YKA072DEC 72 Inch Direct Drive Circulation Fan 345rpm 70dB Three Phase 380V

The Numbers Behind a Barn Fan

Specification sheets for large fans tend to list one impressive figure and leave the rest vague. This page takes the opposite approach: it sets out the electrical and mechanical values that decide whether a fan suits a building, then explains what each one means in operation.

Electrical values

• Input power 2 kW: the figure used to size cable and protection, not a marketing rating.
• Three phase 380 V 50 Hz supply: standard agricultural wiring, no inverter required for fixed-speed running.
• 345 rpm: slow enough that blade noise sits below speech level, fast enough to reach the far wall.
• 70 dB or lower measured at the fan: a conversation can be held beside it.

Mechanical values

Reading the specification correctly

A direct drive fan couples the blade hub straight to the motor shaft, so there is no belt to tension, slip or replace, and no bearing pillow blocks to align on site. That removes the two most common causes of downtime on belt-driven agricultural fans. The trade-off is that the motor must be built for slow, high-torque duty, which is why a permanent magnet brushless design is used rather than a standard induction motor with a speed reducer.

Because the fan is often run through a variable frequency drive, the winding is specified for inverter duty with class F insulation, and the speed range from 20 to 100 per cent stays inside the motor's thermal envelope without forced cooling.

Planning a installation

Allow one fan per 15 to 20 m of building length in a typical loose housing shed, mounted at 3 to 3.5 m and angled slightly downward along the ridge. Keep 1.5 m clear behind the intake, and protect the supply with a circuit breaker rated for the motor's starting current.

Share your building drawing and we will return a fan layout with cable sizes and mounting heights marked.