Establish the equipment boundary before requesting a quote
An outdoor vacuum circuit breaker, an automatic recloser and an indoor metal-enclosed switchgear panel are different procurement objects. The interrupting medium alone does not define the assembly, installation method, control package or protection duty. Start by marking the device on the single-line diagram and stating whether it is a pole-mounted feeder device, a substation breaker or equipment inside an enclosure.
Jinxing's linked medium-voltage switchgear pages describe panel families. Those pages and their panel report images should not be read as proof that a standalone outdoor breaker or pole-mounted recloser is available. Confirm the supply boundary first; for an assembly project, identify any outdoor device being supplied by the utility, EPC contractor or another equipment vendor.
Decide which operating function the project needs
| Project requirement | What the buyer must clarify |
|---|---|
| Interrupt a fault on instruction from protection | Breaker duty, relay scheme and reliable trip supply |
| Automatically restore supply after a transient fault | Reclosing sequence, protection controller and utility operating policy |
| Provide a visible or otherwise approved isolation function | Separate isolation arrangement and operating procedure |
| Switch a cable-fed substation within an enclosure | Complete switchgear assembly, cable interface and access requirements |
| Send status and commands to a control centre | Communications, points list, local/remote authority and auxiliary power |
The word 'automatic' should not substitute for a functional description. Reclosing on an overhead circuit may have a different purpose and approval process from restoring a cable-fed industrial plant. The utility or protection engineer must determine whether reclosing is permitted and how it coordinates with downstream protection.
Separate electrical duty from outdoor suitability
Record system voltage and frequency, highest voltage requirements, normal current and the prospective short-circuit duty. Ask the designer to identify the required operating sequence and special switching duties. A rated current value says little about whether the device can interrupt the required fault under the specified conditions.
Outdoor suitability needs its own schedule. Include altitude, temperature range, pollution and salt exposure, condensation, solar exposure and mounting conditions. The support structure, terminal orientation, cable or overhead-line connections, surge protection and earthing interface also need an owner. Do not assume that placing an indoor panel under a canopy makes it a qualified outdoor assembly.
For example, an EPC may buy an indoor switchgear line while the utility supplies the outdoor connection-point device. In that case the tender needs an interface drawing: termination points, protection signals, trip responsibilities and the boundary of each vendor's tests. Ordering both packages under the loose label '11 kV breaker' leaves those interfaces unresolved.
Check controls and evidence together
The quotation should identify the operating mechanism, close and trip supply, energy storage, position indication, local controls and any remote controller. Specify behavior on loss of auxiliary power and on restoration. If batteries or chargers are required, state the responsibility for sizing, supply, alarms and maintenance.
Ask for evidence covering the actual equipment type, rating and configuration. IEC 62271-100 addresses AC circuit breakers, including indoor and outdoor designs within its scope. IEC 62271-111 addresses automatic circuit reclosers within its stated scope. Neither standard title proves that a proposed product has passed a particular test. Request the document identity and scope, then compare them with the quoted equipment.
Information for a useful enquiry
- Single-line diagram with the connection point and equipment owner marked.
- Required breaker, recloser, isolation and protection functions.
- Electrical duties, environment, mounting and terminal arrangement.
- Auxiliary supply, protection controller and communications interface.
- Applicable utility specification, approval process and requested test documents.
- Clear distinction between standalone outdoor equipment and the indoor switchgear package.
Use the contact page to discuss an integrated switchgear project and confirm the available supply scope. Do not use a panel quotation as a substitute for an unconfirmed outdoor-device offer.
Standards scope references
Confirm the edition and amendments required by the project before specifying compliance.