Indoor single-phase epoxy resin casting current transformer complying with GB/T20840.1/2 and IEC61869-1/2 standards; rated insulation level 40.5/95/185kV, rated frequency 50/60Hz, rated secondary current 5A or 1A. Optional primary current covers 300–3150A; accuracy-class rated outputs:10-30VA(0.2S/0.5S),15-30VA(0.5),10-30VA(5P10),10-30VA(5P20); short-time thermal current ranges 31.5–100kA, rated dynamic stable current ranges 80–160kA; product weight:91kg; ambient operating temperature -5℃~+40℃.
Indoor 35kV class current transformer for medium-voltage switchgear, suitable for metering and protection up to 40.5kV systems.
| Parameter | Specification | Verification |
|---|---|---|
| Product Type | Current Transformer | [On Request] |
| Model Code | LDZB7-35 | Factory nameplate marking |
| Primary Voltage | 20kV | Rated voltage test (IEC 61869-1/3) |
| Secondary Voltage | 5A/1A | Ratio check at rated frequency |
| Accuracy Class | [On Request] | Accuracy test (IEC 61869-2 / IEEE C57.13) |
| Rated Burden | [On Request] | Burden test at rated VA |
| Insulation Type | Dry Epoxy Resin | Dielectric tests per standard |
| Insulation Level (BIL) | 24/65/125kV | Power-frequency & lightning impulse withstand |
| Standards | [On Request] | Certified to listed standards |
| Frequency | 50/60Hz | Per IEC 61869-1 |
| Environment | Ambient: -5℃~+40℃ | Per datasheet limits |
Ideal For
Not Recommended For
Connect primary through the bushing. Secondary terminals: 1S1/1S2 for metering, 2S1/2S2 for protection. Never open-circuit the secondary of a CT while energized - hazardous voltage. Ground the secondary winding at one point. Follow IEC 61869-2 terminal markings.
Compliant with: [On Request]
S_total = ΣS_instrument + I₂² × (ρ × 2L / A)
Q: What is the insulation level of this CT?
A: The rated insulation level is 40.5/95/185kV, meaning 40.5kV system voltage, 95kV power-frequency withstand, and 185kV lightning impulse withstand.
Q: What accuracy classes are available?
A: Optional accuracy classes include 0.2S/0.5S for metering and 5P10/5P20 for protection, with rated outputs from 10-30VA.
Q: Can this CT be used outdoors?
A: No, it is designed for indoor use only. Outdoor installation would require additional weatherproofing.
Missing fields are marked [On Request] — never fabricated. M2/M5/M6 verification rows follow IEC 61869 / IEEE C57.13 conventions.
| Rated primary current I1n (A) | Accuracy classCombined | 0.2(S)/0.5(S) | 0.5 | 5P10 | 5P20 | Short-time thermal current Ith (kA/S) | Rated dynamic current Idyn (kA) | Weight (kg) |
|---|---|---|---|---|---|---|---|---|
| 300 | 0.2(S)/0.5(S)/5P/5P 0.2(S)/5P/5P/5P 0.5(S)/5P/5P/5P | 10 | 15 | 15 | 10 | 31.5 | 80 | 91 |
| 400 | 0.2(S)/0.5(S)/5P/5P 0.2(S)/5P/5P/5P 0.5(S)/5P/5P/5P | 10 | 15 | 20 | 15 | 45 | 112.5 | 91 |
| 500 | 0.2(S)/0.5(S)/5P/5P 0.2(S)/5P/5P/5P 0.5(S)/5P/5P/5P | 20 | 25 | 15 | 20 | 53 | 130 | 91 |
| 600 | 0.2(S)/0.5(S)/5P/5P 0.2(S)/5P/5P/5P 0.5(S)/5P/5P/5P | 30 | 30 | 30 | 30 | 80 | 160 | 91 |
| 800 | 0.2(S)/0.5(S)/5P/5P 0.2(S)/5P/5P/5P 0.5(S)/5P/5P/5P | 30 | 30 | 30 | 30 | 80 | 160 | 91 |
| 1000-1200 | 0.2(S)/0.5(S)/5P/5P 0.2(S)/5P/5P/5P 0.5(S)/5P/5P/5P | 30 | 30 | 30 | 30 | 100 | 160 | 91 |
| 1500-3150 | 0.2(S)/0.5(S)/5P/5P 0.2(S)/5P/5P/5P 0.5(S)/5P/5P/5P | 30 | 30 | 30 | 30 | 100 | 160 | 91 |
Dimension & outline drawing of LDZB7-35 — click image to zoom / view original.
