The DHC motor protection relay is a reliable temperature monitoring relay for electric motors, offering compact design and enhanced safety features. It operates based on the closed-circuit principle and provides fail-safe reclosure prevention, ensuring the relay remains locked after a power failure. A motor restart is only possible after the temperature drops below the shutdown threshold and manual reset via the integrated front reset button.

Features:

• Very compact design
• High safety with:
- Fail-safe reclosure prevention
- Closed-circuit principle for detecting wire breaks

• Easy installation, even for multiple sensor resistors on a single relay
• Integrated reset button
• Permanent locking of the output relay at overtemperature (secured by a permanent memory)

Functionality:

• Normal Operation:
At normal temperature, the output contact (13-14) remains closed, keeping the control circuit active.

• Overtemperature:
When the motor winding reaches the shutdown threshold, contact 13-14 opens, interrupting the control circuit and locking the output relay. The red LED indicates the status.

• Reset:
The lock remains active until:
- The temperature drops below the shutdown threshold.
- The integrated reset button is manually pressed.

• Power Failure:
In case of a power failure, the relay remains locked in the triggered state. Interrupting the supply voltage does not reset the relay.


Safety Precautions:

• Installation and commissioning should only be performed by qualified personnel.
• Ensure the reset button is pressed only after the overtemperature condition has been resolved.

Included Items:

• DHC Motor Protection Relay

Applications:

• Protection of electric motors against overtemperature
• Monitoring of winding temperatures in industrial systems
• Ensuring motor safety with high operational reliability