The CKAI-12 Series Normal-Pressure Sealed Air-Insulated Ring Main Unit (RMU) uses dry air as the insulating medium and a micro-pressure vacuum interrupter for arc extinction. Its key switching components are fully enclosed in a dry-air-filled stainless steel gas tank, providing excellent insulation, sealing performance, and IP65-rated protection.

Eco-feiendly and safe: The product uses air as the insulating medium and vacuum arc extinction technology, without the use of SF₆ gas. More than 95% of its materials are eco-friendly and recyclable, helping minimize environmental impact.

Compact structure: With a compact, modular and maintenance-free design, the circuit breaker, load switch, disconnector, sealed tank, operating mechanism and cabinet are designed as independent modules. These modules form standardized functional units, making factory prefabrication and assembly easier and more efficient.

Easy expansion: The product supports flexible expansion and can be equipped with either spring or permanent-magnet operating mechanisms. It adopts a lower disconnector and lower earthing switch structure, with overall dimensions of 500 mm W × 920 mm D × 2000 mm H. Side expansion and common-tank configurations make installation and future expansion more convenient.

Safe and reliable: All primary high-voltage components are fully enclosed in a stainless steel sealed tank with an IP65 protection rating, enabling an overall maintenance-free design. The sealed tank balances internal and external air pressure through an air-filtering device, keeping the internal pressure consistent with the ambient atmospheric pressure.

Excellent performance: Through electric field simulation, calculation and optimization, the product achieves excellent electrical performance, a uniform electric field distribution, and effectively avoids partial discharge risks and hidden hazards.

High intelligence: Through electric field simulation, calculation and optimization, the product achieves excellent electrical performance, a uniform electric field distribution, and effectively avoids partial discharge risks and hidden hazards.

Serial Number	Name			Unit	Parameter
					CKAI-12/C	CKAI-12/V
1	Rated voltage			kV	12
2	Rated frequency			Hz	50
3	Rated current			A	630
4	Rated insulation level	1min power frequency withstand voltage	Ground and interphase	kV	42
			fracture	kV	48
		Rated lightning impulse withstand voltage	Ground and interphase	kV	75
			fracture	kV	85
5	Rated closed-loop interrupting current			A	630	/
6	Rated cable charging breaking current			A	10	25
7	Rated short-circuit breaking current			kA	/	25
8	Rated short-term withstand current			kA	20	25
9	Rated peak withstand current			kA	50	63
10	Rated short-circuit closing current (peak value)			kA	50	63
11	Mechanical life			time	10000	20000
12	Mechanical life of disconnector and earthing switch			time	3000
13	loop resistance			μΩ	≤150
14	Gas rated pressure (20℃ gauge pressure)			Mpa	0
15	Protection grade of closed inner shell			/	IP65
16	Enclosure protection grade			/	IP4X