Active Member
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[China]
Address: No.318 Shengli Road, Xixi Village, Huheng Industrial Zone, Yueqing City, Zhejiang Province.
Contact name:Meng
ZHEJIANG XINKOU POWER EQUIPMENT CO.,LTD |
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| ltem | Unit | Data | |
| Rated voltage | KV | FN12-12D/630 | FN12-12(R)D/125 |
| Rated frequency | HZ | 12 | |
| Rated current | A | 50 | |
| 1min power frequency withstand voltage | KV | 42 to ground and phases fracture 48 | |
| Lightning impulse withstand voltage | KV | 75 to ground and phases fracture 85 | |
| Rated thermal stable current | KA | 630 | 100 |
| Rated dynamic stable current | KA | 50 | |
| Rated switching current(peak) | KA | 50 | 50 |
| Rated short-circuit current(expected) | KV | 31.5 | |
| Maximum breaking current threshold | HZ | Fuse characteratic curve accorting | |
| Minimum breaking current | A | Fuse characteratic curve accorting | |
| Rated transfer current | KV | 50 | 1.5 |
| Maximum breaking current | KV | 1.8 | |
| Breaking OFF-load transformer capacity | KV/A | 1250 | |
| Rated cable charging current | A | 10 | |
| Rated active load current breaking times | Times | 10000 | |
| Opening time when striker strikes | S | <0.06 | |
| Earth switch thermal current switch | KA | 20(2S) | |
| Thermal stable current of earth switch | KA | 50 | 50 |
| Motor operating power supply voltage | V | AC/DC 110/220 | |
| ltem | Unit | Data | |
| FN12-10D/630 | FN12-10(R)D/125 | ||
| The total traveling distance of moving contact | mm | 200+8-2 | |
| Phase center distance (Before energy storage) | mm | 210±15 | |
| Moving contact overtravel distance | mm | 40±2 | |
| Auxiliary contact opening distance | mm | >150 | |
| Opening/Closing time difference among three phase | ms | <3 | |
| Opening speed | m/s | >2.8 | >2.8 |
| Closing speed | m/s | >3.8 | |
| Distance between metal flexible door and torch | mm | >125 | |
| Fracture distance of earth switch | mm | >150 | |
| Main circuit resistance | Ω | <120 | <300 |
| Maximum operating torque | NM | >160 | |
Load Break Switch VS Circuit Breaker
There are two important different parameters as far as the
disconnection/connection of Electrical utilities is concerned.
- Breaking capacity.
- Making Capacity.
Making capacity is more higher since it is considering the initial starting current, inrush and faults that might occur at switching on moment.
Accordingly, the Circuit breakers have both while the Isolator or LBS has only breaking capacity. Isolator therefore used to isolate/disconnect/break load. To be switched on only under no load.
Basically and LBS is only designed to make and break load currents. It can be closed onto a fault (has a making rating) and cannot break a fault current. A CB is designed to make and break fault currents and off course load currents. Need to be careful with switching long cables and long lines with LBS, due to its limitation with switching cable/line charging (highly capacitive) currents. Similar precaution with needed with switching reactive loads like large transformers. Normally a CB is recommended for the 2 latter cases. Check the manufacturer test specs.
In simple way the Load Break Switch used to cut off healthy circuits or to break / disconnect the load. As a precaution, normally the LBS / Isolator are to be switched on under no load, the connected load to be utilized after switching on the Isolator. This why it has no making capacity. Circuit Breakers are intended to operate under unnormal conditions in order to clear the fault & to isolate the defective circuits protecting its associated electrical equipment, therefore breaking and making capacities are considered as the most important criteria as far Circuit breaker are concerned.
The making current is not an RMS value it is the peak value ie. Impk = 2.5Irms. The peak value of 2.5 times RMS is the DC offset at point when the LBS closes on the fault and is taken as the worst case X/R ratio of the source (X/R of about 20). This peak decays to RMS value Ith (thermal withstand current) dependent on the X/R delay constant. The decay rate is exponential with time. There is a misconception that making is 2.5times breaking current, but making is normally quoted as a peak and breaking as RMS. The breaking current in a CB is an RMS value. Breaking fault current is far more difficult that making especially when the contacts open when current is not at zero crossing point on the sine wave. For HV systems 132KV and above, the restrike and TRV starts to become a major consideration in CB selection, especially for long cables and lines.
