Dissolved Fault Gas Analysis (DGA)
Abnormal electric and thermal stresses on electrical apparatus are invariably accompanied by degradation of the insulating materials. In oil-paper systems, this degradation leads to the production of a number of gases, collectively referred to as fault gases.
These are principally: hydrogen, carbon monoxide, carbon dioxide and low molecular weight hydrocarbons. The rate of generation and the composition of fault gases is a function of both fault severity and of fault type.
Faults, even in their very early stages, always result in some localized breakdown of the transformer oil.
The amount of oil degraded by even quite severe faults is so small, relative to the total amount of oil in the transformer, that there is no significant or detectable effect on the physical or dielectric properties of the system as a whole. Nevertheless, the breakdown products themselves remain dissolved in the oil and are quickly distributed throughout the transformer.
Detection of such breakdown products gives the earliest possible warning of the existence of an incipient fault in the transformer. Taking routine oil samples from the transformer is therefore an extremely cost efficient way of monitoring its fault gas concentrations under normal operation.
ASTM D 3612 and ISO 60567 solely recognize Gas Chromatography for making reliable DGA measurements. Through compliance with these requirements, PQE’s Portable DGA offers customers traceability, reliability and peace of mind. The complete analytical procedure is described in protocols now recognized worldwide (ASTM D-3612 in America and IEC 599 in Europe and elsewhere). A report will be generated and submitted to customer.
Proper interpretation of these results can save hundreds of thousands of dollars in production and equipment losses!
Gasses measured:
- Hydrogen, H2
- Methane, CH4
- Ethane, C2H6
- Ethylene, C2H4
- Acetylene, C2H2
- Carbon monoxide, CO
- Carbon dioxide, CO2
- Oxygen, O2
- Nitrogen, N2
PQE is using precise and accurate DGA in remote locations or on-site diagnosis 9 gases from the sampled transformer oil.
- Lower detection limit to 1 ppm for Fault gases
- Portable DGA analyzer in compliance with ASTM 3612 Method C or IEC 60567
- No interference from other gases (Freon , SF6)
- No Contamination of the Analysis by CO2 in the Air.
- Used proven HP / Agilent Chromatography technology platform for 15 years with highly accurate and reliable
- Analyze 7 different types of oil
- Gas in Gas analysis from Bucholtz relay or Headspace
COST BENEFITS FOR PERFORMING ONSITE TRANSFORMER OIL TEST
Operating and capital costs as well as consequential damages can be avoided by using PQE’s routine on-site oil analyse regularly:
- Confirm the presence or absence of a fault in a transformer
- Reduce unplanned outages
- Optimize your maintenance schedule
- Better control load on equipment known to have faults
- Prevent equipment failure and production losses
- Monitor / diagnose critical equipment during re-energizing or commissioning
- Monitor / diagnose less critical equipment at a lower cost
Contact our application engineers for further details click here.
