Ring Main Unit (RMU) Used in Substation!!

Is an essential component of medium voltage (MV) power distribution networks, primarily used in ring-shaped electrical networks. The RMU

provides a means to protect and control the network, making it crucial for industrial and commercial electrical systems.

Components of Ring Main Unit (RMU):

1. Circuit Breakers: Used to interrupt current flow in case of faults or during system maintenance.

2. Protection Relays: Protect the system from overloading, short circuits, ground faults.

3. Isolators: Used to isolate a part of the network during maintenance.

4. Switches: Allow load transfer between different lines.

5. Metering Units: Monitor voltage, current, and distributed energy.

6. Ring Switches: Used to connect or disconnect any part of the ring to facilitate maintenance / reduce the impact of faults.

Working Principle:

•RMU operates on the principle of ring connection, where power supply points are connected in a closed loop.

• In case of a fault, the affected section can be isolated while maintaining continuous power supply to other sections.

•This design minimizes outages and enhances network reliability.

• This design minimizes outages and enhances network reliability.

Features of RMU:

1. Compact size: ldeal for confined spaces.

2. Operational flexibility: Enables easy maintenance or fault isolation.

3. High reliability: Ensures continuous power service.

4. Safety: Provides high protection against electrical faults.

Applications:

•Urban power distribution networks.

• Industrial plants and facilities.

• Shopping mall and commercial buildings.

• Substations.