Solid Insulated Ring Main Unit | Ring Breaker

Products
Ring Main Unit (RMU)
Smart Solid Insulated RMU

RING MAIN UNIT

Smart Solid Insulated RMU

The HSIS-12 solid insulated ring main unit was developed by HCRT according to market demands which indicated that three-phase 50Hz systems with rated voltage of 12kV were common. This unit has the following advantages: modular, high electrical performance, high environmental protection, and easy installation. By being equipped with intelligent controllers such as an DTU and other related equipment, this ring main unit can realize different levels of control, measurement and protection functions, in order to meet the various requirements of our customers.

Application

The inside of this solid insulated ring main unit adopts a rotary fuse structure, which makes the replacement of the fuse cubicle type and making it extremely easy. The size of this unit is the smallest of all gas insulation cabinets, covering the least area, and it is eco-friendly for the power supply and distribution of urban users and residential applications.

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Technical Specifications

	Load Break Switch (Cabinet C)	Circuit Breaker (Cabinet V)	Switch-Fuse Combination (F)	Disconnector/Earthing Switch
Rated voltage (kV)	12	12	12	12
Rated current (A)	630	1250	125	630
Rated frequency (Hz)	50	50	50	50
Arc extinction	Vacuum	Vacuum	Vacuum
Power-frequency withstand voltage (kV)	42	42	42	42
Lightning impulse withstand voltage (kV)	75	75	75	75
Rated short-circuit breaking current (kA)		20/31.5
Breaking times of rated short-circuit breaking current		30
Rated short-circuit closing current (kA)	50	50/80		50/31.5
Rated short-time withstand current (kA)	20/31.5	20/31.5		20/31.5
Rated short-circuit duration (s)	4	4		4
Rated peak withstand current (kA)	50/80	50/80		50/80
Rated cable-charging breaking current (A)	10
Rated take over current (A)			1750
Arc duration (s)	1	1	1
Partial discharge (pC)	≤5	≤5	≤5
Mechanical life (times)	10,000	10,000 (spring) 30,000 (permanent magnet)	10,000	3,000
IP class	IP67

Features

Full insulation and full enclosure.

Modular

The ring main unit has flexible wiring schemes.

It uses environmental friendly materials

The unit adopts automatic control.

It has clear operation interface: the operating sequence is linked with switch interlocks.

The solid insulation outer surface covers the ground plane.

The unit has excellent weather resistance

The ring main unit has small size and compact structure.

Operating Conditions

Maximum Ambient Temperature: +60℃

Minimum Ambient Temperature: -40℃

Relative Humidity: Daily average ≤95%, monthly average ≤90%

Seismic Grade: 8

Operating Altitude: ≤4000 meters above sea level

Note: Contact HCRT if a different condition is required. We offer customized solutions as well.