Air-Insulated Ring Main Unit

General Description:

  1. The Air-insulated Ring Main Unit is a factory built, metal-encapsulated switchgear, prewired and tested, eliminating technical coordination problems and ensuring short delivery time and simple erection.
  2. Local work is limited to the connection of external power cables.
  3. The Ring Main Unit is designed for either indoor or outdoor installation.
  4. The Ring Main Unit is mainly used in secondary distribution.
  5. It integrates from 1 to 4 load-break switches for cable or transformer, an earth fault indicator and an arc extinguishing device.
  6. The Ring Main Unit also has the option for installing Metering devices.

Main Features:

– High operating reliability
– Simple maintenance and inspection
– No isolating partitions
– High dynamic and thermal strength
– Encapsulated extinguishing device
– Current interruption without visible arc
– High number of operation, simple mechanism
– Easy cable connection
– Possible to be connected with any SCADA system

12 & 24 KV Ring Main Units passed all necessary tests carried out in The Egyptian Electricity
Authority Pyramids High Voltage Research Center and approved from The Egyptian Electricity
Holding Company.

The Ring Main Unit is designed, manufactured and tested in conformity to the latest standards
– IEC 60271-200
– IEC 60694
– IEC 60271-102
– IEC 62271-105
– DIN VDE 0670

Compact Design

Modular Design

Rated Voltage 12 KV17.5 KV24 KV
Rated Frequency50/60 HZ50/60 HZ50/60 HZ
Rated Current
Ring Switch 630 A630 A630 A
Transformer Switch 630 A630 A630 A
Busbars630 A630 A630 A
Power Frequency Test Voltage28 KV38 KV50 KV
Impulse Withstand Test Voltage75 KV95 KV125 KV