Delta VFD-M Series AC Drive

Description

• VFD004M21A​ decoding: VFD​ = Variable Frequency Drive; 004​ = 0.4 kW​ rated (HD const torque) — that’s 0.5 Hp; M​ = VFD-M series (micro, V/f only, ultra-compact); 2​ = voltage class; 1​ = single/three-phase input nuance; A​ = standard. Delta VFD-M voltage suffix detail: “21”​ = 200–240V 1φ/3φ input​ (single-phase 200–240V is the typical use — VFD-M 0.4kW draws ~5A @230V 1φ input, output 0.4kW @3φ to motor); there’s also “23”​ = 380–480V 3φ for larger M frames (VFD007M23A etc.). → VFD004M21A = 0.4kW / 0.5Hp, 200–240V 1φ/3φ input, VFD-M micro, standard.​ ND (pump/fan) rating = ~0.75 kW / 1 Hp (since VFD-M is V/f only, ND/HD split is modest).
• VFD-M family range: 0.2 kW – 2.2 kW (0.25–3 Hp) across VFD002M… to VFD022M…, voltages 230V / 460V. All share: ultra-compact (book-style thin), V/f control only​ (no sensorless vector — unlike VFD-E which has “Vector Control”), overload 120% for 1 min​ (vs VFD-E’s 150%/60s — M is gentler), no DC reactor​ (vs VFD-E has it), no Easy PLC​ (vs VFD-E has 140-step), built-in RS-485 Modbus RTU​ (same as VFD-E — Delta’s standard RJ45-style terminal), built-in PID​ (basic, sleep/wake), brake chopper built-in​ (small frames too — +B/-B terminals).
• VFD-M vs VFD-E quick compare​ (since we covered VFD-E last):
  Feature	VFD-M (this one)	VFD-E (previous)
  Position	Entry micro	Compact smart
  Control	V/f only	V/f + Sensorless Vector
  Overload	120% / 1 min	150% / 60s
  DC Reactor	❌	✅ Standard
  Easy PLC	❌	✅ 140 steps
  DIN Rail	Some frames (up to 0.75kW?) — M is mostly panel-bolt; E is DIN up to 15kW	✅ DIN up to 15kW
  Price	Lowest	Mid
  Best For	Tiny OEM, fan/blower speed ctrl, simple pump	Small machine w/ sequencing need

Key Features

• Power (VFD004M21A): 0.4 kW / 0.5 Hp HD; ~0.75 kW / 1 Hp ND (pump/fan)
• Input Voltage: 200–240V AC, 1φ or 3φ​ (typical use = single-phase 230V in, 3φ out to motor — VFD-M is popular as single-phase-in drive for small motors)
• Output: 0–240V 3φ, V/f control (linear / V/f with torque boost)
• Overload: 120% rated for 1 min (gentler than VFD-E’s 150%/60s — M is for steady loads, not shock loads)
• Built-in Brake Chopper: Yes (+B/-B terminals — even this tiny 0.4kW has it)
• Built-in PID: 1-loop, basic (sleep/wake)
• Communication: RS-485 Modbus RTU built-in (same Delta RJ45-style terminal as VFD-E)
• Control Terminals: 4× DI (24V DC sink/source), 1× AI (0–10V / 4–20mA), 1× AO (0–10V / 4–20mA), 1× Relay (Form A)
• Country of Origin: Taiwan / China (Delta Electronics)

Technical Specifications (VFD004M21A — 0.4 kW, 200–240V, VFD-M)

Warranty & After-Sales

• Factory new units: 12 months warranty
• Refurbished units: 3-6 months warranty (power-up + motor no-load spin → verify V/f ramp, Modbus poll)
• Technical support for:
  • VFD-M vs VFD-E vs VFD-EL choice (M = tiniest 0.2–2.2kW, V/f only, cheapest; EL = 0.2–3.7kW economy but wider range; E = smart compact with Vector+Easy PLC — pick per feature need)
  • VFD-M voltage suffix: 21​ = 200–240V 1φ/3φ (VFD004M21A / VFD007M21A etc.); 23​ = 380–480V 3φ (VFD004M23A doesn’t exist — M at 380V starts at VFD007M23A 0.75kW? Actually M 380V: VFD007M23A 0.75kW, VFD015M23A 1.5kW, VFD022M23A 2.2kW — 0.4kW M only in 21 suffix)
  • Single-phase input note: VFD004M21A accepts 1φ 230V input​ (5A draw) → outputs 3φ to motor (2.5A) — popular for retrofitting single-phase shop air compressors / small pumps to VFD control without 3φ supply
  • VFDSoft first connect (RS-485 USB dongle → VFDSoft → scan → upload/download)
  • RS-485 Modbus wiring (same Delta pinout as VFD-E: RJ45-style, pins 1/2=SG+/-, 3=+24V, 4=GND)
  • No sensorless vector warning: VFD-M is V/f only​ — if you need low-speed torque (hoist, winch, mixer startup), VFD-M will struggle — upgrade to VFD-E (has sensorless vector) or VFD-C2000 (flux vector)
• Optional: Remote keypad VFD-PU01, brake resistor, EMI filter, VFDSoft (free from Delta)

Delivery Time

• Standard delivery: 3-5 working days (stock NOS)
• Express shipping available upon request

Why Choose Our Store

• Genuine Delta VFD-M drives — not gray-market (V/f algo & brake chopper calibration critical at 0.4kW micro size)
• Global supply network with competitive pricing on Delta VFD-M/EL/E/C2000 family
• Expertise in Delta entry-level VFD system (M vs E vs EL选型, 21 vs 23 voltage suffix, single-phase input 230V→3φ out wiring, VFDSoft commission)
• Comprehensive technical documentation (VFD-M terminal layout, MODBUS pinout, V/f torque boost setting, single-phase input wiring diagram)
• Responsive customer service and support

Applications

• Single-Phase Shop Retrofit (air compressor, small pump, fan): VFD004M21A takes 1φ 230V in​ (standard residential/workshop supply) → outputs 3φ to motor​ — lets you VFD-control a 3φ 0.4kW motor even where only single-phase power exists. Popular for small workshop air compressor (3φ motor on 1φ supply via VFD), exhaust fan speed control.
• OEM Small Machines (labeling, small conveyor, feeder): 0.4kW / 0.5Hp covers tiny drives — VFD-M book-thin footprint saves panel space. V/f only is fine for constant-speed-ish applications (fan, centrifugal pump, conveyor steady speed).
• HVAC Small Fan / Blower: ND 0.75kW rating, built-in PID sleep/wake → small inline fan or make-up air damper motor control.
• Cost-Down Projects: Compared to VFD-E (7.5kW we covered) or PowerFlex 4M/525 — VFD-M at 0.4kW is cheapest Delta option. Trade-off: V/f only (no low-speed torque), 120%/1min overload (no shock load), no Easy PLC, no DC reactor. For steady centrifugal loads → perfect; for hoist/mixer startup → wrong choice, go VFD-E.