Huaming’s new SDZV vacuum tap-changer was launched to the market, an optimized product based on SHZV, with a better performance in distinguishing arcing and a higher max. rated current of 3000A.
* Adopting the same structure of traditional SHZV tap-changer, SDZV inherits SHZV’s advantages, including inputting force from the head, arranging cables outside the oil compartment and transmitting force in the middle.
* SDZV vacuum tap-changer is equipped with vacuum interrupters with two sets of contacts arranged in series. Two sets work simultaneously, but the arc-distinguishing compartments are relatively independent, both capable of making and breaking.
* The recovery voltage after vacuum interrupters break the current is reduced to previous 1/2, preventing re-ignition.
* When the two sets of contacts break, there are arcs on every contact. After the current is zero, the re-ignition is possible only when there is re-ignition on both contacts, more difficult than the traditional single-set design. As a result, SDZV is more reliable.
* SDZV has a max. rated current of 3000A and max. capacity of 6000V.
Item | Description | SDZVIII | SDZVI |
1 | Max. rated through current (A) | 400 | 600 | 1000 | 1300 | 400 | 600 | 1000 | 1600 | 2400 | 3000 |
2 | Rated frequency (Hz) | 50 or 60 |
3 | Connection | 3-phase Y-connection for neutral point only | Single-phase for any selectable winding connection |
4 | Max. rated step voltage (V) | 6000 |
5 | Rated step capacity | 2250 | 2400 | 4500 | 4950 | 2250 | 2400 | 4500 | 6600 | 8400 | 9000 |
6 | Short-circuit current test (kA) | Thermal (3s) | 6 | 8 | 12 | 15 | 6 | 8 | 12 | 24 | 24 | 30 |
Dynamic (peak) | 15 | 20 | 30 | 37.5 | 15 | 20 | 30 | 60 | 60 | 75 |
7 | Max. operating positions | 35 without change-over selector; 107 with change-over selector |
8 | Insulation to ground | The highest voltage for equipment (kV) | 72.5 | 126 | 170 | 252 |
Rated separate source AC withstand voltage (kV/50Hz,1min) | 140 | 230 | 350 | 460 |
Rated lightning impulse withstand voltage (kV,1.2/50μs | 350 | 550 | 750 | 1050 |
9 | Tap selector | Categorized into B, C, D & DE four sizes |
| Max. working positions | 14 without change-over selector 27 with change-over selector |
10 | Mechanical life | Not less than 1,500,000 operations |
11 | Electrical life | Not less than 600,000 operations |
12 | Oil compartment of diverter switch | Service pressure | 0.03 MPa |
Leakage test | No leakage under 0.08 MPa for 24 hours |
Over pressure protection | Rupture disc bursts at 300 ± 20% KPa |
Protective relay | Set oil flow speed at 1.0m/s ± 10% |