Preventive Maintenance, Testing & Commissioning of High and Low Voltage Substation Equipment

Tan Delta Electric Corporation has been providing engineering services for 23 years since 1995 and it focused on specialized engineering works such as Preventive Maintenance, Testing and Commissioning of HV and LV Substation up to 500kV.

Our team is composed of experienced electrical engineers that provide the best service through the use of highly innovative electrical test equipment, execute the measures using technologies, systems, and work processes that give optimal results to our clients.


AC Dielectric Withstand Test up to 500kV

Air and Structure Born Ultrasonic detection for(Motors, Air & Gas Leaks, Corona)

AC VLF /DC High Potential Leakage Current Test

Battery Capacity Discharge & Quality Test

Cable Partial Discharge Test

Contact Resistance Test

Circuit Breaker Analysis (Timing and Motion Test)

DIRANA (Dielectric Response Analysis)

Earth/Ground Resistance/Soil Resistivity Measurement

Instrument Transformer (CT/PT/CCVT) Test

Insulation Power Factor/Tan Delta Test

Insulation Resistance Test

Generator/Motor Phase Resolved Partial Discharge Test

Lightning Arrester Leakage Current Test

Oil Dielectric Breakdown Voltage (DBV) Test

Partial Discharge Analysis and Fault Location for Power Transformers

Partial Discharge Test of GIS

Power Quality Analysis

Protective Relay Testing and Calibration

Sweep Frequency Response Analysis (SFRA)

SF6 Gas Analysis (Moisture, Purity, SO2)

SF6 Gas Recovery

SF6 Gas Leak Detection

Surge Comparison test (Motors & Generators)

Tap Changer Analysis (Dynamic Resistance & AC Ripple Test)

Transformer Turns Ratio (TTR) Test

Winding Resistance Test

Transformer Hauling, Assembly, Repair, Testing and Commissioning

- Transformer Assembly, Repair & Maintenance
- 500 KV Switchyard Maintenance & Testing
- Transformer Oil Leak Repair

Transformer Oil Laboratory Services

Tan Delta Electric Corporation has its own Oil Testing Laboratory to conduct various tests to ensure reliability of the transformer oil.

We offer technologies, methods, and services that address the entire solution for insulating oil.


Type of Test ASTM / IEC Method
 Acidity / Neutralization Number  D664
 Color and Visual Examination  D1500 / D1524
 Corrosive Sulfur  D1275B
 Degree of Polymerization (DP) of Cellulose  D4243
 Dielectric Breakdown Voltage (DBV) Test  D877/D1816/IEC156
 Dissolved gas Analysis (DGA)  D3612A / 60657
 Fire Point / Flash Point  D92
 Furan Analysis (5-Furanic Compounds)  D5837
 Interfacial Tension (IFT) Test  D971
 Kinematic Vicosity  D445
 Liquid Power Factor Test  D924 / 61620
 Metal Passivator
 Oil Conductivity/Resistivity/Dielectric Constant  IEC61620
 Oxidation Inhibitor Content  D2668
 PCB Test  EPA
 Particle Count Analysis  ISO 4406
 Relative Density (Specific Gravity)  D1298
 Soluble Sludge  D1698
 Total Sediments  D1698
 Water-in-Oil Analysis by Karl Fischer  D1533B
Infrared/ Thermal Scanning Services

Thermal scanning is one of the preemptive methods used by Tan Delta Electric Corporation for preventive maintenance of different electrical equipment. It plays a big role in avoiding future electrical equipment failure.

Thermal heating, also known as hotspot, affects the insulation of wires and it could result to oxidation due to excessive heating. If neglected, it can cause a major factor that could affect the operation of the whole electrical system.

Tan Delta Electric Corporation is one of the pioneer in the application of infrared/thermal scanning services in the Philippines, having a U.S. trained Certified Level 1 & 2 Thermographer and licensed engineers with extensive experience in various electrical and mechanical equipment and/or installations.

Electrical System

Mechanical System

Building Inspection

Manufacturing Process



Energy Audits

Air & Structure borne Ultrasonic Inspection Services

UDT (Ultrasonic Detection Testing) is your first line of defense against unplanned downtime. Electrical faults such as arcing, tracking and corona discharge emit ultrasound signals at the site of the failure, often without generating any heat. The use of it is to hear what you cannot see.

It can detect partial discharge at its infancy before it advances to an arcing or tracking condition. Tan Delta Electric Corporation pioneered in year 2002 the application of Ultrasonic Detection services in the Philippines. Inspection is being carried-out by our in-house engineer and certified Level -1 Ultrasonic Inspector trained in the U.S.

Leak Detection (Compressed Air & Gasses)

Bearing Condition Monitoring

Ultrasound Based Lubrication

Steam Trap Inspection

Valves and Hydraulics

Pump Cavitation

Boiler, Heat Exchangers, and Condenser Leaks

Electrical Corona Discharge

Tightness Integrity – Wind Noise & Water Leak


Online And Offline Vacuum Oil Purification And Regeneration Services

Tan Delta Electric Corporation vacuum oil purification and regeneration rigs can be used to process oil on online or offline transformers. Our rigs can process up to 6000 Liters Per Hour, and because the transformer is energized, the customer never has to take an outage

We offer oil regeneration where oil is being restored to its original properties and to be used equally “as new” so replacement is not necessary. Regenerated transformer oil is the best quality, environmental and economic choice for transformer installation and maintenance.

Testing Equipment Repair and Calibration Services

Tan Delta Electric Corporation has its own Repair and Calibration group composed of skilled electronic specialists who ensures that your equipment is accurate and calibrated through the use of highly technical calibration devices and modern software.

Calibration improves the accuracy of the measuring and testing equipment.

- Electrical
- Pressure
- Temperature

Lightning Protection and Grounding Solution

Our lightning protection products includes Exothermic Welding (E plus Series) and Resistance Reducing Agent. For our grounding solution includes Copper Bonded Steel Rod, Clamp, and other grounding accessories.

A good grounding system provides certain level of safety to humans and properties in case of equipment damages.

Training and Technical Support

Our training and technical support facilities is so far the most complete in the Philippines, with a wide ray of test specimens (138kV and 69kV Power Transformer, CVT, CT, PT, SF6, Power CB, LA, Bushing CT, Protection relays and others) and electrical testing equipment.

The facility also houses our transformer oil processing equipment such as vacuum oil purifiers, oil regeneration system and SF6 gas recovery equipment.