Alternator A.R.K7F

A.R.K7F Alternator – PMG Excited, Brushless, and Heavy-Duty Industrial Alternator

The A.R.K7F alternator, designed and manufactured by Arken Power Solutions, is a heavy-duty three-phase, brushless synchronous alternator equipped with PMG excitation and MX321 AVR for precise voltage regulation and superior transient response. Delivering ±1% voltage accuracy, THD below 5%, and up to 96.4% efficiency, this model ensures high-quality, clean, and stable power generation for industrial, rental, telecom, and standby systems. Featuring Class H insulation, IP23 protection, and sealed-for-life bearings, the A.R.K7F guarantees durability, long service life, and consistent performance in harsh environments. Fully compliant with IEC60034, BS5000, NEMA MG1-22, CSA C22.2-100, and ISO9001, it provides an optimal balance between efficiency, stability, and reliability.

Alternator Model

A.R.K7F

50Hz (kVA)

1500

60Hz (kVA)

1775
Control System SELF EXCITED
A.V.R. MX341 WITH PMG
Voltage Regulation ± 1.0 %
Sustained Short Circuit >300% OF RATED CURRENT
Rated Power Factor 0.8

Electrical Performance

  • Type: Three-phase, brushless synchronous alternator with PMG excitation

  • Frequency: 50 / 60 Hz

  • Power Factor: 0.8

  • Voltage Range: 380/220V – 480/277V (configurable in star, delta, or parallel star)

  • Voltage Regulation: ±1.0%

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

  • Sustained Short Circuit Current: >300% rated current for 10 seconds

  • Efficiency: Up to 96.4% depending on frequency and load

  • Overload Capacity: 110% for one hour in a six-hour cycle

  • Telephone Harmonic Factor (THF): <2%

  • Telephone Interference Factor (TIF): <50

  • Short Circuit Ratio (1/Xd): 0.19 typical

  • Power Ratings (Winding 311):

    • 50 Hz: 1100–1375 kVA (Efficiency 96.0–96.4%)

    • 60 Hz: 1250–1650 kVA (Efficiency 95.7–96.2%)

  • Reactances (Per Unit at Rated kVA):

    • Xd (Synchronous): 2.26–3.23

    • X’d (Transient): 0.18–0.25

    • X’’d (Subtransient): 0.07–0.13

    • Xq (Quadrature): 2.04–3.16

    • X’’q (Quadrature Subtransient): 0.22–0.27

    • X₂ (Negative Sequence): 0.14–0.16

    • X₀ (Zero Sequence): 0.04–0.06

    • Leakage Reactance (XL): 0.03

  • Time Constants:

    • Transient (T’d): 0.3 s

    • Subtransient (T’’d): 0.03 s

    • Armature (Ta): 0.06 s

    • Open Circuit Field (T’do): 3.16 s

Construction & Design

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

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

  • Cooling: Self-ventilated air cooling

    • 50 Hz: 2.64 m³/s (5600 cfm)

    • 60 Hz: 3.17 m³/s (6720 cfm)

  • Frame: Rigid steel structure with cast aluminum front and rear covers

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

  • Rotor: Damped rotor dynamically balanced to BS6861 standards

  • Bearings:

    • Drive End: 6319 (sealed-for-life ball bearing)

    • Non-Drive End: 6228 (sealed-for-life ball bearing)

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

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

  • Inertia (WR²): 36.49–37.49 kg·m²

  • Winding Resistance:

    • Stator: 0.00126 Ω/phase (22°C, star connection)

    • Rotor: 1.41 Ω (22°C)

Dimensions & Weight

  • Rotor Weight: 1181–1244 kg

  • Stator Weight: 1541 kg

  • Complete Alternator Weight: 2982–3130 kg

  • Shipping Weight (Crated): 3054–3070 kg

  • Packing Dimensions: 194 × 105 × 154 cm

Regulation & Control

  • Excitation System: PMG excitation with brushless AVR

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

  • Voltage Regulation Accuracy: ±1.0%

  • Parallel Operation: Supported (AVR-dependent)

  • Protection Features:

    • Stator winding and bearing overheat protection

    • Anti-condensation heater (optional)

    • Low-speed voltage drop protection

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

  • Standards Compliance: IEC60034, GB755, BS5000, 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: 2.64–3.17 m³/s depending on frequency

  • Noise & Vibration: Dynamically balanced per BS6861 mechanical standards

Performance Summary

  • Efficiency Range: 95.7–96.4%

  • 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, railway, lighting tower, and refrigeration generator systems

Datasheet

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