Current transformer Rittal SV 9677.810 150 A, conductor diameter 2.5–4 mm, black

Rittal SV 9677.810 is a fixed current transformer designed to convert high primary currents into a manageable secondary signal for measurement and protection circuits in electrical panels and switchgear. The unit provides a nominal secondary current of 150 A and is intended for use with single conductors having diameters between 2.5 and 4 mm. Finished in black, this compact transformer is suitable for inductive measurement of current flow in industrial and commercial electrical installations.

Advantages

The transformer offers a stable and linear conversion of primary current to a secondary output, enabling reliable measurement and protection functions. Its fixed design and defined conductor aperture simplify installation in tight panel spaces. The specified conductor diameter range ensures consistent magnetic coupling and measurement accuracy when installed according to recommended practice.

Suitable for

• Current measurement in distribution and control panels
• Protection circuits and motor control systems
• Retrofitting or adding metering points in switchgear
• Inductive sensing applications with single conductors 2.5–4 mm in diameter

When it may not be suitable

This fixed transformer is not appropriate where conductors exceed the specified 2.5–4 mm diameter range or where a split-core design is required for live conductor retrofitting without disconnection. It is also not intended for use as a primary protective device by itself; correct system-level protective relays and fusing should be used.

Key specifications

• Function: Fixed current transformer for inductive measurement
• Nominal secondary current: 150 A
• Conductor diameter range: 2.5–4 mm
• Colour: Black
• Mounting/readiness: Designed for installation in electrical panels and switchgear

How to use

Install the transformer so the single conductor passes centrally through the aperture that matches the 2.5–4 mm diameter range. Ensure the secondary output is correctly connected to the measuring instrument or protection device according to its wiring diagram and the installer follows local electrical codes. Verify polarity and tight electrical connections, and perform calibration or zero checks as required by the measuring equipment manufacturer.

What to consider before purchase

• Confirm the conductor diameter is within the 2.5–4 mm range
• Ensure the secondary nominal current (150 A) matches the downstream measurement or protection device requirements
• Determine whether a fixed-core or split-core transformer is needed for your installation method
• Check panel space and mounting accessibility for installation

Usage recommendations

Install and commission the transformer according to applicable safety standards and the instructions of the measuring/protection device. Use proper protective equipment during installation and verify system grounding and fuse coordination for safe operation.