AIT 125 - Electrical Systems I

1. Read and interpret electrical motor control and programmable logic controller system schematics, including identifying schematic symbols, signal flow, and operation of the components and system.
2. Adjust and test limit switches, pressure switches, float switches, and electronic proximity sensors.
3. Use a multimeter to measure voltage, current, and resistance in an electrical circuit to verify system operation and power levels.
4. Select, install, and test: fuses, circuit breakers, electrical relay control components in a control system, and electro-fluid power components and circuits.
5. Troubleshoot a solenoid-operated fluid power relay control circuit.

1. Test and replace transformers.

1. Reading, Interpreting Electrical Motor Control and Programmable Controller System Schematics (e.g. Identifying Schematic Symbols, Signal Flow, and Operation of the Components and System)
   1. Electrical components identification (given their NEC/ISO schematic symbol)
   2. Interpreting electrical control and power line types on a schematic
   3. Interpreting the operation of a basic electrical power and control circuits (given a schematic)
   4. Following signal flow on an electrical control or power schematic
   5. Interpreting control schematics (given a ladder logic diagram)
   6. Interpreting power diagrams associated with a PLC and all related input/output devices
2. Adjusting, Testing Limit Switches, Pressure Switches, Float switches, and Electronic Proximity Sensors
   1. Adjusting/ testing the trip point of:
      1. Limit switch, float switch, and pressure switch
      2. Capacitive sensor, inductive sensor, photoelectric sensor, Hall Effect sensor, fiber optic, magnetic reed sensor, and light curtain switches
   2. Operation of limit, float, and pressure switches
   3. Operation of capacitive sensors, inductive sensors, photoelectric sensors, Hall Effect sensors, fiber optic sensors, and magnetic reed sensors
3. Using Multimeter to Measure Voltage, Current, and Resistance in an Electrical Circuit to Verify System Operation and Power Levels
   1. Multimeter to measure:
      1. Incoming voltage and current to an electrical circuit
      2. Voltage and current in an electrical circuit
      3. Resistance in an electrical circuit
   2. Multimeter to perform a continuity check in an electrical circuit
   3. Concepts of resistance, voltage, current, and power
   4. Using a clamp on amp meter
   5. Application of a multimeter to measure continuity, resistance, voltage, and current
   6. Ohm’s law definition (to determine power flow in electrical circuits)
   7. Calculating power in an electrical circuit (given current and voltage)
   8. Operation of parallel and series electrical circuits
4. Selecting, Installing, and Testing Fuses and Circuit Breakers
   1. Size fuses and circuit breakers (in accordance with NEC requirements for a given power draw in an electrical circuit with consideration to ampacity of wiring in that circuit)
   2. Installing fuses and circuit breakers in electrical circuits
   3. Procedure to test fuses
   4. Inspecting circuit breakers (to determine if tripped)
   5. Resetting circuit breakers
   6. Operation of fuses, circuit breakers, and GFCI’s
   7. Fuse types identification and their use
5. Installing, Testing Electrical Relay Control Components in a Control System
   1. Operation of control transformers, pushbutton switches, selector switches, control relays, magnetic motor starters, overloads, indicator lamps, electronic sensors, drum switches, solenoid operated fluid power valves, capacitors, resistors, and disconnect switches
   2. Operation of basic single direction and reversing direction motor control circuits with interlocks and sensors
   3. Installing/connecting NEMA/IEC relay control components in a control circuit (given a wiring diagram or schematic)
   4. Installing wiring between components:
      1. Control cabinet using raceways
      2. Located in different enclosures via conduit
   5. Replacing failed relay contacts and coils
6. Installing, Testing Electro-Fluid Power Components and Circuits
   1. Operation of solenoid-operated hydraulic and pneumatic valves
   2. Operation of relay-controlled sequence fluid power circuits
   3. Installing/connecting solenoid-operated hydraulic and pneumatic valves in a control circuit (given a wiring diagram or schematic)
   4. Manual overrides to test operation and describe the potential negative effects or consequences
7. Troubleshooting a Solenoid-Operated Fluid Power Relay Control Circuit
   1. Types of failures of solenoid-operated valves
   2. Solenoid-operated hydraulic and pneumatic directional control valves troubleshooting (using in-circuit tests)
   3. Systematic methodologies to troubleshoot electro-fluid power relay control circuits
8. Testing, Replacing Transformers
   1. Transformer ratio definition
   2. Types and configurations of transformers and their application
   3. Rating of a transformer
   4. Connection point and taps for each type of transformer
   5. Testing a transformer
   6. Disconnecting/reconnecting primary and secondary transformers
   7. Replacing primary and secondary transformers