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Standards for purchasing diesel generator sets

April 11, 2022
1. Appearance requirements
(1) The limit size, installation size and connection size of the diesel generator set are in line with the factory product drawings approved by the prescribed procedures
(2) The welding of the unit should be firm, the welding seam should be uniform, and there should be no defects such as welding penetration, undercut, slag inclusion and porosity, and the welding slag and flux should be cleaned up; the paint film should be uniform, without obvious cracks and falling off; , No leakage plating spots, corrosion and other phenomena; the unit fasteners should not be loose.
(3) The electrical installation of the diesel generator should comply with the circuit diagram, and the connection of each wire of the unit should have obvious signs that are not easy to fall off.
(4) Diesel generators should have well-grounded terminals.
(5) The contents of the diesel generator signs are complete
2. Insulation resistance and dielectric strength
(1) Insulation resistance: The insulation resistance of each independent electrical circuit to ground and between circuits should be greater than 2M
(2) Dielectric strength: each independent electrical circuit of the unit should be able to withstand the AC test voltage for 1min to the ground and between the circuits, and there should be no breakdown or flickering phenomenon.
3. Phase sequence requirements. The phase sequence of the terminals of the diesel generator set control panel should be sequenced from left to right or from top to bottom when viewed from the front of the control panel.
4. Diesel generators are required to maintain a ready-to-run state. The unit shall have a heating device to ensure that the oil temperature and cooling medium temperature during emergency start and rapid loading are not lower than 15℃
5. Reliability check of automatic start power supply and automatic shutdown
(1) After receiving the start command of automatic control or remote control, the diesel generator should be able to start automatically.
(2) When the unit fails for the third time after the automatic start-up, a start-up failure signal shall be sent; when there is a standby unit, the program start-up system shall be able to automatically transmit the start command to another standby unit.
(3) The time from the issuance of the automatic start command to the supply of power to the load should not exceed 3 minutes
(4) After the diesel generator is successfully started automatically, the first load should not be less than 50% of the nominal load.
(5) After receiving the shutdown command of automatic control or remote control, the unit should be able to stop automatically; for the standby unit used in conjunction with the mains grid, when the grid returns to normal, the diesel generator should be able to automatically switch or stop automatically, and its shutdown method will stop The delay time should be in accordance with the product technical conditions.
6. Automatic startup success rate. The success rate of automatic startup is not less than 99%.
7. No-load voltage setting range requirements. The no-load voltage setting range of the unit is not less than 95%-105% of the rated voltage.
8. Requirements for automatic replenishment function. The unit should be able to automatically charge the starting battery.
9. Requirements for automatic protection function. The unit should have protections for phase loss, short circuit (not more than 250KW), overcurrent (not more than 250KW), overspeed, high temperature of water temperature cylinder, and low oil pressure.
10. Sine distortion rate of line voltage waveform. Under no-load calibration voltage and calibration frequency, the sinusoidal distortion rate of line voltage waveform is less than 5%.
11. Voltage steady state regulation rate
≤250KW >250KW
3% 2%
12. Voltage transient regulation rate
≤250KW >250KW
20% 15%
13. Voltage stabilization time
≤250KW >250KW
≤2s ≤1.5s
14. Voltage fluctuation rate
≤250kw >250kw
0.8% 0.5%
15. Frequency steady state adjustment rate
≤250kw >250kw
3% 3%
16. Frequency transient adjustment rate
≤250kw >250kw
9% 9%
17. Frequency stabilization time
≤250kw >250kw
5s ≤5s
18. Frequency Volatility
≤250kw >250kw
≤0.8% ≤0.5%
19. Voltage deviation under three-phase asymmetric load
Under the condition of 25% three-phase symmetrical load, the diesel generator set should be able to work normally, and the maximum or minimum line voltage should be 5% of the average value of the three-line voltage.
20. Noise
The average value of noise sound pressure at 1m from the diesel engine and generator of the unit:
≤250KW >250KW
≤102db(A) ≤108db(A)
21. Fuel consumption rate. The rated power of the unit is within the range of 120
22. Diesel generator consumption rate. The rated power of the unit is >40KW, and the consumption rate of the unit is ≤3.0G/Kw.H
23. Run the test under calibration conditions
Under the specified working conditions (section 4.2 in GB2820), the unit can run normally and continuously for 12 hours (including overload  10% operation for 1 hour) under the calibration conditions, and the diesel generator set should be free of water leakage and air leakage.
24. Remote control, remote signaling and telemetry performance