The generator set shall capable of delivering and maintaining a continuous power of not less than the kVA specified at 0.8 lagging power factor, 415 volts, three phase, 4 wire, 50 Hz supply under the operating conditions specified. The generator set shall be designed for cold starting and be capable of supplying the rated kVA specified in not more than 15 seconds from initiation of the starting procedure. The generator set shall comply with relevant parts of ISO 8528. Unless specified otherwise the generator set shall be of performance class G2 of ISO 8528-5 having the frequency and voltage characteristics as following:
(a) Frequency droop: < 5 %
(b) Steady-state frequency band: < 1.5 %
(c) Transient frequency deviation –
(i) 100% sudden power decrease: < + 12 %
(ii) sudden power increase: < – 10 %
(d) Frequency recovery time: < 5 s
(e) Steady-state voltage deviation –
(i) for single operation: < ± 2.5 %
(ii) for parallel operation: < ± 1 %
(f) Voltage unbalance –
(i) for single operation: < 1%
(ii) for parallel operation: < 0.5 %
(g) Range of voltage setting: ± 5 %
(h) Transient voltage deviation –
(i) 100% sudden power decrease: < + 25 %
(ii) sudden power increase: < – 20 %
(i) Voltage recovery time: < 6 s
Unless specified elsewhere, the generator set shall perform within the operating limits for the performance class specified when the generator set is subjected to sudden power increase from 0% to 50%, 50% to 80% and 80% to 100% of the rated kVA at 0.8 lagging power factor specified. In the case where the load profiles are specified, the generator set shall perform within the operating limits with respect to the loading requirements.

The generator set shall be configured and mounted on a base frame and the mounting shall be of fully resilient type. The base frame shall be of prefabricated structural steel channel type of all welded construction. The base frame shall be provided with lifting points for transportation. Spring type vibration damper shall be installed and supplied together with generator set by the registered generator set supplier.

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