Current transformer Rittal SV 9677.865 — 250 A output, conductor Ø 2.5–4 mm, black

Rittal SV 9677.865 is a through-type current transformer designed for inductive measurement of current flow. It delivers a nominal output current of 250 A and accepts conductors with diameters from 2.5 to 4 mm. Housed in a black enclosure, this compact transformer is intended for use in switchgear, control cabinets and industrial installations where reliable current sensing, isolation and interface to monitoring or protection equipment are required.

Advantages

The through-type design allows easy installation without disconnecting the primary conductor. Its 250 A nominal output supports integration with standard protection relays and meters, and the specified conductor diameter range ensures compatibility with common feeder and sensor cables. The black housing provides a neutral appearance and mechanical protection for the magnetic core and secondary winding.

Suitable for

• Current monitoring and metering in switchgear and distribution panels
• Integration with protection relays and measurement instruments
• Applications requiring electrical isolation between primary conductor and secondary measurement circuit
• Industrial control cabinets and machine panels with conductors Ø 2.5–4 mm

When it may not be suitable

This transformer is intended for inductive measurement and is not a primary power device; it must be used with appropriate secondary circuits and protective equipment. It is not suitable where conductors exceed the specified diameter range or where a different transformation ratio or physical mounting style is required.

Key specifications

• Type: Through-type (window) current transformer
• Nominal secondary output: 250 A
• Primary conductor diameter compatibility: 2.5–4 mm
• Colour: Black housing
• Function: Inductive current measurement, isolation for protection and metering

How to use

Install the transformer by passing the live conductor through the window, ensuring the conductor fits within the 2.5–4 mm diameter range. Secure the unit in the control cabinet or on the mounting surface per the enclosure design and local installation rules. Connect the secondary output to the measurement or protection device using appropriately rated wiring and ensure correct polarity. Verify that the secondary circuit is never left open under load and that the installation complies with applicable electrical safety standards.

What to consider before purchase

• Confirm conductor diameter is within 2.5–4 mm for a secure fit and accurate measurement
• Ensure the 250 A nominal output matches the input range of your meter or relay
• Check physical mounting and available space in the switchgear or cabinet
• Verify compatibility with required safety and installation standards

Usage recommendations

Use the Rittal SV 9677.865 with properly rated secondary wiring and protective devices. Avoid opening the secondary circuit when the primary is energized, and perform commissioning checks with suitable instruments to confirm correct polarity and expected output before putting the system into service.