Buildings & infrastructure
Review transformer-supply and cabinet requirements, then distinguish load switching, fuse-combination protection, isolation and earthing.
Product selection detailsBuilding service distribution. Illustrative application context.
Building and infrastructure distribution can bring transformer supply, load switching and maintenance isolation into the same cabinet arrangement. Begin with the single-line diagram and identify the function assigned to each component. A load switch, a load-switch/fuse combination, a disconnector and an earthing switch serve different duties; their names should not be treated as alternative labels for one device.
The FKN12 reference identifies terminal and box-type substations in urban and rural distribution, including transformer and cable applications. The Liqiang catalogue includes buildings and residential developments among its general application contexts. VQLA documentation also identifies public facilities and high-rise building supply networks. Select the components for the required electrical duty, cabinet design and operating sequence.
Provide the single-line diagram, transformer or circuit requirements, rated voltage and current, and the required switching and protection duties. Identify where a circuit breaker, a load switch or a fuse-combination arrangement is being considered. The component choice follows the assigned electrical function, rather than the building type or the appearance of the enclosure.
Use the exact product designation when comparing FKN with FKRN, or FZN with FZRN. The manuals describe bare load switches and fuse-combination equipment separately. Where fuses form part of the specified arrangement, include their requirements and the relevant cabinet interfaces. Do not assign the fault-clearing duty of the combination to a bare load switch without confirming its own specified function.
Identify the required isolation and earthing positions and how they relate to the cabinet operating sequence. The GN30 manual describes no-load isolation, while JN15 documentation describes the earthing function. An earthing blade is associated with the stated GN30-12D version, rather than every GN30 configuration. Match the selected components and operation to the installation drawing.
Provide mounting dimensions, phase spacing, terminal positions and the available operating space. Show the shaft position and operating direction where these interfaces connect to the cabinet. Include the access and interlock requirements in the same drawing so that the switch position, mechanism and enclosure can be reviewed together before confirming the equipment arrangement.
State the operating method, supply and any required auxiliary contacts or control interfaces. Where an integrated three-position breaker is proposed, review its own VQL or VQLA construction and operating sequence instead of substituting separate-component assumptions. Identify the required manual and drawing edition, and state the exact configuration where inspection records or test reports are part of the specification.
These product samples illustrate specific structures. Confirm the ordered designation and interfaces independently.
The FKN12 manual describes transformer, cable and distribution-line applications, particularly terminal and box-type substations. Review the load-switch duty and cabinet interfaces; where a fuse combination is specified, use the corresponding FKRN designation and documentation.
Shown: an FKN12 product sample.
Review load-switch families
Review the vacuum load-switch arrangement for the specified circuit and cabinet. The manual separately describes the FZN load switch and FZRN fuse combination. Operating method, earthing and control requirements should be matched to the exact selected configuration.
Shown: a vacuum load-switch and fuse-combination assembly.
Compare vacuum load switches
Review the cabinet earthing function, phase spacing, shaft and mounting interfaces against the manual and drawing. GN19, GN27 and GN30 disconnectors belong to the same product category but provide a distinct isolation function that must be specified separately.
Shown: JN15 earthing equipment.
Review isolation and earthingA cabinet layout becomes more useful when it shows the duty of each component and the intended operating sequence. Use those references to coordinate the enclosure and switching equipment.
Single-line diagram, transformer or circuit duty, and allocation of switching and protection functions.
Mounting, phase spacing, terminals, shafts, operating directions and available space.
Interlock sequence, control interfaces, exact model designation and required documentation.
Use the manual for the exact component being selected. A load-switch manual does not establish the operating function of a disconnector, and an earthing-switch reference does not define a complete cabinet. Where VQLA equipment is being considered for a building supply network, consult its separate three-position reference.
