TAIYO LX Series Generator Common Troubleshooting and Maintenance Guide

Confirm whether the generator speed is stable (within ± 0.5% of rated frequency).

3.2 Transient voltage exceeding the standard (sudden loading and unloading of load)

Standard requirement: When suddenly adding 100% load (power factor ≤ 0.4), the maximum voltage drop should be ≤ 25%, and it should return to within -3% of the steady-state value within 2 seconds.

Voltage drop exceeding 25%:

Slow response of excitation system: The "gain" or "response" setting of AVR can be adjusted to be higher.

Low load power factor: Try to increase the natural power factor of the load as much as possible.

If the excitation winding of the exciter is broken or the rotating rectifier (diode) is damaged: stop the machine and check the rotating rectifier module (varistor and diode), and measure its forward/reverse resistance.

Recovery time too long (>2s): The AVR integration time constant is too large. You can lower the "integration gain" or set it to a faster recovery mode.

3.3 Insufficient voltage regulation range

The LX series typically allows for voltage adjustment of ± 5% at no-load rated speed. If the rated value cannot be adjusted:

Check if the "upper/lower limit" potentiometer of AVR has been mistakenly activated.

Measure the DC resistance of the stator winding of the exciter to determine if there is a turn to turn short circuit.

For LX-H, check if the output voltage of PMG is too low (possibly due to demagnetization of the magnetic steel).

Waveform distortion and harmonic problems

The distortion rate (deviation factor) of the no-load voltage waveform is specified to be ≤ 10%. If it exceeds the standard, it may cause downstream sensitive equipment to malfunction or overheat.

Reason: Short circuit between turns of stator winding, saturation of iron core, malfunction of rotating rectifier or grounding of rotor winding.

Detection: Use a harmonic analyzer to measure the harmonic content (total harmonic distortion THD) of the line voltage. Focus on the 3rd, 5th, and 7th harmonics.

handle:

If there is slight distortion (<15%) and the load is a regular motor, it can continue to operate.

If the distortion is severe, it is necessary to check whether the stator winding is damp or the inter turn insulation is damaged; High voltage megohmmeter can be used to test insulation.

For LX-G, you can try replacing the AVR to improve waveform feedback.

Mechanical and bearing failures

5.1 Overheating or abnormal noise of bearings

The LX series uses ball or roller bearings, and most models come with a re lubrication device (grease nozzle).

Abnormal noise: Bearing oil shortage, fatigue peeling, or damaged cage. Stop the machine and manually rotate the rotor to feel if there is any jamming or clicking sound.

Overheating: Excessive grease or model mismatch. High temperature lubricating grease of the specified grade (such as Shell Alvania 2, suitable for temperatures ranging from -25 ° C to+120 ° C) should be used, with a filling amount of 1/3 to 1/2 of the bearing chamber.

Maintenance cycle: Add lubricating grease every 2000 hours of operation or every six months; Replace bearings every 3-5 years or when abnormalities occur.

5.2 Excessive vibration

Reason: Poor coupling alignment, rotor dynamic balance failure, fan damage, or loose anchor bolts.

Diagnosis: Measure the horizontal/vertical vibration of the bearing position using a vibration meter (ISO 10816-3 standard). If the vibration exceeds 7.1mm/s (50Hz) or 7.5mm/s (60Hz), the machine needs to be shut down for maintenance.

Solution: Re check the alignment of the SAE adapter and coupling (allowable radial deviation ≤ 0.05mm, angle ≤ 0.1mm/m).

Insulation and environmental maintenance

6.1 Insulation level and temperature rise

The LX series standard insulation level is F level (allowing a temperature rise of 105K and a maximum operating temperature of 155 ° C). If there is long-term overload or poor ventilation, the insulation will accelerate aging.

Inspection: Use an infrared thermal imaging device to monitor the hotspots of the winding; Measure insulation resistance (with a 500V megohmmeter, not less than 5M Ω in cold state and not less than 1M Ω in hot state).

Prevention: Clean the ventilation openings (inlet/outlet hoods) of the casing every six months. LX-G and LX-E are self ventilated (IP20), ensuring free circulation of surrounding air.

6.2 High humidity, salt spray, and low temperature environments

Optional protective measures include:

Anti condensation heater: put into operation during long-term shutdown to prevent the winding from absorbing moisture.

Special treatment for coil wrapping (anti high humidity/salt spray): Used for seaside or chemical plants.

Low temperature measures (-5 ° C to -20 ° C): Replace the low-temperature grease, install a heater, and adjust the low-speed protection threshold of the AVR.

If there is no optional installation on site and the environment is harsh, the insulation resistance should be measured frequently. If it drops, hot air or low current heating should be used for dehumidification.

Overload and short circuit protection

7.1 Continuous overload capacity

The generator can withstand 1.5 times the rated current (cos φ not less than 0.8) for 30 seconds without damage. If frequent overload tripping occurs, the load calculation should be checked or the unit should be upgraded.