Wago 847-836 Test Disconnect Terminal Block with Automatic Current Transformer Short-Circuiting

The Wago 847-836 is a specialized test disconnect terminal block engineered specifically for current transformer (CT) circuits. This component provides a secure and efficient method for managing secondary circuits, featuring an integrated automatic short-circuiting mechanism that activates during disconnection. By ensuring the secondary side of the current transformer is safely short-circuited before the circuit is opened, this terminal block prevents dangerous high-voltage build-up, thereby protecting both personnel and equipment during maintenance and testing procedures.

Advantages

The primary benefit of this terminal block is the inherent safety provided by its automatic short-circuiting function, which eliminates the risk of open-circuit conditions that can damage current transformers. Its design simplifies the testing and calibration process by allowing for quick and reliable disconnection of measurement devices without the need for manual bridging. The robust construction ensures long-term reliability in demanding industrial environments, while the intuitive design reduces the potential for human error during complex electrical maintenance tasks.

Suitable for

• Current transformer secondary circuit management
• Industrial electrical testing and measurement
• Calibration of energy meters and protection relays
• Maintenance of power distribution systems

This terminal block may not be suitable for applications involving high-voltage primary circuits or non-standard current transformer configurations that require specific manual switching sequences not supported by the automatic mechanism. It is also not intended for use in environments exceeding the specified thermal or electrical ratings.

Key specifications

• Function: Test disconnect with automatic short-circuiting
• Application: Current transformer secondary circuits
• Design: Integrated safety mechanism
• Mounting: DIN-rail compatible

To use the Wago 847-836, mount the terminal block onto a standard DIN-rail within the control cabinet. Connect the current transformer secondary leads to the designated terminals. During routine testing or maintenance, the disconnect mechanism allows for the safe isolation of the measurement equipment. The automatic short-circuiting feature engages as the circuit is opened, ensuring the transformer remains protected throughout the entire operation.

What to consider before purchase

• Verify that the current transformer secondary rating matches the terminal block specifications
• Ensure sufficient space is available on the DIN-rail for installation
• Confirm compatibility with existing measurement and protection equipment

Usage recommendations

Always verify that the short-circuiting mechanism is fully functional before performing any maintenance on the secondary circuit. Ensure that all connections are tightened to the manufacturer's specified torque to prevent overheating and contact resistance.