Yanmar YL4000M-5B

A three-cylinder diesel engine drives a generator delivering 5.1 kW, or 5.1 kVA, continuous output at 230 V and 50 Hz, supplying four floodlights of 1,000 W each, 4,000 W in total. The telescopic mast extends to a 9 m working height; in transport condition the unit measures 4,344 x 1,450 x 1,890 mm, and in working condition with the mast extended, 2,762 x 2,781 x 9,068 mm. The tank holds 114 litres, and total weight is 834 kg.

The large gap between transport and working height shows the operating principle: for travel on the road or between sites the mast is retracted, while on site it is extended to lift the floodlights above barriers, excavations and traffic areas. Light towers like this are used on road construction sites, earthworks, events and disaster response, wherever grid-independent, localised lighting is needed over long periods without a power connection.

When buying one used, check the mast guide, the extension mechanism and the cable or hydraulics that raise the mast, as well as bearing play in the extended state. The generator should be checked for insulation values and the floodlights for intact fittings and cable glands, since moisture in outdoor lighting is a frequent cause of failure; it is also worth checking running hours and the diesel engine's service condition.