Power-Transformer-Testing-Procedures.xls

	A	B	C	D	F	H	I	J	L	N	O	P	R	S	U	V
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2	POWER TRANSFORMER
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4	1	Insulation Resistance Measurement
5		Procedure
6		a.	For LT systems, use only 500V or 1000V Megger.
7		b.	For MV & HV systems, use 2500V or 5000V Megger.
8		c.	Remove Earth from Transformer neutral.
9		d.	Measure as per table below.
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13														Circuit		Megger Used
14																MV & HV
15														1U - E		5kV
16														2U - E		5kV
17														1U - 2U		5kV
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25	2	Winding Resistance Measurement
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28											Circuit			Tap No	Resistance Ω
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30											1U-1N		All Taps
31											1V-1N
32											1W-1N
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34											2U-2N
35											2V-2N
36											2W-2N
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54	3	Magnetic Current Test
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67			Applied Voltage				Measured Current
68			1U-1V				1U
69			1V-1W				1V
70			1W-1U				1W
71			1U-1N, 1V-1N,1W-1N				1N
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73	4	Magnetic Balance Test
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88		Applied Voltage				Measured Voltage
89		1U1N		1V1N	1W1N	1U1N		1V1N	1W1N	2U2N		2V2N	2W2N
90		415		-	-	-
91		-		415	-			-
92		-		-	415				-
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94		Applied Voltage				Measured Voltage
95		1U1V		1V1W	1W1U	1U1V		1V1W	1W1U	2U2V		2V2W	2W2U
96		415		-	-	-
97		-		415	-			-
98		-		-	415				-
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