The Delta VFD25AMH43ANSAA is a Frame E frequency converter from the VFD-MH series, rated for 11 kW (15 HP) motor applications on a 3-phase 380-480 VAC supply. It delivers 28.0 A continuous output current, with a Heavy Duty input rating of 27.5 A and a Normal Duty input of 30.8 A — the Heavy Duty figure is the one to size branch protection by if the load profile includes constant-torque segments like conveyors or positive-displacement pumps.
The Heavy Duty / Normal Duty split governs the thermal capacity. Heavy Duty 27.5 A input (27.5 A input current under heavy duty) supports constant-torque loads — conveyors, extruders, positive-displacement pumps — where the motor pulls rated current across the speed range. Normal Duty 30.8 A (30.8 A input under normal duty) applies to variable-torque loads like centrifugal pumps and fans, where current drops with speed. The 28.0 A rated output current is the continuous limit at the motor terminals; stay under it to avoid I²t trips on sustained runs.
Input and output considerations
The operating voltage range spans 323-528 VAC, covering nominal 380 V, 400 V, and 480 V grids with the stated -15% / +10% tolerance. Frequency tolerance is 47-63 Hz, so it handles weak generator supplies or off-nominal mains without tripping. The carrier frequency is adjustable from 2 to 15 kHz (factory set at 4 kHz); raising it quiets the motor but increases heat dissipation in the drive — expect derating above 4 kHz if ambient exceeds 40 °C. The EMC filter is listed as optional, meaning the drive ships without an internal filter as standard; if the installation must meet EN 55011 Class A or B conducted emissions, an external filter (or the filtered variant of this model) is required.