Maintenance fundamentals for the BJK Industries team.
The internal training portal for our maintenance crew. Work through the fundamentals — Electrical, LOTO, Motors, Instrumentation, Troubleshooting — on your own time. Use it as a reference when you need it, and as structured learning when you have the time. Let's get it dudes.
The 10-module curriculum
Modules unlock in order. Each lesson ends with a key-terms glossary. Each module ends with a 10-question check — pass at 80% to move on.
Electrical Fundamentals for Industrial Systems
Voltage, current, resistance, AC, DC, single-phase, three-phase, and the why behind 480 V hot-to-hot. Grounding and bonding without the legal padding.
Industrial Safety and LOTO
OSHA 1910.147, NFPA 70E, approach boundaries, the LOTO sequence that keeps you breathing, and the safety habits that separate veterans from victims. PPE specifics are covered separately when the team is ready for that level of detail.
The Multimeter — What It's Actually Doing
The meter is a tool, not magic. What's happening inside when you read volts, ohms, and amps; why true-RMS matters; why input impedance creates phantom voltage; and why ohms mode is really a tiny DC test the meter is running on the circuit.
Motors, Drives, Heating Circuits, and Control Relays
Three-phase induction motors, across-the-line starters, soft starters, VFDs (the engine of every extruder line), barrel-zone heating circuits with SSRs and contactors, and mechanical vs solid-state relays. The core daily knowledge for a blown-film maintenance crew.
Sensors and Instrumentation
Proximity, photoelectric, ultrasonic, RTD and thermocouple temperature, melt-pressure transducers, load cells, the 4–20 mA loop, and every sensor type a blown-film line uses to know what's going on.
Heating Control: SSRs, Thermocouples & Heater Bands
The science and the wiring behind every barrel zone on the floor: J-type thermocouples and the Seebeck effect, heater bands and their failure modes, solid-state relays and why they read open in ohms, phase-angle vs zero-cross firing, and tuning the PID loop that ties it all together.
Resin Conveying & Material Handling
How resin gets from the silo or gaylord to the extruder throat: vacuum pumps, receivers, filters, the continuous-run valves that keep PD pumps alive, airlocks for solids handling, and the PM schedule that prevents downtime.
Electrical Troubleshooting Methodology
The half-split method, signal tracing, true voltmeter technique, megger and clamp meter use, finding intermittents, and the systematic mindset that separates a maintenance pro from a parts-changer.
Pillar Corona Treaters & Web-Handling Interlocks
Why blown film needs corona treatment to take ink or glue, how a Pillar-style treater actually works (HF generator, ceramic roller, film as part of the load), and the speed-sensor interlocks that prevent a stopped web from destroying the equipment.
Batch Gravimetric Feeding Systems
How load-cell-based batch blenders dose virgin, regrind, color, and additive by weight; the hardware, the math, the calibration, and the failure modes that show up at the extruder throat.
How it works
Sign in with your account
Use your work email or Google. Your progress is saved so you can come back anytime.
Work the modules in order
Lessons unlock sequentially — same way you'd actually learn the plant.
Pass each module check at 80%
Ten questions per module. Misses show the right answer so it sticks.
Finish the final for your certificate
A 100-question comprehensive final. Pass it and download a certificate of completion for your file.
Pick up where you left off.
Sign in, open your next lesson, knock out a check. Five minutes or fifty — either way it counts.
Open the portal