Ring Main Unit

HXGN-12 Indoor Fixed Ring Main Unit

HXGN-12 is an indoor, fixed metal-enclosed ring main unit for receiving and distributing power in 12 kV secondary networks. It brings switching, isolation and circuit protection together for cable ring networks, terminal distribution points and compact substations.

The 630 A series uses load-switch or switch-fuse units. The load-switch main circuit has a short-time withstand rating of 20 kA for 4 seconds. Unit combinations are selected for the feeder arrangement and transformer protection scheme, with cable termination space and operating access matched to the switchroom.

Technical Specifications

Rated Voltage	12 kV
Rated Frequency	50 Hz
Rated Current	630 A
Short-Time Withstand Current	20 kA (4 s, load-switch main circuit)
Peak Withstand Current	50 kA (load-switch main circuit)
Power-Frequency Withstand Voltage	42 kV / 1 min
Lightning Impulse Withstand Voltage	75 kV
Switching Units	Load switch / switch-fuse
Enclosure IP Rating	IP2X
Standards	GB 3906 / IEC 298

Key Features

Compact fixed ring-network design.
For 12 kV secondary distribution.
Load-switch and switch-fuse configurations.
Metal-enclosed construction with IP2X protection.

Typical Applications

Industrial distribution rooms
Commercial building substations
Compact transformer substations

Installation & Aftercare

Prepare the site, plan routine checks and keep service records.

What needs to be ready before installation?

Use an indoor switchroom with a stable foundation, operating clearance and room for cable bends and fuse access.
Match the supplied load-switch or switch-fuse configuration to the branch duty and cable connections before commissioning.
Keep insulation and mechanisms free from condensation and conductive contamination; provide earthing and any specified moisture-control equipment.

What should operators check during routine rounds?

Check position indications, unusual noise and room moisture during rounds; keep the circuit diagram and cable labels readable.

What is covered during planned maintenance?

At planned isolation, qualified personnel inspect interlocks, earthing and operating mechanisms, fuse holders and cable terminations.
Investigate fuse operation before replacement, and use the approved fuse type; shorten inspection intervals where dust or condensation accumulates.

Customization Options

Define the electrical configuration and the details needed for your site.

Network arrangement: Incoming ring circuits, transformer feeders, terminal supplies and future extension requirements.
Switching units: Load-switch or switch-fuse arrangement; select the fuse combination for the transformer rating and network fault duty.
Protection & metering: Fuse or relay protection arrangement, CT ratios, metering and fault-indication requirements.
Cable interfaces: Cable count, cross-section, termination type and earthing connections.
Controls & enclosure: Operating mechanism, auxiliary supply and remote signalling; enclosure and site conditions for engineering review.

Project-specific options and accessories are confirmed in the quotation and approved drawings.