Tag Archives: RING MAIN UNIT

Ring Main Unit

The Ring Main Units(RMU) are designed to use the secondary distribution of 15/24/33 kV class underground line and to enable connection, supply and protection by current limiting fuse combination. It can be use to protection one or two transformers in combination with circuit breaker, RMU has been designed for use as a stand alone device or can be easily integrated into distribution automation and remote control schemes using the inbuilt communications capability.

The in-built user configurable distribution automation functionality can be used with or without a communications system and will reduce outage time and increase profitability in your network. RMU can offer with motorized mechanism ,controller, RTU & remote operation.


– Reliable ON-OFF-Earthed three-position switch and Toggle-spring operation mechanism

– Maintenance free and easy installation

– Bushing standardized for ANSI standard at front panel for cable connection with elbow connector.

– Compact Switchgear Solution for Secondary Distribution

– Compact and light weight design

– Modular design using Spring Charging Mechanism

– Mechanical operating Stability

– All functions necessary for such applications – sensing, control and communications


– Metal enclosed tank is hermetically sealed, this has no influence with environmental effect between inner and outer tank effects such as dirt, small insects, and moisture and so on.

– Load break switch operating is possible in the front of Ring Main Units.

– All switching operations can be made safely to personnel because of interlocking system that operates manually according to the switch position by the operator.

– CB will be tripped when Fault current occurs automatically.


– Metal enclosed unit for indoor installation and type tested.

– Insulated by SF6 Gas

– No Influence with climate.

– ON-OFF-EARTH, three position load break switch.


– Approachable and operable safely in the presence of power in the cables.

– Clear indication of operation status via mimic diagram on front panel.

– Automatic interlocking system between CB & DS.

– Voltage detector to check the presence of voltage in the cable.

– Clear indication of operation status and pressure gauge

Contact us for inquiry, get catalogues and more technical information.