Decision facts
Start with system ratings
Verify at least 6 system inputs from the single-line diagram: rated voltage and current, short-circuit withstand, insulation, internal-arc class, protection, and service conditions. A catalog family is not a final project specification.
Evidence
Reviewed: 2026-08-01
Confirm the applicable standard
Use IEC 62271-200 as the reference family, then record 3 controls in the technical agreement: edition, destination rules, and model scope.
Evidence
Reviewed: 2026-08-01
Require model-specific evidence
Before award, request 5 evidence sets: type tests, routine-test plan, drawings, protection schedule, and factory acceptance test scope.
Evidence
Reviewed: 2026-08-01
Make the RFQ decision-ready
A usable RFQ states 8 fields: voltage, current, fault level, feeder arrangement, environment, destination standard, component preference, and delivery boundary.
Evidence
Reviewed: 2026-08-01
Comparison matrix
| Choice | Use when |
|---|---|
| Project-engineered specification | Use for procurement: derive ratings from the single-line diagram, document service conditions, and bind evidence and FAT to the selected model. |
| Catalog-only selection | Do not use for final ordering; a family rating cannot prove project fault duty, protection coordination, environment, or model-specific compliance. |
Technical specification inputs
| Requirement | Project value |
|---|---|
| Start with system ratings | Verify at least 6 system inputs from the single-line diagram: rated voltage and current, short-circuit withstand, insulation, internal-arc class, protection, and service conditions. A catalog family is not a final project specification. |
| Confirm the applicable standard | Use IEC 62271-200 as the reference family, then record 3 controls in the technical agreement: edition, destination rules, and model scope. |
| Require model-specific evidence | Before award, request 5 evidence sets: type tests, routine-test plan, drawings, protection schedule, and factory acceptance test scope. |
| Make the RFQ decision-ready | A usable RFQ states 8 fields: voltage, current, fault level, feeder arrangement, environment, destination standard, component preference, and delivery boundary. |
Decision path
- 1
Start with system ratings
Verify at least 6 system inputs from the single-line diagram: rated voltage and current, short-circuit withstand, insulation, internal-arc class, protection, and service conditions. A catalog family is not a final project specification.
- 2
Confirm the applicable standard
Use IEC 62271-200 as the reference family, then record 3 controls in the technical agreement: edition, destination rules, and model scope.
- 3
Require model-specific evidence
Before award, request 5 evidence sets: type tests, routine-test plan, drawings, protection schedule, and factory acceptance test scope.
- 4
Make the RFQ decision-ready
A usable RFQ states 8 fields: voltage, current, fault level, feeder arrangement, environment, destination standard, component preference, and delivery boundary.
1. Define the ratings
Start with rated voltage (e.g. 12 kV, 24 kV, 40.5 kV), rated current, busbar current and short-time/peak withstand current. These define the basic framework and must come from the single line diagram and load list.
Evidence: Hubei Shiji Senyuan Electric Group, International Electrotechnical Commission
2. Choose insulation and architecture
Decide between air-insulated and gas-insulated (SF6) designs, and between fixed and withdrawable architectures. Gas-insulated and withdrawable options save space or downtime but cost more; match them to site constraints.
Evidence: Hubei Shiji Senyuan Electric Group, International Electrotechnical Commission
3. Specify protection and metering
Define the protection scheme (overcurrent, earth fault, differential where needed), relay type, metering accuracy and communication (modbus / IEC 61850). Clear protection requirements prevent costly field rework.
Evidence: Hubei Shiji Senyuan Electric Group, International Electrotechnical Commission
4. Verify tests and documentation
Request type-test certificates to IEC 62271 / GB 3906, internal arc classification, routine tests and factory acceptance testing records. A manufacturer should supply drawings, bill of materials and coordinated protection settings.
Evidence: Hubei Shiji Senyuan Electric Group, International Electrotechnical Commission
RFQ checklist
- 1.Single-line diagram and load schedule
- 2.Rated voltage, current, and short-circuit level
- 3.Indoor/outdoor environment and IP requirement
- 4.Protection, metering, and communication scope
- 5.Destination standard, FAT, packing, and delivery terms
Frequently Asked Questions
What is the first selection input?
Verify at least 6 system inputs from the single-line diagram: rated voltage and current, short-circuit withstand, insulation, internal-arc class, protection, and service conditions. A catalog family is not a final project specification.
Which standard should the buyer specify?
Use IEC 62271-200 as the reference family, then record 3 controls in the technical agreement: edition, destination rules, and model scope.
Is a catalog rating enough for ordering?
No. Verify at least 6 system inputs from the single-line diagram: rated voltage and current, short-circuit withstand, insulation, internal-arc class, protection, and service conditions. A catalog family is not a final project specification.
What evidence should be requested?
Before award, request 5 evidence sets: type tests, routine-test plan, drawings, protection schedule, and factory acceptance test scope.
What belongs in the RFQ?
A usable RFQ states 8 fields: voltage, current, fault level, feeder arrangement, environment, destination standard, component preference, and delivery boundary.
Evidence sources
- SJSY official product catalogHubei Shiji Senyuan Electric Group
- IEC 62271-200:2021, AC metal-enclosed switchgear above 1 kV and up to 52 kVInternational Electrotechnical Commission
Reviewed by Eshan Peng, General Manager(2026-08-01)
Send drawings for an engineering-grade quotation
Share the single-line diagram, ratings, destination, standards, and delivery boundary for a project-specific review.