Victron GX Tank 140 connections

GX Tank 140 reads four 0–10 V or 4–20 mA transmitters through a Victron GX device. A resistive fuel sender cannot be connected directly. USB powers the interface; the external VIN terminals supply the sensors on channels 1 and 2, not the interface itself. Channels 3 and 4 have an isolated 24 V sensor supply, limited to 20 mA per channel. See power arrangements, PDF p. 5.

For a three-wire voltage transmitter, supply goes to Vout, signal to In, and return to GND. A two-wire current transmitter connects between Vout/24 V and In; the channel GND terminal is unused in that arrangement. Select the actual input type in the GX settings. The same-looking connector supports two different circuits, so copying a voltage-sender drawing for a current loop produces misleading readings. See voltage wiring, PDF p. 6 and current-loop wiring, PDF p. 7.

Check transmitter consumption before using the internal 24 V supplies. The 20 mA limit belongs to each sensor supply; it is not a published consumption figure for the complete GX system. Protect an external VIN feed for its cable and sensor circuit. Keep the USB connection accessible and route sender cables away from noisy power wiring. No universal VIN fuse is stated in the cited manual.

Configure tank function, capacity and transmitter endpoints in the GX device, then compare empty and full readings against known levels. A current-loop reading stuck around 40–55% can result from an overloaded sensor supply: the manual describes a tripped protection state that still passes some current. Power down, check wiring and load, and restore power after correction; do not compensate for this fault by changing calibration. See troubleshooting, PDF p. 14.