The 12kV Indoor Earthing Switch 31.5kA (JN15-12/31.5) from Dongfa Intelligent is an indoor earthing switch for switchgear builders, power engineering procurement teams, and buyers seeking factory-direct supply. It is rated for 31.5kA/4s short-time withstand current, 80kA short-circuit making current, 80kA peak withstand current, 42kV power-frequency withstand voltage, and 75kV lightning impulse withstand voltage. Mechanical life is 3,000 operations. It is available in nine phase spacing configurations from 150mm to 275mm. For 150mm phase spacing, phase-to-phase insulating partitions are required. Buyers can request a quote for selection support.
For the 12kV Indoor Earthing Switch 31.5kA, if the line side is energized or backfeed occurs, closing the earthing switch produces a short-circuit current. The 80kA making capability means the switch can withstand the instantaneous peak current without contact welding, fracture, or flying off.
31.5kA RMS is the short-circuit current the earthing switch can withstand continuously for 4 seconds. Combined with 80kA peak withstand current, it covers thermal and dynamic stability requirements.
The series covers phase spacings from 150mm to 275mm. The 150mm configuration requires phase-to-phase insulating partitions.
3,000 operations mechanical life covers typical maintenance switching requirements. At 50 operations per year, it can last 60 years.
The 12kV Indoor Earthing Switch 31.5kA parameters are listed below.
| Parameter | Specification |
| Product Type | Indoor Earthing Switch |
| Product Series | JN15-12/31.5 |
| Rated Voltage | 12kV |
| Rated Short-Time Withstand Current (Thermal Stability) | 31.5kA |
| Rated Short-Circuit Duration | 4s |
| Rated Short-Circuit Making Current | 80kA |
| Rated Peak Withstand Current (Dynamic Stability) | 80kA |
| 1 min Power-Frequency Withstand Voltage | 42kV |
| Rated Lightning Impulse Withstand Voltage | 75kV |
| Mechanical Life | 3,000 operations |
| Phase Spacing Options | 150/165/180/200/210/220/230/250/275mm |
| 150mm Phase Spacing Requirement | Insulating partitions required between phases |
| Model | E | F | G | H | D | C |
| JN15-12/31.5-277 | 188 | 164 | 6.9 | 275 | 55 | 50 |
| JN15-12/31.5-257 | 167 | 359 | 6.9 | 250 | 50 | 50 |
| JN15-12/31.5-237 | 166 | 955 | 6.9 | 230 | 50 | 50 |
| JN15-12/31.5-227 | 166 | 753 | 6 | — | 220 | 50 |
| JN15-12/31.5-217 | 166 | 551 | 6 | — | 210 | 50 |
| JN15-12/31.5-207 | 166 | 349 | 6 | — | 200 | 50 |
| JN15-12/31.5-187 | 165 | 945 | 6 | — | 180 | 50 |
| JN15-12/31.5-167 | 165 | 642 | 6 | — | 165 | 50 |
| JN15-12/31.5-157 | 145 | 139 | 6 | — | 150 | 50 |
The 12kV Indoor Earthing Switch 31.5kA is available in nine standard phase spacing configurations: 150mm, 165mm, 180mm, 200mm, 210mm, 220mm, 230mm, 250mm, and 275mm.
For 150mm phase spacing, the design requires phase-to-phase insulating partitions. Confirm whether the cabinet has space for installing insulating partitions during selection.
When selecting the 12kV Indoor Earthing Switch 31.5kA, confirm the following parameters.
Provide the following for compatibility review:
The technical team reviews replacement project information before production.
Standard products: 7-15 working days. Custom products: 15-30 working days. Standard products support MOQ 1 unit.
Each unit passes resistance test, mechanical operation test, withstand voltage test, and vacuum degree inspection before shipment.
Dongfa Intelligent was founded in 2012 and has 14 years of high-voltage electrical manufacturing experience. Production controls include contact silver plating thickness, transmission mechanism coaxiality, and spring pressure. Certifications: ISO 9001, ISO 14001, ISO 45001. CNAS/IAF recognized testing capability.
The factory is located in Yueqing, China's high-voltage electrical industrial belt. Long-term relationships with local suppliers cover insulators, contacts, springs, and machining. This supports custom phase spacing delivery.
Short-time withstand current (31.5kA/4s) is the RMS short-circuit current the earthing switch can withstand for 4 seconds in the closed state. Short-circuit making current (80kA) is the peak short-circuit current it can withstand at the moment of closing. Making current is typically larger because the closing impact is greatest.
80kA making capability means that if the earthing switch is closed while the line is energized or a short-circuit fault occurs, it can withstand the instantaneous current impact without contact welding, fracture, or flying off.
150mm is a compact phase spacing with small air insulation distance. Insulating partitions increase insulation creepage distance, prevent phase-to-phase short circuits, and ensure insulation reliability in compact cabinets. Confirm cabinet space for insulating partitions during selection.
Select based on switchgear busbar arrangement and phase-to-phase distance. Provide cabinet drawings or original earthing switch mounting dimensions. For replacement projects, confirm original phase spacing and mounting hole distance.
Earthing switches typically operate during maintenance. 3,000 operations covers the equipment lifecycle. At 50 operations per year, it can last 60 years.
Dongfa Intelligent is a 2,000+ m² factory in Yueqing, Zhejiang, founded in 2012, with 14 years of manufacturing experience. Factory audits are supported.
Standard products support MOQ 1 unit. Standard lead time: 7-15 working days. Custom products: 15-30 working days. Urgent orders can be prioritized.
Provide rated voltage, short-time withstand current requirements, short-circuit making requirements, phase spacing, installation dimension requirements, switchgear information, and quantity. Original model and drawings are recommended for replacement projects.
Address
No. 281, Wei 18th Road, Yueqing Economic Development Zone, Yueqing, Wenzhou, Zhejiang, China
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