The Siemens 3NJ6920-3BE12 is a pluggable bushing current transformer designed as a direct-fit accessory for 3NJ6 in-line switch disconnectors with fuses. With Class 0.5 accuracy and a 1 A secondary output, it is purpose-built for precision current measurement on 150 A circuits over extended signal cable distances.

Application

The 150/1 A ratio with Class 0.5 accuracy makes this CT suitable for applications requiring above-standard measurement precision — such as energy audits, power quality trending, and precision load profiling — without the regulatory overhead of legal-for-trade calibration. The 1 A secondary reduces resistive losses in signal wiring between the CT and remote monitoring or logging equipment. Typical deployments include centralized building energy management, industrial process monitoring, and data-center power distribution.

Installation

The pluggable design enables tool-free installation directly onto compatible 3NJ6 in-line switch disconnectors. The 21 mm bushing opening accommodates larger conductor cross-sections. The CT snaps into the dedicated accessory port on the switch disconnector body — no additional wiring or mounting hardware is needed.

Decision Parameters