Current transformer Rittal 9677.340 — nominal current 1250 A, output voltage 690 V, colour White

Rittal 9677.340 is a current transformer designed for integration into low- and medium-voltage distribution and switching systems. The device provides a nominal current handling of 1250 A and is configured for a three-pole arrangement suitable for busbar systems with 185 mm centre-to-centre spacing. Finished in white, it is intended for bolted connections and reliable current measurement or distribution tasks within switchgear assemblies and fuse busbar installations. The transformer supports systems with an output voltage rating of 690 V and is manufactured for stable mechanical mounting and electrical continuity in industrial and commercial switchgear.

Advantages

The unit offers a compact three-pole design that fits standard 185 mm centre-to-centre bar spacing and allows direct bolted connections for secure mechanical and electrical contact. Its 1250 A nominal current rating and 690 V output voltage make it suitable for typical distribution and switching roles, while the white finish allows easy visual integration into existing switchgear. The product is built to match the mechanical and electrical demands of busbar-mounted fuse and switching assemblies, providing predictable current handling and simplified installation.

Suitable for (tasks / use cases)

• Integration into switchgear and distribution boards where a 1250 A nominal current is required
• Busbar systems with 185 mm centre-to-centre spacing
• Bolted connections in fuse busbar and NH-fuse switching arrangements
• Industrial and commercial electrical distribution and power switching applications

When it may not be suitable

This transformer is not intended for use outside of its rated nominal current of 1250 A or for systems with different centre-to-centre bar spacing. It should not be used as a standalone measurement device in applications that require isolated secondary measurement outputs or where additional voltage transformation is necessary beyond the specified 690 V rating. Applications that demand different mounting arrangements, non-bolted connections, or substantially different electrical ratings will require a different model.

Key specifications

• Nominal current: 1250 A
• Output voltage rating: 690 V
• Poles: 3-pole configuration
• Designed for busbar centre-to-centre spacing: 185 mm
• Connection type: bolted connections for mechanical and electrical continuity
• Colour/finish: white

How to use

Mount the current transformer in the switchgear assembly aligning the three poles to the busbar centres at 185 mm spacing. Secure the unit using the specified bolted connections to ensure firm mechanical fixing and reliable electrical contact. Verify that the system voltage and current requirements match the transformer's 690 V output rating and 1250 A nominal current capacity before energizing. Ensure all safety and lockout procedures are followed during installation, and perform continuity and insulation checks after mounting and before putting the circuit into service.

What to consider before purchase

• Confirm busbar centre-to-centre spacing is 185 mm to match the transformer configuration
• Verify the application requires a nominal current rating of 1250 A and an output voltage of 690 V
• Ensure the installation accepts bolted connection types and the physical dimensions fit the intended switchgear
• Check compatibility with the specific fuse busbar or NH-fuse arrangement in the system

Usage recommendations

Use the transformer only within its rated electrical and mechanical parameters. Install with proper torque on bolted connections, follow manufacturer mounting instructions, and schedule regular inspections for secure connections and proper operation in switchgear environments.