Delta VFD004EL21A 0.4kW 0.5HP Single Phase to Three Phase VFD

Overview

The Delta VFD004EL21A is a 0.4 kW (0.5 HP) panel-friendly variable frequency drive (VFD) from Delta’s VFD-EL Series family. It runs a standard three-phase motor from an ordinary single-phase 230 V mains, rated at 2.5 A, to drive motors up to 0.4 kW / 0.5 HP. This single-to-three-phase capability makes it especially useful in Indian workshops, OEM panels and small machinery where only a single-phase supply is available but a standard three-phase induction motor still needs smooth, controllable speed. With V/f (scalar) control with a 3-point adjustable V/f curve and an output range of 0.1–600 Hz, the VFD004EL21A gives precise, stepless speed control for variable-torque and constant-torque loads alike. Supplied with a built-in keypad, it is quick to commission for basic speed control and equally at home inside an OEM control panel.

Key Features

• Input: 1-Phase 200–240 V AC, 50/60 Hz
• Output: 3-Phase 0–240 V AC, 0.4 kW / 0.5 HP, rated 2.5 A
• Output frequency 0.1–600 Hz
• Overload capacity 150% of rated current for 60 seconds
• Built-in PID feedback control
• RFI switch and DC-bus sharing for side-by-side installation
• High-precision current detection with full electronic protection
• Communication: RS-485 (RJ-45), Modbus RTU
• Enclosure: IP20

Technical Benefits

The 2.5 A rating with 150% of rated current for 60 seconds gives the breakaway headroom that belt, pump and small-machine loads need at start-up without nuisance tripping. Running fans and pumps at variable speed instead of a fixed 50 Hz cuts energy use sharply—on these loads, power scales with roughly the cube of speed—while soft start and stop reduce mechanical and belt wear and eliminate direct-on-line inrush current. The built-in EMI filter helps the panel meet electromagnetic-compatibility expectations without a separate filter, and DC-bus sharing lets several drives sit side by side to save cabinet space.

Selection & Compatibility

The VFD004EL21A pairs with standard three-phase 230 V induction motors up to 0.4 kW / 0.5 HP. As a sizing rule, match the drive to the motor’s full-load current rather than its kW alone: confirm the motor draws no more than 2.5 A, and for heavy constant-torque or high-inertia loads consider the next frame up for extra overload margin. Make sure a single-phase 230 V supply is available at the machine. For long motor cables or EMC-sensitive installations, add the recommended output reactor or a zero-phase core. Our engineers can confirm drive sizing, braking-resistor requirements and key parameter settings before you place the order.

Applications

Thanks to its single-phase input, it is a popular choice where three-phase mains is not available:

• laboratory and test rigs
• small exhaust and ventilation fans
• benchtop and DIY machinery
• dosing and metering pumps
• small monoblock and circulation pumps
• conveyor turntables and feeders
• small mixers and stirrers

About the Delta EL Series

The Delta VFD-EL is a proven new-generation micro-type AC drive built for simple, cost-effective speed control. It combines a genuinely compact footprint with a built-in EMI filter, RFI switch, built-in keypad, built-in PID control and Modbus connectivity, and supports optional Profibus, DeviceNet, CANopen and LonWorks modules. DC-bus sharing allows side-by-side mounting to save panel space.