The Siemens 3NJ6930-3BF12 is a pluggable bushing current transformer for the SENTRON 3NJ6 series of in-line switch disconnectors with fuses. It provides a 200/1 A transformation ratio with Class 0.5 accuracy and a 3.75 VA burden — the highest burden rating in the plug-in 3NJ6930 range — making it the preferred choice for precision measurement applications that demand multiple instruments or extended secondary wiring.

Class 0.5 Accuracy at 200 A

Where the 3BF11 provides Class 1 accuracy for general monitoring, the 3BF12 delivers Class 0.5 precision at the same 200 A primary current. This makes it suitable for applications that require high accuracy but do not need legal-for-trade calibration — such as internal energy cost allocation, sub-metering, or precision process monitoring.

3.75 VA Burden for Demanding Secondary Loops

The 3.75 VA burden rating supports more instruments in series, longer cable runs, or both — without the transformer approaching saturation. This is the key differentiator from the 2.5 VA 3BF11: if the measurement loop requires driving an analog meter, a transducer, and a PLC input across 20 meters of control wiring, the 3BF12 has the headroom to maintain accuracy.

Decision Parameters