Page 58 - Website 119

U¼b¹b% ‚dÞË UNÐU³Ý√Ë –UHM�« ô“UFÐ UNŁËbŠ qL²;« ‰UDŽ_« ∫©µ® r�— ‰Ëbł
qDF�« b¹b% ‚dÞ qDF�« »U³Ý¬ qDF�« Ÿu‡½
Methods of Detection Possible Results Kind of Failure
-Visual Inspection. -Moisture Enters. 5KÝ—u³�UÐ Œdý
-Power Factor Test. -Oil and/or Gas leaks . Cracked Porcelain.
-Hot - Collar Test. -Filler Leaks Out.
-Visual Inspection. -Moisture Enters. ‰UBðô« ◊UIMÐ ÂœUIð
-Power Factor Test. -Oil and/or Gas leaks . Deterioration of Cemented
-Hot - Collar Test. -Filler Leaks Out. joints.
-Visual Inspection. -Moisture Enters. U½«u'UÐ V¹d�ð
-Power Factor Test. -Oil and/or Gas leaks . Gasket Leaks.
-Hot - Collar Test. -Filler Leaks Out.
-Hot - Wire Test. …—bI�« q�UF�Ë ©θ® 5Ð W�öF�« ∫©≥® r�— ‰Ëbł
-Insulation Resistance.
• (pf) …—bI�« q�UF� ©θ®
-Power Factor Test. -Moisture Enters. ‰eF�« w� WÐuÞ—
-Hot - Collar Test. Moisture in Insulation. dH� π∞
-Visual Inspection. -Moisture Enters. U�U×K�« v� V¹d�ð ∞[≥¥π ∏π[∏
-Power Factor Test. -Filler Leaks Out. Solder Seal Leak. ±[∑µ
-Hot - Collar Test. ∏π[µ
-Hot - Wire Test. ≥[¥π ∏∏
-Leak Detector.
µ[≤≥ ∏∑
-Power Factor Test. -Spark in Apparatus Tank or Within WHA�«Ë i¹—Q²�« W³Kł 5Ð WK�u�« d�� ∏[∑±
-Dissolved Gan in Oil Analysis. Bushing. Broken Connection Between ∏∂
-Thermographic Scanning. -Discolred Oil. Ground Sleeve and Flange.
-Hot - Collar Test. -Internal Corona. ‰“UF�« jOK)« v� Už«d� œułË
-Power Factor Test. Voids in Compound. ÆÆ©Test Tap® WF?��« ”UO� WDI½Ë w?�Ozd�« q�u*«
-Visual Inspection. -Filler Contamination. X¹e�« ‰U%—« W{—R*« dOž W¹UNM�«Ë …—bI�« q�UF� ”UO� WDI½ p�c�Ë
-Power Factor Test. Oil Migration. V�d� ‰“UŽ Í√ vKŽ WI¹dD�« Ác¼ Íd&Ë Æ–UHM�« ‰“UF�
-Hot - Collar Test.
·dDÐ Ë√ ”UO� WDIMÐ «œËe� ÊuJ¹Ë ÆÆUN½ËbÐ Ë√ …bF0
-Visual Inspection. -Oil Leaks Out. X¹“ œułË ÂbŽ WDI½ Í√ 5Ð W�ËUI*« WLO� ÊuJðË Æ÷—_« sŽ ‰ËeF�
-Power Factor Test -Moisture Enters. No Oil.
-Hot - CollarTest ÆÂË√ U−O� ∞[µ ÍËU�¹ Ë√ s� d³�√ ÷—_«Ë ”UO�
-Visual Inspection -Cracked or Broken Porcelain. v×DÝ iO�Ë ∫The Hot-Collar sšU?��« œ«d³�« —U?³²š« W?I¹dÞ ≠¥
-Test Lightning Arresters. -Complete Faiture. Electrical Flashover.
‰“UF�« s� dOG� ¡e' ‰eF�« W ?LO� ”UO� r²¹ ÆÆUNO�Ë
-Power Factor Test. -Internal Breakdown. U½Ë—u� ÀËbŠ wł—U?)« 5KÝ—u³�« ·ö?ž s� ¡e?ł vKŽ√ 5Ð lI¹
-Hot - Collar Test. -Radio Interference. Corona.
-Hot - Wire Test. -Treeing Abng Surface of Paper or ôULJ²?Ý« —U³?²šô« «c¼ d?³²F¹Ë Æv�?Ozd�« q�u*«Ë
-Radio - Influence Voltage Test. Internal Surfaces. W�UŠ w� ôU?F� d³²F¹Ë ÆÆW?IÐU��« WŁö¦�« «—U?³²šö�
-Thermographic Scanning.
-Dissolved Gas in Oil Analysis (DGA). œułË Ë√ 5KÝ—u³�« `D�Ð …œu ?łu*« ŒËdA�« b¹b%
-Power Factor Test. -Increased Capacitance. W¹uF��« UI³D�« w� dB� w� hI½ œułË Ë√ ‰“UF�« s� ÍuKF�« ¡e'« w� ÀuKð
-Voltage Test at Capacitance Tap. -Reduced Voltage at Capacitance Short Circuited Condenser ô Ác¼Ë W�“U?F�« …œU*« w� »uO?Ž Ë√ X¹e�« Èu?²�?�
-Thermographic Scanning. Tap Terminal. Section. ÆWIÐU��« «—U³²šô« w� dNEð
-DGA. -Adds Internal Stress to Insulation.
