Alternateur A.R.K274DS

Electrical Performance

• Type: Three-phase, brushless, self-excited synchronous alternator

• Frequency: 50 / 60 Hz

• Power Factor: 0.8

• Rated Voltage Range: 190–480 V (configurable in star, delta, or parallel star)

• Voltage Regulation: ±1.0%

• Total Harmonic Distortion (THD): <5% (balanced load), <1.5% (no-load)

• Sustained Short Circuit Current: >300% of rated current

• Efficiency: Up to 91.6% depending on voltage and frequency

• Telephone Harmonic Factor (THF): <2%

• Telephone Interference Factor (TIF): <50

• Excitation System: Self-excited, AVR-controlled

• AVR Models: SX460 (standard), SX440 optional, MX341 / MX321 (PMG optional)

• Short Circuit Ratio (1/Xd): 6.0 typical

Reactances (Per Unit, Saturated)

• Xd (Synchronous): 2.06–2.52

• X’d (Transient): 0.16–0.21

• X’’d (Subtransient): 0.10–0.15

• Xq (Quadrature): 1.17–1.49

• X’’q (Quadrature Subtransient): 0.14–0.21

• X₂ (Negative Sequence): 0.12–0.17

• X₀ (Zero Sequence): 0.07–0.10

• Leakage Reactance (XL): 0.06–0.07

• Time Constants:

  • Transient (T’d): 0.031 s

  • Subtransient (T’’d): 0.01 s

  • Open Circuit Field (T’do): 0.85 s

  • Armature (Ta): 0.0073 s

Construction & Design

• Insulation Class: H (125°C rise at 40°C ambient)

• Protection: IP23 (optional IP44 with 5–10% derating)

• Cooling: Self-ventilated air cooling

  • 50 Hz: 0.514 m³/s (1090 cfm)

  • 60 Hz: 0.617 m³/s (1308 cfm)

• Frame: Heavy-duty steel frame with cast aluminum front and rear covers

• Stator: Double-layer winding with auxiliary winding, 2/3 pitch eliminates triple harmonics

• Rotor: Damped cage rotor, dynamically balanced to BS6861 standards

• Bearings:

  • Drive End: 6315-2RS (ISO, sealed-for-life)

  • Non-Drive End: 6310-2RS (ISO, sealed-for-life)

• Overspeed Capability: 120% of rated speed (2250 rpm)

• Leads: 12 reconnectable leads (series star, parallel star, or delta connection)

• Stator Resistance: 0.038 Ω/phase (22°C, series star connection)

• Rotor Resistance: 1.26 Ω (22°C)

• Rotor Inertia (WR²): 1.1962 kg·m² (single bearing) / 1.1455 kg·m² (double bearing)

Dimensions & Weight

• Wound Rotor Weight: 149.37 kg (single bearing) / 138.41 kg (double bearing)

• Wound Stator Weight: 141 kg

• Complete Alternator Weight: 431 kg (single bearing) / 450 kg (double bearing)

• Shipping Weight: 458–476 kg (crated)

• Packing Dimensions: 105 × 67 × 103 cm

Regulation & Control

• Excitation: Self-excited, AVR-controlled

• AVR Models: SX460 (standard), SX440 / AS440 / MX341 / MX321 optional

• Voltage Regulation Accuracy: ±1.0%

• Parallel Operation: Supported (AVR-dependent)

• RFI Suppression: BS EN 61000-6-2 & BS EN 61000-6-4, VDE 0875G/N compliant

• Standards Compliance: IEC60034, GB755, BS5000, VDE0530, NEMA MG1-22, CSA C22.2-100, AS1359

• Certification: ISO9001 Quality Management System

Environmental Parameters

• Operating Temperature: –15°C to +40°C

• Relative Humidity: Up to 95% (non-condensing)

• Altitude: Up to 1000 m without derating

• Cooling Air Requirement: 0.514–0.617 m³/s depending on frequency

• Noise & Vibration: Balanced per BS6861 mechanical standards

Performance Summary

• Efficiency Range: 90.8–91.6%

• Voltage Dip (Transient Load): ≤25% at 0.8 PF

• Recovery Time: <0.5 seconds

• Locked Rotor Motor Starting: >300% rated current

• Applications: Prime power, standby, rental, telecom, mobile, lighting tower, refrigeration, and railway generator systems