T & T Inspection Engineering provides Preventive Maintenance, Energy Conservation and Leakage Detection Services

Electrical anomaly / failure symptom will become catastrophic if left unattended. Electrical failure symptom will causes electrical short circuit (phase to phase, phase to ground) power tripping / interruption, discoloration / burn mark / sting smell at the electrical component, high electrical billing and production disturbance; more over a catastrophic electrical power failure will lead to, fire, damage to equipment and property, or loss of life.

The introduction of the predictive maintenance via NDT technologies (infrared thermography, acoustic ultrasound, EMF partial discharge locating, power quality measurement, high & low frequency vibration monitoring, power solution and etc) are able to detect, monitor and trigger for an appropriate time to repair / countermeasure on a specific equipment to reduce the total system failure and loss, maximize the usage and economic value of the equipment, provide sufficient time management for proper schedule shut down / repair, as well as, to reduce the repair and resuming cost of the related equipment.

A.    High Voltage Electrical Equipment (over 1000V AC)

• a. Type of Equipment:
  

  i.	Circuit breaker – Vacuum (VCB), SF6 Gas (GIS), Oil (OCB)
  ii.	Ring Main Unit – SF6 Gas, Oil
  iii.	Power Transformer – 6.6kV, 11kV, 22kV, 33kV, 132kV, etc
  iv.	High voltage cable – 11kV, 33kV, 132kV, etc
  v.	Overhead line and pole, etc

• b. Failure mode
  

  i.	Corona partial discharge
  ii.	Tracking partial discharge
  iii.	Arcing partial discharge
  iv.	Partial discharge causes by high moisture / acidic environment
  v.	Insulation component damage / crack / aging
  vi.	Overloading / under rating
  vii.	Mechanical vibration due to looseness
  viii.	Power quality issue – harmonics / swell & sag, flicker
  ix.	Poor workmanship / improper material
  x.	Etc.

B.    Low Voltage Electrical Equipment (50V~1000V AC)

• a.    Type of Equipment
  

  i.	Main switch board (MSB), Sub-switch board (SSB), distribution board (DB), sub-distribution board (Sub-DB)
  ii.	Circuit breaker – Air circuit breaker (ACB), molded circuit breaker (MCCB), mini circuit breaker (MCB), ELCB, RCCB, etc.
  iii.	Thermal overload relay / timer control
  iv.	Contact switch / control
  v.	Capacitor bank / reactor
  vi.	Low voltage transformer / Auto Transformer
  vii.	Cable and wiring
  viii.	Etc.

• b.    Failure mode
  

  i.	Bad connection / contact
  ii.	Overloading / under rating
  iii.	Malfunction / crack / damage due to aging
  iv.	Oxidization due to high moisture condition / low quality component
  v.	Power quality issue – harmonics / swell & sag, flicker
  vi.	Poor workmanship
  vii.	Etc.

C.    Extra Low Voltage Electrical Equipment (< 50V AC)

• a.    Type of Equipment:
  

  i.	Electronic Printed Circuit Board Assembly (PCB)
  ii.	Battery Bank
  iii.	Integrated Circuit Board (IC)
  iv.	Resistor
  v.	Jumper & wiring
  vi.	Etc.

• b.    Failure mode
  

  i.	Defective component
  ii.	Bad connection
  iii.	Low voltage battery
  iv.	Overloading / under rating
  v.	Poor workmanship
  vi.	Etc.

Samples of Electrical Failure – Infrared Thermography

Faulty at breaker cast resin potential transformer

Bad connection at transformer bushing connection

Bad cable bushing connection at switchgear

Bad cable connection at breaker’s cable compartment

Burn control cable connection

Burn cable at the air-cond panel thermal overload relay

Samples of Electrical Failure – Ultrasound

Partial discharge due to insulation deterioration

Partial discharge due to high moisture environment

Samples of Electrical Failure – Partial Discharge Locating

Partial discharge mapping