-Power Factor Test. -Radio Inter Ference. X¹e�« Êu� v� dOGð u‡‡¹œ«d‡�UÐ ‰U‡‡?‡FH�« b‡‡‡N?‡'« —U‡‡‡³²?š« ≠»
-Hot - Collar Test. -Poor Test Results. Darkened Oil. :Radio Influence Voltage (RIV)
WŁœU(« ¢U½Ë—uJ�«¢ qO−�ð sJ1 ÆÆ—U³²šô« «cNÐË
lL?�¹ »UIŁ œu?Ž ‰UF?ý≈ bMŽË ÆÆpK��« vKŽ ‰e?F�« dL²�*« —U?O²�UÐ ‰eF�« W�ËUI� ”UO?� —U³²š« ≠‡ł
ÆÆWÐuÞ— œułË W�UŠ w� …—«dý Àb%Ë d�� u� ∫DC Insulation Resistance n¦J*« d?Ož ŸuM�« s� ô“U?FK� ¢Êe¹d�«¢ WDЗ√ w�
W�U?Š w� «u�√ Í√ ÀËb?Š ÊËœ jOK)« dN?BM¹Ë W×?{u*« WI¹dDK� UI?³Þ Èd−¹Ë ÆÆNon Condenser
ÆƉ“UF�« qš«œ …œu?łu*« WÐuÞd�« b¹b×?²� Èd−¹Ë
∫WÐuÞ— œułË ÂbŽ W??O*U?F�« 5O?zUÐd?NJ?�« ŸUMB�« WDЫ— —«b??�≈ w�
qIð ô√ V−¹Ë Æ· ≤µ∞∞ d ?−?O?� p�c� Âb�?²?�¹Ë …¡uKL*« ô“U?FK� ©RIV® W?LO?� d?³²?FðË ©NEMA®Æ
∫Oil for Moisture X¹e�« w� WÐuÞd�« —U‡³²š« ≠‡¼
ÆÂË√ U−O� n�√ ≤∞ sŽ UN²LO� œułË WO�UL²Š« v�≈ dOAð UNðœU¹“Ë ÆÆWCH�M� X¹e�UÐ
ÂU??L??B�« s� X?¹e�« s� WMO??Ž V?×??Ý r²¹
∫Hot -Wire —U‡‡(« pK‡‡��« —U‡‡³²š« ≠œ ÆX¹e�« Èu²�� w� hI½
(Oil Sampling Valve) p?�c‡?‡?� hB?‡?‡‡?<«
”U?OI� Âb?�²?�¹Ë
≠ ©ASTM® WO*UF�« UH�«u*UÐ ¡Uł U* ÎUI³Þ U¼—U³²š«Ë X¹e�« v� W³z«c�« «“UGK� WM�ü« V�M�« ∫©¥® r�— ‰Ëbł
qš«œ WÐuÞd�« W??³?�½
X¹e�« W?O?L??� …U?Ž«d?� l� ÆÆ(D1533) r�— W?I¹dÞ WO*UF�« WOÝUOI�« UH�«uLK� UI³Þ
vKŽ W¹u?²;« ô“U?F�«
b¹bł X¹eÐ ‰“UF�« ¡q� …œUŽ≈ sJ1Ë Æ‰“UF�UÐ …œułu*« IEEE C 57 - 104 IEC 60599
p�–Ë ÆÆW�“UŽ …œU� jOKš
ÆX¹e�« WOL� ‰ULJ²Ý«Ë ‰“UF�« nOH& Ë√ “dłË— V�½ (ppm) (ppm) (ppm) “U‡‡‡‡‡G�«
qš«œ sšUÝ pKÝ l�bÐ
X¹e‡‡�« w?‡� W‡‡³z«c‡�« «“U‡‡?G�« —U‡‡³?²?š« ≠Ë W�U????Š w�Ë ÆjO?K)« WM�ü« V�M�« qDF�« bŠ s�ü« b(« s�ü« b(«
:Dissolved Gas Analysis (DGA) lL?�¹ ÆÆWÐuÞ— œu?łË 0.1 ≤ CH4/H2 ≤ 1 ≤∞∞ ±∞∞ ±¥∞ H2 5łË—bO¼
b¹b% —U³²š« ¡«dł≈Ë X¹e�« s� WMOŽ V×Ý sJ1Ë Æd?�� Ë√ Œd?ý u� ≤¥∞ ±≤∞ ¥∞ CH4 ÊU‡¦O�
w�Ë Æ‰UF²ýö� WKÐUI�«Ë X¹e�« w� W³z«c�« «“UG�« WOL� œułË ÂbŽ W?�UŠ w� U�√ ≠ ∂µ ∑∞ C2H6 ÊU‡¦¹≈
C2H4 / C2H6 < 1
«“UG�« w�UÐ V�½ w� ŸUHð—« Ë√ 5K² ?Ý√ œułË W�UŠ d?N?BMO?� ÆÆWÐuÞ— Í√ ±∞∞ µ∞ ≥∞ C2H4 5K‡O¦¹≈
Ë …—«d?ý ÀËb?Š v�≈ d?O??A¹ p�– ÊS?� ÆÆÈd?š_« „UM¼Ë ÆU?F¹d?Ý pK��« C2H2 / C2H4 < 0.1 ∑∞ ≥µ ≤ C2H2 Êu²O‡Ý√
h×H�« «¡«dł≈ –U�ð« r²¹Ë Ɖ“UF�« qš«œ ¢U½Ë—u�¢ l{u¹ Èd??š√ W?I¹dÞ ≠ ≥µ∞ ±∞∞∞ CO ÊuÐdJ�« bO��√ ‰Ë√
ÆÆ…œUŽË Æt?�«b�?²Ý« …œU?Ž≈ WO½UJ�≈ b?¹bײ?� Èdš_« jOKš s� iF?Ð UN?O?� ≠ ≠ ≥¥∞∞ CO2 ÊuÐdJ�« bO��√ v½UŁ