The Delta VFD38AMH43ANSAA is a Frame F frequency converter sized for a 18.5 kW (25 HP) motor on a 380–480 V three-phase supply. The 41.5 A rated output current is the continuous figure the drive can deliver to the motor; the heavy-duty rating of 41.8 A and normal-duty rating of 45.7 A tell you the overload headroom — heavy duty for constant-torque loads like conveyors or extruders, normal duty for variable-torque fans and pumps. Natural cooling means no fan to fail or clog, but it also means the drive sheds heat through the heatsink alone, so panel airflow matters — don't box it in tight with heat-sensitive kit.
Frame size and panel fit
Frame F is the physical footprint — it tells you the mounting hole pattern, gland-plate space, and bus-bar layout without pulling the manual. If you're swapping an older drive into an existing panel, check that the Frame F cutout and fixing centres match the legacy footprint — Delta's Frame F is a known size across this series, so a retrofit often lands without re-drilling the backplate.
Carrier frequency and cooling
Carrier frequency is adjustable from 2 to 15 kHz, factory-set at 4 kHz. A higher carrier quiets the motor but increases switching losses in the IGBTs — with natural cooling, pushing above 8 kHz may require derating the output current. The 47–63 Hz frequency tolerance means it handles genset or weak-grid supply without tripping.