| Three-Phase Output | 400/230 V, 50 Hz, 3-phase, 4-wire | A common low-voltage configuration for commercial and industrial installations. | Confirm the required voltage, frequency, phase sequence, and neutral arrangement. |
| Power-Factor Basis | 0.8 lagging | At 0.8 power factor, a 500 kVA set corresponds to approximately 400 kW of active power. | Match the generator rating to motor loads, power-factor correction equipment, and harmonic-producing loads. |
| Prime-Power Duty | Variable-load operation; average load commonly limited to 70% of prime rating over a defined operating period | Prime power is intended for variable loads where operating hours and load profile are controlled according to ISO 8528 requirements. | Request the exact prime-power definition, allowable overload, annual running hours, and load profile assumptions. |
| Standby-Power Duty | Emergency backup service with limited annual operating hours | Standby ratings are designed for utility interruptions rather than continuous or base-load operation. | Do not use a standby rating for continuous operation without written engineering approval. |
| Rotating-Machine Standard | IEC 60034-1 | Covers key requirements for rotating electrical machines, including ratings, performance, temperature-rise limits, and testing principles. | Request the applicable edition, declaration of conformity, test records, and alternator technical datasheet. |
| Generating-Set Standard | ISO 8528 series | Provides the principal framework for reciprocating-engine AC generating sets, including ratings, performance, and test requirements. | Check whether the quoted performance test follows the relevant ISO 8528 parts. |
| Alternator Configuration | 4-pole synchronous alternator; 1,500 rpm at 50 Hz | A 4-pole machine operating at 1,500 rpm produces 50 Hz at synchronous speed before slip and control considerations. | Verify speed, frequency, excitation system, voltage regulation, and transient-performance data. |
| Insulation and Enclosure | Typical industrial reference: Class H insulation; IP23 alternator protection | Class H indicates the insulation-system temperature class; IP23 provides protection against solid objects above 12.5 mm and spraying water up to 60° from vertical. | Confirm the actual insulation class and IP rating for the selected configuration and installation environment. |
| Voltage Regulation | Automatic voltage regulation; final value depends on alternator and control system | The AVR maintains generator voltage as load changes, but performance depends on load type, excitation design, and controller settings. | Obtain steady-state regulation, transient voltage dip, recovery time, and motor-starting data. |
| Protection Functions | Overspeed, low oil pressure, high coolant temperature, over/under-voltage, and over/under-frequency | These functions help protect the engine, alternator, connected loads, and operators during abnormal conditions. | Review the controller alarm list, shutdown thresholds, event log, and emergency-stop arrangement. |
| Factory Acceptance Testing | Load-bank test at specified load points | Testing can validate voltage, frequency, temperature, fuel consumption, load response, and safety shutdowns before shipment. | Specify test load, duration, instruments, acceptance limits, and whether witnessed testing is available. |
| Service and Parts Support | Commissioning, preventive-maintenance schedule, troubleshooting, and replacement-parts availability | Lifecycle support directly affects availability, maintenance cost, and restoration time after a fault. | Confirm response time, technician coverage, warranty scope, service intervals, and parts lead times in writing. |