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Preventive Maintenance
Plan routine checks, annual service and condition-triggered work by transformer type.
View maintenance planner →Choose Your Support Path
Start with what the transformer needs now
Use the page as an operating guide: plan maintenance, review equipment condition, investigate an abnormal sign or prepare a service request.
Condition Monitoring
Use DGA, oil tests, thermography, partial discharge, vibration and temperature trends.
Review monitoring methods →Troubleshooting
Begin with the observed symptom and check the most relevant operating conditions.
Select an abnormal sign →Parts & Technical Support
Identify replacement parts and prepare the information needed for remote or on-site support.
Prepare a support request →Maintenance by Transformer Type
Focus maintenance on the installed technology
Each transformer type has a different maintenance priority. Use the supplied O&M manual for model-specific procedures.
Oil-Immersed Transformer
Maintain the insulating liquid, sealing system, bushings, cooling equipment, breathers and tap equipment as one connected reliability system.
Oil condition and DGAOil level and leakageBushings and connectionsRadiators, fans and pumpsBreather and desiccantTap equipment and protection
Maintenance principle: set task frequency according to equipment criticality, operating history, load, environment, condition trends and the product maintenance procedure.
01 · Preventive Maintenance Planner
Combine scheduled work with condition-based decisions
Use a baseline annual program, then increase or adjust maintenance when operating data, environment or equipment condition changes.
Observe the Running Unit
- Load, voltage and temperature
- Oil level and visible leakage
- Sound and vibration
- Fan, pump and alarm status
- Access, enclosure and surroundings
Preventive Maintenance
- Inspect pumps, fans and cooling controls
- Clean bushings and insulation surfaces
- Review oil condition where applicable
- Check seals, level and breather
- Inspect connections and ventilation
Increase Attention
- DGA or oil trend changes
- Hot spots or rising temperature
- Leakage, moisture or corrosion
- Abnormal noise or vibration
- Cooling-system performance decline
Plan by Risk & History
- Cooling and tap mechanism service
- Protection-device calibration
- Internal inspection when condition requires
- Coating and corrosion repair
- Major component replacement
No single interval fits every transformer. Major-service scope is determined by equipment criticality, operating history, loading, environment, condition trends and the approved maintenance procedure.
02 · Condition Monitoring
Use trends to identify developing problems early
One result is a snapshot. Repeated measurements under comparable conditions reveal the operating trend that supports maintenance decisions.
Dissolved Gas Analysis
ChecksChanges in gases dissolved in insulating oil.
Warning signalAbnormal concentration, rate of change or gas pattern.
ActionReview the trend and increase sampling or diagnosis under the maintenance procedure.
Oil Quality
ChecksDielectric strength, moisture, acid value and visual condition.
Warning signalReduced breakdown strength or rising moisture/acidity.
ActionConfirm sampling quality and assess filtration, treatment or further investigation.
Infrared Thermography
ChecksTerminals, bushings, joints and cooling components.
Warning signalLocal temperature difference or rising thermal trend.
ActionReview load, connection condition and cooling performance.
Partial Discharge
ChecksLocalized electrical discharge activity in insulation.
Warning signalIncreasing magnitude, repetition or pattern change.
ActionCorrelate with other data and obtain specialist insulation assessment.
Vibration & Noise
ChecksCore, winding, structural and auxiliary-equipment behavior.
Warning signalA new tone, rising level or load-dependent change.
ActionCompare with the operating baseline and inspect mechanical and electrical causes.
Temperature Trending
ChecksWinding, oil, ambient and cooling-stage response.
Warning signalHigher temperature at the same load or delayed cooling response.
ActionReview load, ambient conditions, ventilation and cooling operation.
03 · Troubleshooting by Symptom
Start with the abnormal sign you can observe
Select a symptom to see the first operating conditions to review. Internal inspection or repair must be performed by qualified service personnel.
Overheating
Review loading, ambient conditions and heat-removal performance before deciding the next maintenance action.
Compare load with rated capacityCheck ambient temperature and ventilationConfirm fans, pumps and radiators operateInspect connections with thermal imagingReview harmonic loadingCheck temperature sensors and alarms
Stop and escalate when safety is at risk.Do not open the tank, dismantle energized components, alter protection settings or operate a non-loadbreak device under load. Follow the approved isolation procedure and contact qualified service personnel.
04 · Harsh-Environment Care
Adapt maintenance to climate and site exposure
Environmental conditions change the inspection focus, seasonal preparation and protective maintenance required.
Coastal & High Humidity
Prioritize moisture exclusion and corrosion control.
- Inspect seals and cable entries
- Check breathers and desiccant
- Monitor oil moisture where applicable
- Inspect coatings and early rust
- Keep ventilation paths clear
RAINY-SEASON CHECKSALT-SPRAY CARE
Extreme Cold
Prepare sealing, oil, controls and auxiliary systems for low temperature.
- Inspect seals and material condition
- Check oil level and low-temperature behavior
- Verify heaters and controller protection
- Follow the cold-start procedure
- Prepare cold-rated replacement parts
PRE-WINTER SERVICECOLD START
Hot, Dusty or Tropical
Protect cooling performance and drainage.
- Clean radiators and air passages
- Inspect fans, pumps and controls
- Remove dust, insects and vegetation
- Check drainage before rainy periods
- Inspect sealing before high humidity
HOT-SEASON CLEANINGDRAINAGE CHECK
05 · Spare Parts & Technical Support
Identify the transformer and part before ordering
Accurate nameplate information, photographs and a clear part description help YAWEI identify the correct replacement and support path.
Describe the PartPart name, function and reason for replacement.
Provide Nameplate DataTransformer type, kVA, primary/secondary voltage and serial number.
Add PhotosOverall unit, nameplate, installed part and connection details.
Explain the ConditionAlarm, failure symptom, damage or planned replacement need.
Confirm Delivery NeedProject location, required quantity and target date.
06 · Warranty & Service Request
Provide the information needed for an efficient technical assessment
A complete request helps the support team understand the equipment, operating condition and required response.
Identify Equipment
Order or contract, model, serial number, kVA and voltage.
Describe the Issue
Operating condition, start time, symptoms and recent changes.
Attach Evidence
Photos, videos, alarms, protection records and test results.
Technical Assessment
Remote review determines immediate actions and information gaps.
Support Plan
Parts, guidance, site service or corrective work as appropriate.
Project-defined warranty and service termsWarranty scope, start date, duration, exclusions, response arrangements, on-site service and parts responsibility are defined in the project contract and service plan.
YAWEI after-sales technical support
Need help maintaining or troubleshooting a transformer?
Send the nameplate details, operating condition, alarms, photographs and available test data so our team can review the next support step.