--- title: "Electrical Components" url: "https://www.imspares.com/categories/electrical/" --- # Electrical Components Electrical systems and components for injection molding machines including heaters, thermocouples, servo motors, and controllers. ## Parts of the electrical system 1. **Safety gate switch**: Limit switch pressed by the safety gate as it closes. Until it reports the gate closed, the controller will not close the mold. Part numbers: EC-SF-01. 2. **Proximity sensor**: Inductive sensor that detects a steel target on the moving platen without touching it, for platen and ejector positions. Part numbers: EC-SF-03. 3. **Controller boards**: The CPU board runs the machine program. I/O, drive interface and power supply boards connect it to the switches, valves, heaters and servo drive. 4. **Capacitors**: Electrolytic and film capacitors in the drives and power supplies smooth the DC voltage and filter electrical noise. Electrolytic capacitors wear out with heat and age. 5. **Heater bands**: Ceramic heater bands clamped around the barrel melt the plastic. The controller switches each zone on and off to hold its set temperature. Part numbers: EC-HT-01. 6. **Thermocouples**: Temperature sensors fitted into the barrel between the bands. The controller reads them to switch each heater zone. Part numbers: EC-HT-02. 7. **Servo motor**: Drives the hydraulic pump on servo-hydraulic machines, powered and controlled by a servo drive in the cabinet. Part numbers: EC-GEP-01. ## Circuit Boards & Controllers PLC controllers, driver boards, and electronic control units - [EC-CBC-06 Controller Board — I/O Module](https://www.imspares.com/parts/ec-cbc-06/): Replacement I/O controller board for injection molding machine electrical cabinet. - [EC-CBC-12 Controller Board — Main CPU Board](https://www.imspares.com/parts/ec-cbc-12/): Main CPU controller board for injection molding machine control system. - [EC-CBC-13 Controller Board — Drive Interface](https://www.imspares.com/parts/ec-cbc-13/): Drive interface controller board for injection molding machine servo/inverter systems. - [EC-CBC-14 Controller Board — Power Supply Board](https://www.imspares.com/parts/ec-cbc-14/): Power supply board for injection molding machine electrical cabinet. ### Parts of the control system 1. **Operator panel**: Screen and keys where the operator sets and watches the machine. It talks to the CPU board over a cable. 2. **Main CPU board**: Runs the machine program: it reads the inputs, steps through the cycle and sends commands to the valves, heaters and drives. Part numbers: EC-CBC-12. 3. **I/O modules**: Connect the CPU to the machine: inputs from switches and sensors, outputs to valve solenoids, contactors and heater relays. Part numbers: EC-CBC-06. 4. **Drive interface board**: Passes speed and pressure commands from the CPU to the servo drive or inverter and reads back its status. Part numbers: EC-CBC-13. 5. **Power supply board**: Turns the cabinet supply into the regulated DC voltages that the boards, sensors and valve coils run on. Part numbers: EC-CBC-14. 6. **Servo drive**: Powers and controls the servo motor that drives the hydraulic pump, following the commands from the drive interface board. 7. **Terminal blocks**: The wiring from switches, sensors, valves and heaters lands here and runs through the cable duct to the I/O modules. ## Connectors & Cables Industrial connectors, cable assemblies, and wiring harnesses - [EC-CE-01 Electrolytic Capacitor](https://www.imspares.com/parts/ec-ce-01/): High-capacity electrolytic capacitor for injection molding machine servo drives and inverters. - [EC-CE-02 Film Capacitor / Filter Capacitor](https://www.imspares.com/parts/ec-ce-02/): Film capacitor for injection molding machine drive filtering and power conditioning. ### Capacitors in a servo drive 1. **Mains input terminals**: Where the three-phase supply enters the drive. 2. **Film capacitors**: Filter capacitors across the incoming lines. They suppress electrical noise (EMI) that the drive would otherwise send into the supply. Part numbers: EC-CE-02. 3. **Rectifier**: Turns the incoming AC into DC for the DC bus. 4. **DC bus capacitors**: Electrolytic capacitors that store energy on the DC bus and smooth its voltage. They wear out with heat and age, so they are replaced in drive repairs. Part numbers: EC-CE-01. 5. **Power module**: Switches the DC bus voltage into the variable AC that drives the servo motor. 