Ceramic – Transformator bushings – 3 kV – DIN42539

Transformator bushings

Ceramic / porcelain material

					Ceramic group	Ceramic group	Ceramic group	Ceramic group
				Sub-Group	C-110	C-120	C-130	C-221
					Silicious Porcelain	Aluminous porcelain Standard strength	Aluminous porcelain High strength	Steatite low/loss angle
Properties	Properties	Properties	Symbols	Units	AL2O3 <30%	AL2O3 30-50%	AL2O3 >50%
Apparent prosity (open)	max.	max.	Pa	Volume %	0.0	0.0	0.0	0.0
Bulk density	min.	min.	δa	g/cm3	2,2	2,3	2,5	2,7
Flexural strength	min.	unglazed	Rf	N/mm2	50	90	140	140
	min.	glazed	Rf	N/mm2	60	110	160	-
Modulus of elasticity		min	E	GPa	60	70	100	100
Mean coefficient linear expansion			α 20-100°C	10-6K-1	3-6	3-6	4-7	6-8
			α 20-300°C	10-6K-1	3-6	3-6	5-7	7-9
			α 20-600°C	10-6K-1	4-7	5-7	5-7	8-9
Specific heat capacity		20°-100°C	cp	J/kgK	750÷900	750÷900	750÷900	790÷920
Thermal conductivity		20°-100°C	λ	W/mK	1÷2,5	1,2÷2,6	1,5÷4,0	2,3÷2,8
Resistance to thermal shock		min.	Δt	K	150	150	150	100
Electric strength		min.	Ed	kV/mm	20	20	20	20
Withstand voltage		min.	U	kV	30	30	30	30
Relative permittivity		48÷62 Hz	εr		6÷7	6÷7	6÷7,5	6
Dissipational 20°C	max.	48÷62 Hz	tanδ	10-3	25	25	30	1,5
	max.	1 kHz	tanδ	10-3	-	-	-	-
	max.	1 MHz	tanδ	10-3	12	12	15	1,2
Volume resistivity in terms of temperature	min.	20°C	ρv	Ωcm	1013	1013	1013	1012
	min.	200°C	ρv	Ωcm	108	108	108	1011
	min.	600°C	ρv	Ωcm	104	104	104	107
Temperature corresponding to a volume resistivity	min.	100 MΩcm	tK100	°C	200	200	200	500
	min.	1 MΩcm	tK1	°C	350	350	350	800

For post insulators, hot-dip galvanized cast iron flanges assembled or with :
Sulphur cement = excellent mechanical performances and max use temperature 90°C - Reduced assembly time
Portland cement = max use temperature 200°C - Drying time in mould is longer

Ceramic transformator bushing 3 kV

Ceramic transformer bushings - DIN42539 - Part A

DIN42539 - Part A	For bushing	Fig.	1	2	3	4	H	Cr	A	d1	d2 e2	d3	d4	e1	h1	h2	Weight
	type		kV	kV	kV	kV	mm	mm		mm	mm	mm	mm	mm	mm	mm	kg

DT3-250A	DT3-250	A	3	28	40	70	135	120	250	14	37	32	75	60	85	-	0,40
DT3-630A	DT3-630	A	3	28	40	70	135	120	630	22	43	47	90	70	85	-	0,60
DT3-1000A	DT3-1000	A	3	28	40	70	135	125	1000	32	53	65	110	90	85	-	1,00
DT3-2000A	DT3-2000	A	3	28	40	70	135	125	2000	44	66	80	125	105	85	-	1,40
DT3-3150A	DT3-3150	A	3	28	40	70	135	125	3150	50	86	100	145	125	85	-	2,00

Ceramic transformer bushings - DIN42539 - Part B

DIN42539 - Part B	For bushing	Fig.	1	2	3	4	H	Cr	A	d1	d2 e2	d3	d4	e1	h1	h2	Weight
	type		kV	kV	kV	kV	mm	mm		mm	mm	mm	mm	mm	mm	mm	kg

DT3-250B	DT3-250	B	3	28	40	70	55	120	250	40	60	26	70	20	45	10	0,30
DT3-630B	DT3-630	B	3	28	40	70	55	120	630	46	70	41	85	28	45	10	0,30
DT3-1000B	DT3-1000	B	3	28	40	70	55	125	1000	57	90	46	110	37	45	10	0,60
DT3-2000B	DT3-2000	B	3	28	40	70	55	125	2000	70	105	64	125	51	45	10	0,70
DT3-3150B	DT3-3150	B	3	28	40	70	55	125	3150	90	125	80	150	61	45	10	1,00

1 - Rated Highest voltage for equipment (Um)
2 - Rated Power Frequency Withstand Voltage, wet (50 Hz, 1 min)
3 - Rated Power Frequency Withstand Voltage, dry (50 Hz, 1 min)
4 - Rated Lightning impulse withstand, dry (1.2/50 μs)
Cr - Minimum creepage length
A - Rated Current

Monday	8am > 4:30pm
Tuesday	8am > 4:30pm
Wendsday	8am > 4:30pm
Thursday	8am > 4:30pm
Friday	8am > 12am
Saturday	Closed
Sunday	Closed