RMU Switchgear Selection Guide for Medium-Voltage Ring Networks

RMU Selection

Published 2026-05-09 | Updated 2026-05-09

RMU switchgear selection for medium-voltage ring networks

Short Answer

Specify RMU switchgear by voltage class, feeder quantity, load switch or circuit breaker function, rated current, short-circuit rating, cable direction, protection, enclosure, and required drawings or certificates.

Confirm the Ring-Network Scheme

An RMU is usually selected for compact medium-voltage distribution where feeders need switching, isolation, and protection in a small footprint. It is common in compact substations, urban distribution, commercial buildings, and infrastructure projects.

The buyer should provide the feeder scheme before asking for price. A two-way, three-way, or multi-feeder RMU can vary significantly in load switch, fuse combination, breaker, metering, and protection configuration.

  • Voltage class: commonly 12kV, 24kV, or 40.5kV depending on project.
  • Feeder function: incoming, outgoing, transformer protection, or ring feeder.
  • Operation: manual or motorized mechanism if required.
  • Documents: drawing, single-line diagram, component list, and test reference.

Do Not Compare RMU Quotes by Cabinet Name Only

A low RMU price may exclude required protection, motor operation, metering, cable accessories, enclosure details, or documentation. Buyers should make each supplier quote the same feeder scheme and technical requirements.

Rated current, short-circuit level, insulation arrangement, interlocking, cable entry, and installation environment all affect final cabinet design and cost.

Connect RMU Selection to the Whole Project

RMUs are often purchased together with compact substations, transformers, and low-voltage cabinets. The buyer should check how the RMU interfaces with transformer protection, cable routes, grounding, and local operation requirements.

Jinxing Electric can support RMU quotation together with transformer and substation equipment when the buyer provides a single-line diagram and project site requirements.

FAQ

1. What is the difference between RMU and MV switchgear?

An RMU is a compact type of medium-voltage switchgear commonly used for ring-network distribution, while larger MV switchgear lineups can support more complete feeder and protection configurations.

2. Can RMU switchgear be quoted with a compact substation?

Yes. RMU, transformer, LV cabinet, enclosure, drawings, and documentation can be reviewed together for compact substation projects.