Two vacuum circuit-breaker quotations can show the same voltage and current ratings yet cover very different purchases. One price may include the controller, current transformers and mounting parts. Another may cover the breaker alone. Lead times can also start at different points: receipt of an order, payment or approval of drawings. Unless those differences are clear, comparing the totals tells the buyer little. A useful request for quotation describes the equipment’s job, how it will be installed and what the supplier must deliver with it. That gives suppliers enough information to price the same requirement.
A vacuum circuit breaker RFQ should include the electrical duty, mechanical installation, controls, service conditions and required documents. Add quantities, delivery terms, acceptance tests, spares and warranty questions. IEC 62271-100 provides the AC circuit-breaker performance requirements within its scope, but the project’s ratings and application still need to be stated. For a retrofit, provide information about the existing switchgear as well. The supplier can then return an offer that identifies the model, included equipment, exceptions and delivery milestones, rather than leaving those items to be settled after the order.
What information does the supplier need to select the breaker?
Send the single-line diagram and a rating schedule. It should state maximum system voltage, frequency, insulation levels, normal current, short-circuit breaking and making duties, short-time withstand and operating sequence. Identify the circuit being switched. A transformer feeder, capacitor bank and generator connection should not be described simply as “medium voltage”.
Include the installation conditions: indoor or outdoor service, altitude, ambient temperature, humidity and pollution. These details allow the supplier to assess the offered design and identify restrictions before pricing is finalised.
Application matters because breakers are offered for different duties. ABB’s primary breaker portfolio, for example, separates generator, capacitor and arc-furnace applications. Describe the actual load and operating requirements so the quotation addresses them.
Which electrical and mechanical data belong in the RFQ?
For a new panel, provide the arrangement and interfaces the breaker must suit. For a replacement, include the existing breaker identity, available drawings and installation measurements. Mounting dimensions alone leave out primary contacts, earthing, interlocks and secondary connections.
Control requirements need the same attention as primary ratings. State the trip and close supply voltages, auxiliary contacts, interlocks and local/remote functions. Identify any reclosing or communications requirement. The guide to retrofit mounting and control connections explains the information needed when an existing panel is being retained.
| Send with the enquiry | Ask the supplier to include in the offer |
|---|---|
| Electrical rating schedule and circuit application | The offered ratings and any differences |
| Arrangement drawings and installation details | A general arrangement drawing and interface information |
| Control supply and required functions | A control schematic, terminal list and controller description |
| Service conditions | Applicable operating limits |
| Required standards and documents | Relevant test-report references and the delivery document list |
How should buyers compare delivery scope and lead time?
Break a VCB project quotation into its supplied items before comparing price. Identify the breaker, mechanism, controller, instrument transformers, connectors, mounting parts and spares. Mark which items are included, optional or supplied by the buyer. If installation or commissioning support is needed, give it a separate line.
For lead time, ask two questions: when does the clock start, and what is ready at the end? “Ready for dispatch after drawing approval” differs from delivery to the site after the purchase order. Payment, technical approval, witness testing and export documents may affect the schedule. Get the milestones for the exact quantity and configuration in writing.
| Item to compare | Question that makes the offer clearer |
|---|---|
| Delivery time | Does it begin at order, payment or drawing approval, and does it end at dispatch or arrival? |
| Transport and delivery terms | Which Incoterms rule, edition and named place apply? |
| Testing and documents | Are witness tests, records and required translations included? |
| Spare parts and services | What is included now, and what support can be ordered later? |
| Warranty | When does coverage begin, what does it cover and how is a claim resolved? |
An online listing does not establish current stock. Ask whether the precise model and accessories are available, whether the required documents are ready and whether stock can be reserved against the order.
Which tests and documents should be agreed before ordering?
Type-test evidence concerns the design’s performance under the applicable test duties. Routine tests concern the supplied units. Factory acceptance and site commissioning add the checks agreed for the project. Treating them as one unspecified “test certificate” leaves the buyer unsure what will arrive.
State the required standard and edition, then ask for the report references that apply to the offered model and ratings. IEC 62271-100:2021+AMD1:2024 covers AC circuit-breakers within its stated scope and includes direct making-breaking test methods. Requirements for the complete switchgear assembly need to be addressed separately where it is also being supplied.
Agree the routine-test records, drawings, manuals and spare-parts information to be delivered. If tests will be witnessed, identify the witness points, notice arrangements and acceptance responsibility. These details affect both price and schedule, so they belong in the enquiry.
Who will handle engineering questions and after-sales support?
Find out who prepares the drawings, answers application questions, supplies spares and handles warranty claims. A distributor and a manufacturer may provide different services. If authorisation is claimed, ask for current confirmation covering the supplier’s legal entity, territory and product scope, and verify it through the manufacturer’s official channel.
The article on evaluating industrial VCB suppliers covers supplier assessment in more detail. For the quotation itself, name the engineering deliverables needed rather than relying on a general promise of technical support.
How specific should the model description be?
It should identify the version being priced and its included options. Fuerte’s ZW20-12/630-20 product information includes source data, mechanism and controller options, and more than one breaking-current entry. The offer needs to state the selected configuration so the buyer can connect the quoted price to the required duty.
Before releasing the order, resolve outstanding differences, approve the drawings and confirm the acceptance documents. If a requirement changes, have the quotation updated. That is simpler than trying to reconstruct later which version of the equipment both parties understood was being purchased.
Frequently asked questions
What is the current standard lead time by voltage class?
Voltage class alone does not determine lead time. Request a dated offer for the model, options, quantity and documents required, with the starting and ending milestones stated.
What vacuum circuit breakers are stocked for quick shipment?
The supplier must confirm current availability for the exact configuration. Check included accessories, document readiness and reservation terms as well as the main breaker.
What warranty coverage is offered for an outdoor vacuum circuit breaker?
Ask for the written terms, including duration, starting date, installation conditions, exclusions and claim procedure. Coverage varies by supplier and contract.
What tests are performed on a vacuum circuit breaker?
Type tests cover design capabilities, while routine tests cover supplied units. Factory acceptance and site commissioning should be listed separately in the project test plan.
What technical specifications should a VCB supplier provide?
The offer should identify ratings, construction, interfaces, controls, service conditions and relevant test evidence. Agree the drawings and manuals that will follow with the equipment.
What IEC standard applies to vacuum circuit breakers?
IEC 62271-100 applies to AC circuit-breakers within its scope. The project may also require standards for the assembly, particular switching duties and installation.
References
- IEC 62271-100:2021+AMD1:2024 — Alternating-current circuit-breakers.
- ABB — Primary Vacuum Circuit Breakers, different application duties; reviewed 16 October 2026.
- Tavrida Electric — Vacuum Circuit Breaker: Fundamentals, interrupter and mechanism construction; reviewed 16 October 2026.
Summary
A clear enquiry lets the buyer compare what will actually be supplied. Begin with the electrical duty and installation, then define controls, accessories, tests and documents. Compare price after the included items and exceptions are understood. For delivery, establish both the starting milestone and the point at which the supplier’s commitment is complete. Written stock and warranty terms are equally important when they affect the purchasing decision. Fuerte can assess an enquiry more effectively when it includes the rating schedule, drawings, quantities and required delivery documents. Resolving those details before ordering gives the project a clearer basis for manufacture, acceptance and handover.