SF6 Gas Insulated Ring Main Unit, AQGN series

Gas insulated ring main unit (AQGN RMU) not only suitable for network nodes and terminal connection, but also satisfy the requirements of the flexible use of compact switchgear in various secondary substations.

AQGN RMU is a fully enclosed switching system, all the electrical parts and switching units are contained in a stainless steel tank, ensuring a constant working condition without affecting from external environment while providing a high level of reliability and personnel safety, as well as maintenance-free operation. With the use of external busbar, the switching system can be fully modular, achieving flexible combination. The external busbar is fully insulated and shielded to ensure high reliability and safety. AQGN RMU is available in 2, 3, 4, 5 or 6 way unit, and can be supplied with additional equipment according to customers’ requirements.

AQGN series ring main unit is certified in accordance with IEC62271-200 standard, operating lifetime is over 30 years under indoor conditions (20°C)

Applications Compact secondary substation
Small-size plant
Wind power station
Hotels, shopping centers, office buildings, commercial centers, etc.
Rail and transit
Features
Unification of fixed and flexible expansion

AQGN is the ring main unit structure, and able to contain 6 modules in one SF6 insulated air tank. It provides 16 combinations to meet various applications. The combination types include CF, CCC, CCF, CCCC, CCCF, CCVV, CCCCC, CCFFF, CCCFF, CCCCF, CCCCCC etc.

Compact structure

All modules have the width of 325mm only except metering cubicle and circuit breaker module. The width of the metering cubicle is 696mm. The circuit breaker module is available in three options in width, i.e. 446/500/696 mm.

No affecting from environment

All the electrical parts are contained in a stainless steel tank which is sealed by welding process. The SF6 gas pressure is 1.4bar or 1.24 bar, and the protection class of tank is IP67. AQGN series switching system is applicable to substations in damp, sandy, dusty, salty areas, and no need to take special preventing measures. The fuse cabinet is also IP67 rated, and external busbar is fully insulated and shielded, ensuring that the system will not be affected by environment conditions and a maintenance free operation.

High reliability for personal safety

All the electrical parts are sealed in SF6 gas tank. The switch has reliable pressure relief channel and has passed 20kA/1s internal arcing test, the load and earthing switch is a three position switch so that the interlocking is simplified. The cover of the cable compartment and the load switch have reliable mechanical interlocking.

Environmental Conditions

AQGN are operated in general indoor conditions according to IEC62271-1/GB/T 11022-2011

Ambient temperature
Max. temperature: 40˚C
Max. temperature: 35°C (average in 24h)
Min. temperature: -40°C Humidity
Max. average relative humidity
Measured in 24h: ≤95%
Measured in one month: ≤90% Altitude: ≤1000m (under standard gas pressure) SF6 gas pressure: 1.24 bar (12 kV) / 1.4bar (24 kV) at 20˚C Leakage rate: 0.25‰/year Submersion test: applying pressure 0.3bar under water for 24h, 24kV Arcing test: 20kA 1s Technical Parameters

Item		Unit	C-module	F-module	V-module
Rated voltage		kV	12/24
Rated frequency		H z	50
Rated current		A	630	125	630
Rated short time withstand current		kA	25	/	25
Rated short-circuit making current		kA	63	/	63
Rated peak withstand current			63	/	63
Rated load break switch current		A	630	/	630
Rated short-circuit breaking current		kA	/	31.5	25
Rated insulation	Power frequency withstand voltage (1 min)	kV	42/65
	Lightning impulse withstand voltage(peak）		75/125
Degree of protection			IP4X(enclosure)/IP67(gas tank)
Mechanical endurance		times	5000	5000	10000