Maintenance-Free Design Indoor Gas-Insulated SF6 Circuit Breakers
Key attributes
| Brand | ROCKWILL |
| Model NO. | Maintenance-Free Design Indoor Gas-Insulated SF6 Circuit Breakers |
| Rated voltage | 12kV |
| Rated frequency | 50/60Hz |
| Series | JGHD4 |
Product descriptions from the supplier
Description
1.Product Overview
The JGHD4 medium voltage circuit breaker uses sulfur hexafluoride(SF6) gas as an arc extinguishing and insulating medium. SF6 gas has a smooth breaking characteristic, in which no current cut-off phenomenon occurs when breaking the current, and no operating over voltage is generated. This excellent characteristic ensures that the circuit breaker has a long electrical life. And the impact, dielectric level and thermal stress on the equipment during operation will not be affected. The pole of the circuit breaker, that is, the arc extinguishing chamber part, is a closed system that is maintenance-free for life. Its sealing life meets the IEC 62271-100 and CEI 17-1 1375 standards. The opening/closing process of the JGHD4 circuit breaker is completed by the REH type spring operating mechanism.
The operating mechanism and the pole are fixed on the same metal frame. It also serves as a trolley, which can be pushed in and out along the guide rail in the switchgear. The trolley movement can be operated when the cabinet door is closed.
The lightweight and compact circuit breaker structure ensures its sturdiness and reliability.
The JG series automatic reclosing device integrates control, protection, measurement, communication, fault detection, and online monitoring of closing and opening.
2. Features
- Automatic buffer technology
- Arc extinguishing without chopping
- No reignition after disconnection
- Extinguishing method for rapid recovery of dielectric properties
- Withstands insulation voltage even at zero relative pressure (*)
- Up to 30% of rated breaking capacity even at zero relative pressure (*)
- Lifetime sealed poles
- Three gas tightness check tests for each device
- Compact dimensions
- Fixed and withdrawable
- Energy storage operating mechanism with anti-tripping device as standard
- Entire circuit breaker range
- Mechanical safety lock to prevent incorrect operation
- Simple personalization thanks to a complete range of accessories
- Maintenance-free
- SF6 gas pressure control device (on request)
3. Applications
JGHD4 circuit breakers can be used for the control and protection of distribution lines, substations, distribution stations, motors, transformers and capacitor banks.
Due to the use of SF6 automatic buffer breaking technology, JGHD4 circuit breakers will not generate operating over voltage, so they are very suitable for use in places that are particularly sensitive to the dielectric strength level of insulating materials, especially for capacitor banks, compensating reactors, motors and other capacitive and inductive load applications.
4. Arc extinguishing technology
The arc extinguishing principle of JGHD4 circuit breaker is based on thermal expansion (self-energy type) + compressed air blowing. Regardless of the current value, it can ensure that the arc is gradually extinguished, and the arcing time is short, without current cutoff and reignition.
JGHD4 series products use the thermal expansion + compressed air blowing arc extinguishing technology that has been maturely used in the field of high-voltage switches, giving it an advantage in medium-voltage switches.
5. Main technical data
| SF6 Circuit Breaker | JGHD4-12 | JGHD4-17 | JGHD4-24 | JGHD4-36 | JGHD4-40 | |
| Standard | IEC 62271-100, CEI 17-1, 1375 | |||||
| Rated voltage | (Ur) [kV] | 12 | 17.5 | 24 | 36 | 40.5 |
| Rated insulation voltage | (Us) [kV] | 12 | 17.5 | 24 | 36 | 40.5 |
| 50 Hz (1 min) power frequency withstand voltage | (Ud) [kV] | 28 | 38 | 50 | 70 | 85 |
| Pulse withstand voltage | (Up) [kV] | 75 | 95 | 125 | 170 | 185 |
| Rated frequency | (Fr) [Hz] | 50/60 | 50/60 | 50/60 | 50/60 | 50/60 |
| Rated operating current | (Ir) [A] (40°C) | 830/800 | 1250/1800 | 2000/2500 | 3150/3800 | — |
| Rated breaking capacity | (Isc) [kA] | 12.5/10 | 25/31.5 | 50/50 | 50/50 | 50/50 |
| Rated short-time withstand current | (Ik) [kA] | 12.5/10 | 25/31.5 | 50/50 | 50/50 | 50/50 |
| Rated short-circuit closing current | (Ip) [kA] | 31.5/40 | 50/63 | 80/100 | 100/125 | 100/125 |
| Rated operating sequence | O-0.3s-CO-15s-CO | |||||
| Breaking time | [ms] | 45 | 45 | 45 | 45 | 45 |
| Arc burning time | [ms] | 10–15 | 10–15 | 10–15 | 10–15 | 10–15 |
| Opening time | [ms] | 55–60 | 55–60 | 55–60 | 55–60 | 55–60 |
| Closing time | [ms] | 80 | 80 | 80 | 80 | 80 |
| Maximum overall dimensions | H [mm] | 540 | 549 | 818 | 730/1060 | 790/1123 |
| W [mm] | 493 | 518 | 730 | 880/955 | 748/80 | |
| D [mm] | 498 | 498 | 820 | 695 | 833 | |
| I [mm] | 150 | 210 | 275 | 350 | 275 | |
| Pole center distance | [mm] | 150 | 210 | 275 | 350 | 275 |
| Weight | [kg] | 114 | 114 | 119 | 128 | 190 |
| SF6 gas absolute pressure | [kPa] | 380 | 380 | 380 | 380 | 450 |
| Operating environment temperature | [°C] | -5 to +40 | ||||
| Humid tropical type electrical appliances | IEC: 60068-2-30, 60721-2-1 |
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| Electromagnetic compatibility | IEC: 60694 | |||||
