Will the LFT20 or LFT54 work on vehicles with a 24V electrical system?
No. The LFT20 and LFT54 are designed for a 12V DC supply, and connecting them directly to a 24V line will permanently damage the motor and the embedded control board in the LFT54. To use them on a 24V vehicle you need a 24V/12V DC-DC converter with sufficient current capacity; since the LFT20 draws 10A on average, the converter must be able to supply that load continuously.
The large majority of modern farm tractors are 12V negative chassis, so the issue usually comes up in applications based on construction machinery or heavy commercial vehicles.
If use on a 24V line is unavoidable:
- Converter selection: For the LFT20, use an isolated DC-DC converter that can deliver a continuous output above the 10A average current, preferably 15A or more. The surge current at start-up is above the average; the converter must handle it without going into overcurrent protection.
- Fuse: Fit a fuse on both the input and the output side of the converter; for the LFT20's 10A average current, 15A is recommended in practice; this is an engineering derivation, not a manufacturer statement.
- Voltage check: Measure the converter output while the kit is running; if the voltage drops noticeably under load, the capacity is insufficient.
Taking the supply from only the 12V half of the battery bank is strongly discouraged; the batteries charge unevenly and their life is shortened. An installation of this kind rests on the user's responsibility, not on a manufacturer statement.
Full topic: Converting a tractor hydraulic lever to electronic control