0.75 kW drive for HVAC fan and pump loads
The ATV21W075N4C is a 0.75 kW Altivar 21 variable frequency drive designed for asynchronous motors in constant-torque and variable-torque applications — typically HVAC fans, pumps, and compressors where the load profile matches the PI regulator and the 1:10 speed range. It accepts 380–480 V three-phase input at -15%/+10% tolerance, drawing 1.4 A at 480 V or 1.7 A at 380 V, with an apparent power of 1.6 kVA at 380 V.
Switching frequency and derating
The adjustable switching frequency spans 6–16 kHz, but above 12 kHz a derating factor applies — expect reduced continuous output current if you push the carrier frequency to quiet motor whine. Transient overtorque is rated at 120% of nominal motor torque for 60 seconds, which gives headroom for starting high-inertia loads like centrifugal fans.
EMC and standards compliance
An integrated Class B EMC filter is fitted as standard, and the drive carries CE marking with multiple IEC/EN 61800-3 environment categories (C1, C2, C3) plus EN 55011 Group 1 Class B — meaning it is suitable for residential and light-industrial installations without an external filter in most cases. Pollution degree 2 per IEC 61800-5-1, and the dielectric strength is tested at 3535 V DC between earth and power terminals, 5092 V DC between control and power terminals.
Communication and option cards
The drive includes a 2-wire RS-485 physical interface with RTU protocol, configurable baud rates of 9600 or 19200 bps, and supports up to 247 addresses on the bus. Optional communication cards are available for APOGEE FLN, BACnet, LonWorks, and METASYS N2 — important for building management system integration.
Sourcing and lifecycle
No official successor or cross-reference is recorded for this order code; the Altivar 21 series remains the current platform for this power class.