Shop floor
120 questions the plant already has. Electricity, piping, pumps, switchgear, engines, air compressors, controls, and owner's-rep oversight. Each primer starts at the stuff and the push. It will ask you to commit before it names a wrong model — if you skip the checkpoint, it teaches on.
This is physics, not a license. The close is a record an owner's rep could demand, not a procedure you are asked to perform.
Electricity Mechanical piping Pumps Switchgear Engines Air compressors Network and controls Owner's-rep 18 questions
Electricity Charge, a closed loop, energy per charge, and a fault path that is not a magical sink.
What is the difference between voltage and current? Open Does electricity take the path of least resistance? Open What does grounding actually do? Open Why is there a ground wire if current returns on the neutral? Open Why don't birds get shocked on a power line? Open What is a short circuit? Open What does a GFCI actually sense? Open Why bond the neutral only at the service? Open What is a ground fault versus a short? Open Why do motors draw so much current when they start? Open What is a transformer doing? Open Why three-phase power? Open Why do buildings use AC instead of DC? Open What is power factor? Open What is an overload trip versus a short-circuit trip? Open Why can a fridge tingle on a concrete floor? Open What is lockout-tagout doing physically? Open How does a capacitor store energy? Open 16 questions
Mechanical piping Pressure is force on an area. Flow is volume per time. They are not the same word.
What is the difference between pressure and flow? Open What is water hammer? Open Why is the suction pipe often larger than the discharge? Open What does a check valve actually do? Open Why does pipe friction rise with flow? Open What is head in a piping system? Open Why do pipes burst when they freeze? Open Why is air in a hydronic system a problem? Open What is a pressure-reducing valve doing? Open Why slope a drain line? Open What is a steam trap doing? Open Why do hydronic systems need expansion tanks? Open How does a heat exchanger actually transfer heat? Open Why does a cold pipe sweat? Open What is flashing in condensate lines? Open What is a strainer actually protecting? Open 15 questions
Pumps A pump adds energy. It does not suck. Atmosphere pushes. Cavitation is boiling.
How does a centrifugal pump move liquid? Open Do pumps suck? Open What is cavitation? Open What is NPSH? Open Why do you prime a centrifugal pump? Open What is a pump curve? Open What happens if you dead-head a centrifugal pump? Open What changes if you speed a pump up? Open Centrifugal versus positive-displacement — what is actually different? Open Why a recirculation line? Open What is shutoff head? Open Why does a pump run but move no liquid? Open What is a mechanical seal doing? Open Why a strainer on the suction? Open Why is the suction line short, fat, and flooded when you can? Open 13 questions
Switchgear Opening a circuit means stretching and cooling an arc that wants to keep conducting.
What does a circuit breaker actually interrupt? Open Fuse versus breaker — what is the real difference? Open What is an electric arc and why won't it go out by itself? Open Why can't you rack out live switchgear? Open What is protective coordination? Open What is the difference between a disconnect and a breaker? Open What is an MCC? Open Why do breakers have an interrupting rating? Open What is arc flash, physically? Open What is a bus bar? Open Why interlocks on switchgear? Open What is a ground-fault relay looking at? Open What is an arc chute doing? Open 14 questions
Engines A heat engine: squeeze a mixture, burn it, let the expansion push, throw the leftovers out.
How does a four-stroke engine work? Open What is actually different between diesel and gasoline engines? Open What is compression ratio? Open What does octane actually measure? Open What is a turbocharger doing? Open Why does an engine need oil besides making it slippery? Open What is knock? Open Why a flywheel? Open What is the difference between torque and horsepower? Open What is a governor doing? Open What is the cooling system actually removing? Open Two-stroke versus four-stroke — what is actually different? Open Why glow plugs or intake heaters on diesel? Open What is the exhaust actually carrying away? Open 12 questions
Air compressors Work squeezed into a gas becomes heat. Water in the lines is that air cooling down.
How does an air compressor work? Open Why does compressed air get hot? Open Why is there water in the air lines? Open What is the receiver tank for? Open What is the difference between CFM and PSI? Open What is an unloader doing? Open Reciprocating versus rotary-screw — what is actually different? Open Why an aftercooler? Open Why a dryer on compressed air? Open What is duty cycle on a compressor? Open Why is oil in compressed air a problem? Open Why you should not use compressed air to blow off clothing Open 16 questions
Network and controls Measure, compare to what you wanted, move an actuator. Current loops survive long wire.
What is a PLC actually doing? Open What is PID control? Open Why 4-20mA instead of 0-10V? Open What is a ground loop in a signal cable? Open What is a setpoint? Open Why does turning the gain up make a loop oscillate? Open What is a VFD doing to a motor? Open What is the difference between discrete and analog? Open Relay versus contactor — what is actually different? Open Why shielded cable on analog? Open Why 24VDC for control power? Open What is an interlock in a control system? Open Fail-open versus fail-closed — what is being failed? Open What is deadband? Open What is a watchdog timer? Open Why a separate analog common? Open 16 questions
Owner's-rep You do not swing the wrench. You decide whether the work happened — from a record, not a feeling.
A CT landed backwards — what still looks correct? Open Jack screws left in under a grouted baseplate. Where does the machine's weight go? Open Fuel valve slams shut on a synchronized unit. What does the shaft do over the next ten seconds? Open A loop check passed. What has that not proved? Open Same torque on every anchor. Same clamp load? Open A windy hundred-degree pour day — does the concrete get stronger faster? Open Align the coupling to dead-zero cold. Where is it when the machine is hot? Open A 4/0 in a packed tray versus in free air — same ampacity? Open The cable made it through the pull. What damage would you still not see? Open Bolt a pipe solid at both ends. What does the steel do when it heats? Open A generator fault. Does the current stay high until the breaker opens? Open Why would you deliberately limit ground-fault current on a stator? Open What does a differential relay actually compare? Open A hold point versus a witness point — whose signature gates what? Open Raising excitation — what actually goes up? Open What is a one-line diagram actually showing you? Open