6. **Can and sleeve**: The aluminium can holds the wound foil. The plastic sleeve insulates it and carries the rating and the polarity stripe. Part numbers: EC-CE-01. 7. **Safety vent**: Opens under internal pressure when the capacitor fails, instead of letting it burst. A bulging vent means the capacitor needs replacing. Part numbers: EC-CE-01. 8. **Screw terminals**: Bolt the capacitor to the DC bus bars. Part numbers: EC-CE-01. ## Servo Motors & Drives AC servo motors, servo drives, and encoder systems - [EC-GEP-01 AC Servo Motor](https://www.imspares.com/parts/ec-gep-01/): High-performance AC servo motor for energy-saving injection molding machine hydraulic systems. ### Parts of an AC servo motor 1. **Encoder**: Measures the shaft position and speed. The servo drive reads it to control the motor precisely. Part numbers: EC-GEP-01. 2. **Rear bearing**: Supports the rear end of the shaft. Part numbers: EC-GEP-01. 3. **Power and encoder connectors**: The power cable to the stator and the signal cable from the encoder both run to the servo drive. Part numbers: EC-GEP-01. 4. **Stator windings**: Copper coils in a laminated steel stack. The drive feeds them current to make a rotating magnetic field. Part numbers: EC-GEP-01. 5. **Rotor with magnets**: Permanent magnets on the rotor follow the stator’s field and turn the shaft. Part numbers: EC-GEP-01. 6. **Front bearing**: Carries the shaft and the load from the coupling. Part numbers: EC-GEP-01. 7. **Mounting flange**: Bolts the motor to the pump bell housing; the spigot centres the shaft. Part numbers: EC-GEP-01. 8. **Shaft**: Output shaft with a keyway; it drives the pump through the flexible coupling. Part numbers: EC-GEP-01. ## Heaters Ceramic heater bands, mica heaters, and nozzle heaters for barrel heating - [EC-HT-01 Ceramic Heater Band](https://www.imspares.com/parts/ec-ht-01/): Full-enclosed ceramic heater band for injection molding machine barrel and nozzle heating zones. - [EC-HT-02 Thermocouple Sensor](https://www.imspares.com/parts/ec-ht-02/): Precision thermocouple temperature sensor for injection molding machine barrel temperature measurement. ### Parts of barrel heating 1. **Barrel**: The steel barrel the screw turns in. Its heating zones run from the feed throat to the nozzle. 2. **Nozzle heater**: A small band on the nozzle keeps the melt at temperature between shots. Part numbers: EC-HT-01. 3. **Ceramic heater bands**: Each band heats one zone of the barrel. The controller switches it on and off to hold the set temperature. Part numbers: EC-HT-01. 4. **Terminal box**: Covers the band’s power terminals, where the heater cable connects. Part numbers: EC-HT-01. 5. **Ceramic blocks and coil**: Inside the steel shell (cut away here), a resistance coil runs through ceramic blocks that hold it in place and insulate it. Part numbers: EC-HT-01. 6. **Clamp bolt**: Tightens the band against the barrel so the heat passes into it. A band removal tool helps free a band stuck to the barrel. Part numbers: EC-HT-01. 7. **Thermocouples**: Sensors set into the barrel wall between the bands. The controller reads each one to switch its zone. Part numbers: EC-HT-02. ## Safety Components Safety switches, relays, interlocks, and emergency stop components - [EC-SF-01 Safety Switch / Limit Switch](https://www.imspares.com/parts/ec-sf-01/): Safety and limit switch for injection molding machine guard door and travel detection. - [EC-SF-03 Proximity Sensor / Position Sensor](https://www.imspares.com/parts/ec-sf-03/): Inductive proximity sensor for injection molding machine position detection. ### Safety switches and position sensors 1. **Safety gate**: Sliding guard over the mold area. While it is open, the machine must not close the mold. 2. **Gate cam**: Ramp on the gate that pushes the switch roller as the gate closes. 3. **Roller lever**: The lever and roller that the cam presses; the lever works the switch contacts. Part numbers: EC-SF-01. 4. **Limit switch**: Tells the controller that the gate is closed. Without that signal the mold will not close. Part numbers: EC-SF-01. 5. **Proximity sensor**: Inductive sensor that switches when steel comes within range, without contact. Used for platen and ejector positions and mold protection. Part numbers: EC-SF-03. 6. **Lock nuts**: Hold the sensor in its bracket and set the gap to the target, which must stay within the sensor’s sensing distance. Part numbers: EC-SF-03. 7. **Target**: Steel plate on the moving platen that the sensor detects as the platen passes.