Complete Guide to Dry-Type Transformer Installation and Maintenance: Key Steps to Ensure Safe and Stable Operation

As a critical component of modern power systems, proper installation and standardized maintenance of dry-type transformers are essential to ensure safe and stable operation. This article provides a detailed guide to dry-type transformer installation and maintenance.

1. Pre-Installation Preparations

1. Environmental Assessment
   • Ensure the installation site is well-ventilated with an ambient temperature not exceeding 40°C.
   • Control relative humidity to below 90% (at 25°C).
   • Avoid dusty, corrosive, or highly vibrating environments.
2. Foundation Construction
   • The base platform should be level and sturdy with a load-bearing capacity of ≥600 kg/m².
   • Reserve sufficient maintenance space: front ≥1.5 m, sides ≥1.2 m.
   • Grounding system resistance value ≤4 Ω.

2. Detailed Installation Steps

1. Positioning and Installation
   • Use dedicated lifting equipment; strictly avoid pulling coil leads.
   • Check that the transformer tilt is ≤2° after positioning.
   • Install shock absorbers if required.
2. Electrical Connections
   • Thoroughly clean terminal connections before wiring.
   • Use a torque wrench to tighten connection bolts.
   • Recommended torque values: M12 bolts 35 N·m, M16 bolts 80 N·m.
3. Auxiliary Equipment Installation
   • The temperature controller should be positioned to accurately reflect winding temperature.
   • Fan installation direction must align with design requirements.
   • Use flame-retardant cables for all wiring.

3. Commissioning and Acceptance

1. Insulation Testing
   • Use a 2500V megohmmeter to measure insulation resistance.
   • High-voltage to ground ≥300 MΩ, low-voltage to ground ≥100 MΩ.
   • Absorption ratio (R60″/R15″) ≥1.3.
2. No-Load Test
   • Operate at rated voltage under no-load conditions for 24 hours.
   • Measure no-load losses and no-load current.
   • Check noise level ≤65 dB.

4. Daily Maintenance Points

1. Regular Inspections
   • Daily: Record operating temperature and load current.
   • Weekly: Check fan operation status.
   • Monthly: Clean dust from insulation surfaces.
2. Preventive Testing
   • Every 6 months: Insulation resistance test.
   • Annually: Winding DC resistance test.
   • Every 3 years: Comprehensive preventive testing.

5. Common Troubleshooting

1. Abnormal Temperature Rise
   • Check fan operation status.
   • Clean heat dissipation channels.
   • Inspect load balance.
2. Insulation Failure
   • Immediately power off for repair.
   • Measure insulation resistance.
   • Contact professional maintenance personnel.

6. Recommendations to Extend Lifespan

1. Load Management
   • Recommended long-term operating load rate ≤85%.
   • Avoid sudden short-circuit impacts.
   • Balance three-phase loads.
2. Environmental Control
   • Install air conditioning to maintain constant temperature and humidity.
   • Regularly clean dust.
   • Prevent small animals from entering.

7. Safety Precautions

1. Operational Safety
   • Wait 30 minutes after power outage before operation.
   • Verify no voltage with a voltage tester.
   • Display warning signs.
2. Fire Protection Measures
   • Equip with carbon dioxide fire extinguishers.
   • Prohibit the use of dry powder fire extinguishers.
   • Install smoke detection devices.

Conclusion

Proper installation and standardized maintenance are key to ensuring the safe and stable operation of dry-type transformers. By implementing the guidelines provided in this article, not only can the service life of the equipment be extended, but power supply reliability can also be significantly improved. It is recommended to establish comprehensive equipment records documenting all installation and maintenance data to support future maintenance.