The 3NJ6900-4HG22 is a pluggable bimetal analogue panel ammeter for the SENTRON 3NJ6 series of in-line switch disconnectors with fuses. It provides local current indication directly at the switchboard without external wiring or auxiliary power.

Bimetal Thermal Measurement

Unlike moving-iron instruments that track instantaneous current, the bimetal movement responds to the heating effect of the current. This provides inherent thermal damping against short-duration surges — the preferred choice for motor feeders, transformer primaries, and any circuit where inrush currents must not trigger false readings. The 250/5 A scale matches the globally common 5 A CT secondary standard.

Key Parameters

Pluggable Design

All 3NJ6900 ammeters share a common plug-in interface that mates directly with the 3NJ6 disconnector front accessory bay. No tools, no wiring, no separate power supply — just plug in and read. The same bay accepts moving-iron ammeters, bimetal ammeters, or blank covers, letting panel builders standardize on one disconnector platform and configure metering per feeder.