20kv Gas Insulated Ring Main Unit (SF6)

20kv Gas Insulated Ring Main Unit (SF6) Introduction

- Fill the gas box with SF6 vapor and undergo synchronous vacuum packaging for leak detection; The high-voltage load switch, grounding device power switch, circuit breaker insulation layer cylinder and other power switch themed movable components, as well as the bus duct, are sealed in a stainless steel plate air box. The waterproof level of the air hood is P67, and the dust collector is equipped with a glass diaphragm. When the internal pressure of the power switch exceeds a certain working pressure, it can be discharged from the explosion-proof port below, which can reasonably avoid harm to people, cables, and other switchgear in the distribution station.

1. What is the primary function of a 20kV Gas Insulated Ring Main Unit (RMU)?
   It is designed for power distribution in medium-voltage networks, providing reliable switching, protection, and isolation in a compact SF6-insulated enclosure.

2. What are the key advantages of SF6 gas insulation in RMUs?
   SF6 gas offers excellent dielectric strength, arc-quenching properties, and compact design, reducing footprint and maintenance needs compared to air-insulated units.

3. What is the rated current and short-circuit withstand capacity of this RMU?
   Typical ratings include 630A normal current and 20kA/3s short-circuit withstand capacity (specific values depend on the model).

4. Is the RMU suitable for indoor and outdoor installation?
   Yes, it is designed for both indoor and outdoor use, with IP67 protection for dust and water resistance.

5. How is the SF6 gas leakage monitored in the RMU?
   Modern units feature integrated gas density monitors with alarms to detect low-pressure conditions, ensuring safety and performance.

6. What switching functions does the RMU support?
   It includes load-breaking, fault-making, and isolating functions, with optional motorized operation for remote control.

7. Can the RMU be integrated with smart grid systems?
   Yes, it supports SCADA communication via protocols like IEC 61850 or Modbus for real-time monitoring and automation.

8. What maintenance is required for an SF6-insulated RMU?
   Minimal maintenance is needed due to sealed construction, but periodic checks of gas pressure, mechanical linkages, and contacts are recommended.

9. How does the RMU ensure operator safety during switching?
   It features interlocking mechanisms, insulated operating tools, and visible earth switches to prevent accidental contact with live parts.

10. What environmental regulations apply to SF6 gas in this RMU?
    The unit complies with IEC 62271-200 standards, and SF6 handling follows F-gas regulations to minimize emissions (recycling/recovery procedures are mandatory).