What voltage do the LFT20 and LFT54 run on?
Both kits run on 12V DC and are supplied from the tractor's 12V negative chassis electrical system. The LFT20 draws 10A on average; no numeric manufacturer value is given for the LFT54's current consumption, and the unit is current protected. On 24V systems no direct connection should be made; a DC-DC converter of suitable capacity must be used.
Base your supply design on these values:
- Nominal voltage: 12V DC. With the tractor running, the line voltage is typically between 13.8-14.4 V because of the alternator; this is normal.
- Current: The LFT20 draws 10A on average. As a general rule, fuse selection takes about 125% of the load; that gives a calculated 12.5A, which in practice means a 15A fuse. This is an engineering derivation, not a manufacturer statement.
- Wire: For a 10A load and roughly 3 m one-way distance, a cross section of at least 2.5 mm² (about 14 AWG) is recommended; at 12V, the 3% voltage drop limit leaves only 0.36 V of margin.
- Polarity: On a negative chassis system the negative supply is connected to a clean bare metal chassis point.
Repeated use with the engine off tires the battery; for prolonged use, run the engine. The kit draws meaningful current only while moving.
Full topic: Converting a tractor hydraulic lever to electronic control