Maintenance fundamentals — full outline

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.

1. 1.1Voltage, Current, Resistance, Power — and How They Show Up on the Floor 22 min8 terms
2. 1.2AC vs DC and Why the Plant Runs on AC 18 min9 terms
3. 1.3Three-Phase Power and Why It Wins for Motors 22 min9 terms
4. 1.4Single-Phase from 480 V, Two Hots, and Why It's Still One Sinusoid 18 min7 terms
5. 1.5Grounding, Bonding, and the System That Keeps You Alive 18 min8 terms

OSHA 1910.147, NFPA 70E, PPE categories, approach boundaries, the LOTO sequence that keeps you breathing, and the safety habits that separate veterans from victims.

1. 2.1Why Electrical Work Kills, and How LOTO Stops It 20 min8 terms
2. 2.2Arc Flash: What It Is and How NFPA 70E Keeps You Out of It 22 min10 terms
3. 2.3Mechanical and Thermal Hazards on a Production Line 18 min9 terms
4. 2.4PPE: What to Wear, Why, and the Habits That Stick 15 min8 terms

How to read a control print without getting lost. Symbols, wire numbering, ladder logic conventions, ISA/P&ID symbols, and the trick of reading a print backwards from the load.

1. 3.1How a Schematic Is Organized — And Why You Read Right to Left 18 min8 terms
2. 3.2Symbols You Must Recognize at a Glance 17 min9 terms
3. 3.3Latching Circuits, Seal-Ins, and Interlocks — The Logic Building Blocks 18 min7 terms
4. 3.4P&IDs and the ISA Symbol Set for Process Equipment 16 min8 terms

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.

1. 4.1How a Three-Phase Induction Motor Actually Works 22 min9 terms
2. 4.2Across-the-Line Starters and Their Overload Protection 18 min8 terms
3. 4.3Variable-Frequency Drives — The Heart of Every Extruder 25 min10 terms
4. 4.4Mechanical Relays vs Solid-State Relays — Pick the Right Tool 18 min9 terms
5. 4.5Barrel Heating Circuits — The Other Half of the Extruder Line 22 min9 terms

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.

1. 5.1Discrete Sensors: Proximity, Photoeye, and Limit Switches 18 min8 terms
2. 5.2Temperature: RTDs, Thermocouples, and Cold Junctions 20 min9 terms
3. 5.3The 4–20 mA Loop and Analog Signals 18 min7 terms
4. 5.4Melt Pressure, Load Cells, and the Sensors That Make the Line Possible 18 min9 terms

Compressed air systems, FRLs, directional control valves, cylinders, the basics of hydraulics for die lifts and clamping, troubleshooting leaks and pressure problems, and reading pneumatic schematics.

1. 6.1Compressed Air: The Plant's Fourth Utility 18 min8 terms
2. 6.2Cylinders, Valves, and How Pneumatic Circuits Work 18 min9 terms
3. 6.3Hydraulics on a Production Line 16 min8 terms
4. 6.4Pneumatic Troubleshooting in Practice 15 min6 terms

How a PLC scans, how I/O cards work, ladder logic vs structured text, addressing, force tables, online edits, and the basic diagnostic workflow for Allen-Bradley and Siemens systems running blown-film lines.

1. 7.1What a PLC Is and How It Scans 18 min9 terms
2. 7.2Ladder Logic — Programming in the Language of Electricians 20 min9 terms
3. 7.3Online Edits, Force Tables, and the PLC as Diagnostic Tool 17 min8 terms
4. 7.4PID Loops — The Math Behind Process Control 17 min9 terms

HMI fundamentals, EtherNet/IP and Profinet on the plant floor, Modbus, tag mapping, network topology, and how to troubleshoot communication problems on a Reifenhäuser-class system.

1. 8.1HMIs: The Operator's Window into the Process 16 min7 terms
2. 8.2EtherNet/IP, Profinet, and Modbus — The Three You'll Meet 20 min9 terms
3. 8.3Troubleshooting Network Communications 16 min8 terms

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.

1. 9.1The Troubleshooting Mindset and the Half-Split Method 18 min6 terms
2. 9.2Voltmeter Technique That Actually Works 22 min7 terms
3. 9.3Clamp Meters, Meggers, and Specialty Diagnostic Tools 17 min8 terms
4. 9.4Finding the Hard Stuff: Intermittents, Phantoms, and Weird Failures 17 min8 terms

PM scheduling, vibration analysis, oil analysis, thermography, ultrasonic detection, CMMS, certifications worth earning, and how to build a career in industrial maintenance.

1. 10.1Preventive Maintenance: The Schedule That Pays for Itself 16 min8 terms
2. 10.2Predictive Maintenance Techniques 18 min7 terms
3. 10.3Career Path: Certifications, Skills, and Advancement 16 min8 terms