SF6 Ring Main Units (RMU) | Medium-Voltage Switchgear

Products
Ring Main Unit (RMU)
Smart SF6 Gas Insulated RMU

Medium-Voltage Switchgear

SF6 Gas Insulated Smart RMUSmart Ring Main Unit

Standards: IEC 62271-200:2011, IEC 62271-100:2008, IEC 62271-103:2011, IEC 62271-1:2007, IEC 62271-102:2018

The SF6 Gas Insulated Smart RMU completely seals all live components within the SF6 gas tank, achieving an IP67 protection level. This design ensures the entire medium-voltage switchgear is unaffected by the external environment, guaranteeing safe and reliable operation.

Primarily used as a ring main unit in power distribution networks or for power distribution to end-users, it is commonly found in prefabricated box-type substations, and switching stations.

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Technical Specifications

Component	Load Break Switch (Cabinet C)		Circuit Breaker (Cabinet V)		Switch-Fuse Combination (F)		Disconnector/Earthing Switch
Rated voltage (kV)	12	24	12	24	12	24	12	24
Rated current (A)	630		630		125		630
Arc extinction	SF₆ gas		Vacuum		SF₆ gas		SF₆ gas
Power-frequency withstand voltage (kV)	42	65	42	65	42	65	42	65
Lightning impulse withstand voltage (kV)	75	125	75	125	75	125	75	125
Rated short-circuit breaking current (kA)			20/25
Rated peak withstand current (kA)	50/63		50/63				50/63
Arc duration (s)	1		1		1
Mechanical life (times)	5,000		10,000 (spring) 30,000 (permanent magnet)		5,000		3,000
Filled pressure (SF6 gas)	0.04 Mpa (≈0.4 bar)
Annual leakage rate (SF6)	≤0.01 %
Internal arc classification	A (FLR)
IP class (gas tank/indoor/outdoor)	IP67/IP41/IP54

Features

Enhanced Safety:

Three-position load switch interlock with clear position indication and power distribution status display ensures operational safety.

Robust Arc Fault Protection:

Equipped with reliable pressure relief channels and an anti-arc fault design, successfully passing the internal arc type test.

Smart Grid Ready:

Optional integration of intelligent devices such as Distribution Terminal Units (DTUs) enables advanced smart grid functionalities.

Versatile Configuration:

Offers a range of configuration options including top and side cable outlets, high-voltage emergency power supply interfaces, secondary interface modules, and aviation plug connectors.

Customized Solutions:

Tailored design solutions are available to meet specific customer requirements and project needs.

Operating Conditions

Maximum Ambient Temperature: +60℃

Minimum Ambient Temperature: -40℃

Relative Humidity: daily average ≤95%, monthly average ≤90%

Seismic Grade: 8

Operating Altitude: ≤2000 meters above sea level

Note: Contact HCRT if a different condition is required. We offer customized solutions as well.