High PD activity ...
... lead to uncovering a critical problem - the incorrectly installed wedges
Company: Midwest US Utility
Ratings: 173 MW, 18 kV, Hydrogen Cooled Turbine Generator, 3 years in operation
Manufacturer: Confidential
Related Info: 25 years old
PD Sensors: Two bus couplers per phase
Case Study Details:"... With the high H2 pressure (30-35 psig) the [PD] levels were expected to be very low but instead were very high after only a year of operation. We initially expected to find problems with the couplers as we did not believe the results..."
High PD activity (slot discharge)...
...was a foresign of an upcoming failure
Company: Western Canadian Utility
Ratings: 184 MVA, 13.8 kV, Air Cooled Hydro Generator
Manufacturer: Confidential
Related Info: 25 years old
PD Sensors: Four PDA Couplers per phase
Case Study Details: The PD data for this unit has been trended for over ten years. In 1995, semi-conducting paint and CRTV were injected into selected bars ...
Intelligent on-line signature analysis...
...revealed broken rotor bars
Company: A large utility in the US northeast
Ratings: 3000hp, 6.6kV 1785rpm Motor
Manufacturer: Confidential
Case Study Details: The suspicion arose from a constant hum during motor operation and abnormal vibration levels during start-up and running. The plant vibration monitoring system did not have the ability to zoom...
High level system PD noise...
...uncovered a well-developed tracking
Company: Italian utility
Ratings: 390 MW, 20kV, Hydrogen Cooled Turbine Generator
Manufacturer: Confidential
Related Info: Installed in 1970
PD Sensors: Two Bus Couplers per phase
Case Study Details: During a partial discharge measurement using the TGA-B portable instrument, high levels of PD activity (over 3000mV position, well above the highest range, see Figure 1) were detected on the C phase outside...
Reading Instability...
...uncovered internal bad connection on a new transformer
Company: US North-West utility
Ratings: 45 MVA power transformer
Manufacturer: Confidential
A customer was commissioning a new 45 MVA power transformer delivered by an overseas manufacturer. During the test, ADWEL's Digital Winding Resistance ReporteR, DWR-10, was consistently issuing a warning of current interruptions, and did not complete the test. Another DWR-10 instrument was used with similar outcome. All other standard measurements, including TTR, Tan-Delta and insulation resistance indicated acceptable resistance value.
Nevertheless, the customer drained the oil and inspected the transformer to detect that the windings on all 3 phases were not properly secured to the bushings. Had the transformer been energized, a catastrophic failure could have occurred.
IRIS Power UK
Acorn House
Greenhill Crescent
Watford WD18 8AH, UK
Attention: Office Administrator
Phone: +44 (0) 1923-254433
Fax:+44 (0) 1923-218278
E-mail: info@irispower.co.uk
ADWEL International Ltd will include documentation that will advise customs of the cost of the service in the return shipment.
A copy of the return shipment air way bill/bill of lading will be faxed to you for tracking purposes
EQUIPMENT |
INTRASTAT CLASSIFICATION CODE |
COUNTRY OF ORIGIN |
|
T&D Instruments (recording)
DWR/DRR/TeraOhm |
9030 89 20
|
Canada
|
|
T&D Instruments (all others)
|
9030 39 20
|
Canada
|
|
T&D Accessories and Spares
|
9030 90 85
|
Canada
|
|
Digital EL CID and Upgrades
|
9030 89 20
|
UK
|
|
RIV-701
|
9033 00 00
|
UK
|
| Camera 752 | 9031 49 00 | UK |
| MCT-2 | 9030 39 20 | UK |
| EL CID, MCT-2, RIV, Camera Accessories and Spares | 9030 90 85 | UK |
| WTD-501 and 523 | 9030 89 20 | Canada |
| DCR-50 | 9030 89 20 | Canada |
| PDA Premium, COPA, STB-3 nd Premium Upgrades | 9030 39 20 | Canada |
| PPM 97 Corona Probe | 9030 39 20 | Canada |
| PDA Couplers and Accessories | 8535 90 00 | Canada |
| WTD, PDA and DCR Instrument Spares and Accessories | 9030 90 85 | |
| Magnastart | 8504 50 95 | UK |
| Repair and Calibration | Use same code as if the item was sold |
When declared to customs in the European Community, goods must generally be classified according to the Combined Nomenclature or CN. Imported and exported goods have to be declared stating under which subheading of the nomenclature they fall. This determines which rate of customs duty applies and how the goods are treated for statistical purposes. The CN that classifies goods at 8-digit level has been in use as an integrated classification for both Duty purposes and for trade statistics since 1 January 1988.
The CN is also used in intra-Community trade statistics. For extra-EC trade the Integrated Tariff of the United Kingdom, adapted from the CN, must be used for both imported and exported goods.
The CN is comprised of the Harmonized System (HS) nomenclature for the first 6 digits with further Community subdivisions. The Harmonized System is run by the World Customs Organisation (WCO). This systematic list of commodities forms the basis for international trade negotiations, and is applied by most trading nations.
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