstream pressure in the line
• DTo remove water vapor from the air supply

What is the NLGI consistency number for grease?

• AA color code printed on the grease tube
• BA stiffness scale from 000 (fluid) through 6 (block)
• CThe maximum continuous operating temperature
• DThe number of years before the grease expires during normal operation

What is the purpose of a coupling in a mechanical drive?

• ATo supply automatic lubrication to the shafts
• BTo connect shafts, transmit torque with some misalignment
• CTo reduce output speed between driver and driven on industrial equipment
• DTo measure torque transmitted through the shaft

What is ladder logic in PLC programming?

• AA programming language for portable step ladders per common shop practice
• BA graphical language resembling relay ladder diagrams
• CA procedure for climbing equipment safely
• DAn OSHA protocol for fixed ladder inspections