Instruction Manual

1. Introduction

This manual provides essential information for the safe and effective installation, operation, and maintenance of the GGHLT LRD16 LR-D16 Thermal Overload Relay. This device is designed to provide reliable thermal overload protection for electric motors, preventing damage due to excessive current draw. It is rated for a current range of 9 to 13 Amperes and falls under Class 10A protection.

2. Product Overview

Figure 1: GGHLT LRD16 Thermal Overload Relay
This image displays the GGHLT LRD16 thermal overload relay. Key features visible include:

• Top Terminals: Three copper-colored terminals for connection to the motor's power supply.
• Current Adjustment Dial: A clear dial marked "LRD 16" with a range from 9 to 13 Amperes, allowing precise setting of the overload trip current. The current setting is currently at 11.5A.
• Control Buttons: A blue "RESET" button and a red "STOP" button are located on the front face for manual control.
• Auxiliary Contacts: Terminals labeled "97 NO" (Normally Open) and "98 NO" (Normally Open) for auxiliary contacts.
• Normally Closed Contacts: Terminals labeled "95 NC" (Normally Closed) and "96 NC" (Normally Closed) for auxiliary contacts.
• Power Output Terminals: Terminals labeled "2T1", "4T2", and "6T3" at the bottom for connection to the motor.

3. Setup and Installation

Before installation, ensure the main power supply is disconnected to prevent electrical shock. This device should be installed by a qualified electrician in accordance with local and national electrical codes.

1. Mounting: Mount the thermal overload relay directly onto a compatible contactor or a DIN rail, ensuring a secure fit.
2. Power Connections: Connect the main power circuit to the top terminals of the relay. Connect the motor leads to the bottom terminals (2T1, 4T2, 6T3) as shown in Figure 1.
3. Control Circuit Wiring: Wire the auxiliary contacts (97 NO, 98 NO, 95 NC, 96 NC) into the motor control circuit as required for start/stop functions, signaling, or interlocking. Typically, the 95 NC and 96 NC contacts are used in series with the contactor coil to interrupt power upon overload.
4. Current Setting: Adjust the current setting dial (visible in Figure 1) to match the full load current (FLA) of the motor being protected. The setting should be within the 9-13 A range of the relay.

4. Operating Instructions

The LRD16 thermal overload relay operates automatically to protect the motor from sustained overcurrents. Manual intervention is typically required only after an overload trip.

• Normal Operation: When the motor operates within its rated current, the relay allows current to pass through without interruption.
• Overload Trip: If the motor draws current exceeding the set value for a prolonged period, the thermal elements within the relay heat up and cause the internal mechanism to trip. This opens the normally closed (NC) contacts (95-96) in the control circuit, de-energizing the motor contactor and stopping the motor.
• Resetting the Relay: After an overload trip, allow the relay to cool down for a few minutes. Then, press the blue RESET button (see Figure 1) to reset the tripping mechanism. The motor can then be restarted.
• Stopping the Motor: The red STOP button (see Figure 1) can be used to manually trip the relay, opening the control circuit and stopping the motor. This is useful for testing or emergency shutdown.

5. Maintenance

The LRD16 thermal overload relay is designed for minimal maintenance. Regular inspection is recommended to ensure optimal performance.

• Visual Inspection: Periodically inspect the relay for any signs of physical damage, discoloration, or loose connections.
• Cleaning: Keep the relay free from dust and debris. Use a dry, soft cloth for cleaning. Do not use solvents or abrasive cleaners.
• Functionality Test: Periodically test the trip function by manually pressing the STOP button to ensure the control circuit opens.

6. Troubleshooting

7. Specifications

8. Warranty and Support

For warranty information and technical support, please contact the manufacturer, GGHLT, or your authorized distributor. Keep your purchase receipt for warranty claims. Specific warranty terms and conditions may vary by region and purchase date.

For further assistance, refer to the contact information provided with your product packaging or visit the official GGHLT website.