Ring Main Unit

Compact MV switchgear forming a ring network for reliable, redundant power distribution.

A Ring Main Unit (RMU) is a compact, metal-enclosed switchgear for medium voltage (MV) power distribution, forming a closed loop in the network to ensure reliable, uninterrupted power by allowing electricity to flow from multiple directions, even if one path fails — using switches and circuit breakers to manage load and isolate faults in residential, commercial, and industrial settings. A self-contained unit housing switches, fuses and circuit breakers; load break switches for isolating loads; circuit breakers for protecting and interrupting fault currents; often SF6-gas insulated for compact, safe, maintenance-free operation. Offers enhanced reliability (alternative power paths reduce outage time), fault isolation for safe maintenance without affecting the whole network, and is used indoors or outdoors for buildings, industrial plants and utility networks. Modern versions support remote monitoring.

Available Features

• Application: power distribution
• Construction type: modular indoor metal clad
• Max. rated current: 1250 A, 26.3KA, 1600 A, 40 KA
• Nominal/operational voltage: up to 33 KV
• Rated insulation voltage: 28KV rms/75KVPK
• Ambient temperature: 50 °C
• Type test performed at CPRI: 65.75KA peak & 26.3KA rms for 3 sec; 100 KA peak & 40 KA rms for 3 sec