Heschen LW28-32/B303.3 Universal Rotary Cam Selector Power Switch Instruction Manual

1. Overview

This manual provides detailed instructions for the installation, operation, and maintenance of the Heschen LW28-32/B303.3 Universal Rotary Cam Selector Power Switch. This switch is designed for electrical wiring applications, including power switching, asynchronous motor start-up, reversing, and speed control circuits. It features a momentary action with three positions and twelve screw terminals.

Figure 1: Heschen LW28-32/B303.3 Rotary Cam Selector Switch, showing the main body, terminals, and label with model number and CE marking.

2. Safety Information

WARNING: Electrical installation should only be performed by qualified personnel. Failure to follow these instructions can result in electric shock, fire, or serious injury.

• Always disconnect power before installing, wiring, or servicing the switch.
• Ensure all wiring complies with local and national electrical codes.
• Verify the voltage and current ratings of the switch are suitable for your application.
• Do not operate the switch if it is damaged or appears to be malfunctioning.
• Wear appropriate personal protective equipment (PPE) during installation and maintenance.

3. Product Features

The Heschen LW28-32/B303.3 Rotary Cam Selector Switch offers robust performance and versatile application:

• Operation Mode: (ON)-Off-(ON) Momentary Type, providing a spring-return action to the 'Off' position.
• Pole Numbers: 3 Pole design for multi-phase control.
• Current Rating: 32 Amps (Ith) for reliable power handling.
• Operating Voltage: 660 Volts (Ui) maximum.
• Terminals: 12 screw terminals for secure and straightforward wiring.
• Positions: 3 positions (1)-0-(2) for flexible control.
• Material: Durable plastic external material.
• Panel Thickness: Designed to fit panels up to 1.3 cm (approximately 0.51 inches) thick.
• International Protection Rating: IP64, indicating protection against dust ingress and splashing water.

4. Specifications

Refer to the table below for detailed technical specifications of the LW28-32/B303.3 switch.

Figure 2: Close-up view of the product label showing key electrical specifications and certifications.

Figure 3: Dimensional drawing of the Heschen LW28-32/B303.3 switch, indicating overall length, width, and height in inches and millimeters.

5. Setup & Installation

Follow these steps for proper installation of the rotary cam selector switch:

1. Prepare Panel: Cut a suitable mounting hole in your control panel. The switch is designed for panels up to 1.3 cm thick. Refer to the dimensions in Figure 3 for precise cutout requirements.
2. Disassemble Switch: Separate the front plate and handle assembly from the main switch body. This typically involves unscrewing the mounting screws.
3. Mount Switch Body: Insert the main switch body through the panel cutout from the rear.
4. Secure Front Plate: Place the front plate (with the '1-0-2' markings) over the switch shaft from the front of the panel.
5. Install Handle: Attach the rotary handle to the switch shaft, ensuring it aligns correctly with the '0' position when the switch is in its central state. Secure with the provided screw.
6. Tighten Mounting Screws: Use the provided screws to firmly secure the switch assembly to the panel.
7. Wiring: Connect your electrical circuits to the 12 screw terminals. Refer to the wiring diagram (Figure 5) for correct terminal assignments. Ensure all connections are tight and secure.

Figure 4: Exploded view illustrating the components and assembly sequence for panel mounting the rotary cam selector switch.

Figure 5: Detailed wiring diagram showing terminal numbering (1-12) and contact configurations for positions 0, 1, and 2. 'X' indicates an open contact, '||' indicates a closed contact.

6. Operating Instructions

The Heschen LW28-32/B303.3 is a 3-position momentary rotary cam selector switch. This means the handle will automatically return to the central '0' (Off) position when released from either position '1' or position '2'.

• Position '0' (Off): This is the default central position. In this state, all contacts are open as per the wiring diagram (Figure 5).
• Position '1' (Momentary ON): Rotate the handle counter-clockwise to position '1'. The switch will engage the contacts configured for position '1'. Upon release, the handle will automatically return to position '0'.
• Position '2' (Momentary ON): Rotate the handle clockwise to position '2'. The switch will engage the contacts configured for position '2'. Upon release, the handle will automatically return to position '0'.

This momentary action is ideal for applications requiring temporary circuit activation, such as motor jogging, pulse commands, or selecting between two temporary states.

Figure 6: Diagram illustrating the automatic return mechanism of the rotary switch handle, showing it springs back to the '0' position from '1' or '2'.

7. Maintenance

The Heschen LW28-32/B303.3 switch is designed for durability and requires minimal maintenance. However, periodic checks can ensure optimal performance and longevity:

• Visual Inspection: Regularly inspect the switch for any signs of physical damage, wear, or discoloration.
• Terminal Connections: Periodically check all screw terminals to ensure they remain tight and free from corrosion. Loose connections can lead to overheating and malfunction.
• Cleaning: If necessary, clean the external surfaces of the switch with a dry, soft cloth. Avoid using abrasive cleaners or solvents that could damage the plastic material.
• Environmental Conditions: Ensure the operating environment remains within the specified temperature and humidity ranges to prevent premature wear. The IP64 rating provides protection against dust and splashing water, but avoid direct exposure to high-pressure water jets or prolonged immersion.

Note: Do not attempt to disassemble the internal components of the switch beyond what is necessary for installation. There are no user-serviceable parts inside.

8. Troubleshooting

If you encounter issues with your Heschen LW28-32/B303.3 switch, consider the following common troubleshooting steps:

• Switch Not Activating Circuit:
  • Verify that power is supplied to the circuit.
  • Check all wiring connections for tightness and correct terminal assignment according to Figure 5.
  • Ensure the switch handle is fully rotated to position '1' or '2' and held there for momentary action.
  • Inspect for any visible damage to the switch or wiring.
• Handle Not Returning to '0' Position:
  • Check for any obstructions preventing the handle from returning.
  • Ensure the switch is correctly mounted and not binding against the panel.
  • If the spring mechanism is faulty, the switch may need replacement.
• Overheating:
  • Confirm that the current draw of the connected load does not exceed the switch's rated current (32A Ith, 30A AC-23A, 22A AC-3, 11A AC-4).
  • Check for loose or corroded terminal connections, which can cause resistance and heat.

If the problem persists after performing these checks, consult a qualified electrician or contact Heschen customer support.

9. Warranty and Support

For warranty information or technical support regarding your Heschen LW28-32/B303.3 Universal Rotary Cam Selector Power Switch, please refer to the documentation provided at the time of purchase or visit the official Heschen website. Keep your purchase receipt as proof of purchase for any warranty claims.

For further assistance, you may contact Heschen customer service through their official channels.