QCG-12 Solid-Insulated Ring Main Unit
The QCG series is a compact, SF6-free solid-insulated ring main unit for 12/24 kV secondary distribution systems. Primary live parts are sealed in solid insulating material, while feeder functions, protection, metering and automation are configured from the approved single-line diagram.
Product Scope
- Series: QCG (STQCG)-12
- Insulation route: solid insulation, SF6-free
- Functional units: C load-switch unit, F switch-fuse unit and V vacuum circuit-breaker unit
- Supply form: individual functional units or project-configured line-ups
Typical Technical Data
| Rated voltage | 12/24 kV |
|---|---|
| Rated frequency | 50/60 Hz |
| Rated current | 630/1250 A |
| Rated short-time withstand current | 20/25 kA (4 s) |
| Rated peak withstand current | 50/63 kA |
| Power-frequency withstand voltage | 42 kV / 1 min |
| Lightning impulse withstand voltage | 75 kV |
Values are standard project-selection references. Final ratings, test scope and applicable standard are confirmed in the approved technical agreement.
Functional Units
| Unit | Typical function |
|---|---|
| C unit | Incoming, outgoing or ring-main load switching. |
| F unit | Switch-fuse combination for transformer protection. |
| V unit | Vacuum circuit-breaker feeder for protection and control. |
Applications
- Urban and industrial distribution networks
- Factories, commercial facilities and infrastructure
- Compact substations and indoor distribution rooms
- Solar, wind and distributed-energy projects
Project Configuration
Unit arrangement, protection scheme, cable interface, operating mechanism, auxiliary voltage, enclosure requirements and applicable standards are matched to the project SLD and specification.
Information Required for Quotation
- Single-line diagram and unit combination
- Rated current and short-circuit level
- Protection, metering and automation requirements
- Cable size, termination and interface requirements
- Installation environment and applicable standard
Ready for configuration review? Submit the SLD, ratings, quantity and destination through the Request a Quote page.
Arrangement reference drawing
FAQ
What is a solid-insulated RMU?
It uses solid insulation around the main circuit and is intended for compact medium-voltage distribution applications.
Where is it used?
Typical applications include utility distribution, industrial plants, infrastructure, renewable-energy projects and compact substations.
Which functional units are available?
Cable switch, circuit-breaker, metering, PT and project-specific combinations can be arranged according to the SLD.
What rated current is available?
Typical 630A and 1250A configurations can be evaluated; final ratings follow the controlled product schedule.
How is the short-circuit rating selected?
It must match the project fault-level study, protection philosophy and applicable technical specification.
Are dimensions fixed?
No. Dimensions depend on functional units, interfaces and the final lineup. The approved GA drawing controls production.
What information is needed for quotation?
Send voltage, current, fault level, SLD, quantity, cable and protection requirements.
Can engineering and FAT support be provided?
Yes. Technical clarification, GA drawings, routine tests and agreed FAT support are available for confirmed projects.
Send Your SLD or Specification
Receive project-specific configuration, technical clarification and quotation support.
Verified model evidence
QCG-12 Model-Specific Test Report
- AY0502452-2020 — QCG (STQCG)-12 C/F/V units
The listed report applies only to the stated model and scope. Full interiors remain controlled.