Product Description
| 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 |
12kv load break switch air load break switch outdoor hv break
switch
| 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 |
12kv load break switch air load break switch outdoor hv break
switch
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.
