Recently, Huaming launched its on-tank reactive vacuum OLTC HWDK. It's a 3-phase on-load tap-changer, composed of one diverter switch and one tap selector, designed for large-current on-load voltage regulation in utilities and industries.
The current path during the switching sequence is shown in red.
Note: VS: Vacuum interrupter; P1, P4: Tap selector contact; P2, P3: Main contact
The technical data is as below
Type | HWDK |
Max. rated through-current Ium (A) | 1500 | 2000 |
Rated frequency (Hz) | 50 60 |
Max. rated voltage tap-to-tap (V) | 2000 |
Max. rated voltage per step (V) | 1000 |
Rated step capacity (kVA) | 3000 | 4000 |
Standard operating positions (with change-over selector) | 33 | 33 |
Regulating winding section | 9（8 effective） |
Short-circuit current test (kA) | Thermal (3s) | 12 |
Dynamic (Peak) | 30 |
Insulation to ground（KV） | max. continuous voltage between circuits（IEEE/CSA）（KV） | 72.5 |
Rated separate source AC withstand voltage (50Hz 1min) | 140 |
Rated lightning impulse withstand voltage（1.2/50us） | 400 |
Maximum and minimum insulation level of switch (limit range) (kV) | Rated separate source AC withstand voltage (50Hz 1min) | 70 |
Rated lightning impulse withstand voltage（1.2/50us） | 250 |
Insulation level between two taps stages (KV) | Rated separate source AC withstand voltage (50Hz 1min) | 50 |
Rated lightning impulse withstand voltage（1.2/50us） | 125 |
Mechanical life | 1,500,000 operations |
Vacuum contact life | 600,000 operations |
Maintenance interval | 500,000 operations |
Tap changer oil tank | Leakage test | No leakage under 0.08 MPa for 24 hrs |
Withstand full vacuum （±17psi） |
Dimension of tap changer oil tank (in) | L×W×H | 68×33×46 |
Weight (lb.) | 3009 |
Filling volume of oil tank (us gal) | 383 |