What Happens Before Your Power Distribution Equipment Ships?

When a distribution project is tendered, the visible part is the equipment list. What actually decides whether the station is energised on schedule is the work done before the equipment is shipped — scheme matching, structural design, integrated assembly, wiring and factory commissioning. In this article, "equipment" means one integrated package: high and low voltage switchgear cabinets, ring main units, and the compact stations built around them. Zhejiang Deyan Electric Co., Ltd. (DEYAN ELECTRIC) walks through the sequence.

I. Turning Project Conditions into a Scheme

Model selection is not picking a cabinet from a catalogue. It is systematic equipment matching around load capacity, installation site, environmental conditions, budget and delivery cycle. At this stage the primary main wiring, cabinet layout and basic secondary wiring schemes must be planned together, so that all complete equipment in the station is mutually compatible. Deyan Electric's technical team provides preliminary scheme design and parameter selection support before any cabinet is committed to production.

II. Keeping the Design Inside Proven Scope

Two constraints protect both schedule and quality. First, verify the type test reports and qualification documents of the corresponding cabinet models, so the equipment complies with industrial standards and meets project acceptance requirements. Second, stay within stably mass-producible models: standard cabinet types also keep sufficient stocked standardized parts, which matters for later spare parts procurement and maintenance. Non-standard customized schemes are evaluated only for genuine size or structural demands, with the increased cycle time and cost assessed upfront rather than discovered during production.

III. Integrated Assembly and Wiring, Not Just Cabinet Supply

For primary-secondary integrated solutions, sensors and monitoring units are embedded inside the cabinet and matched with an external intelligent distribution terminal. The manufacturer's responsibility here is not limited to supplying a cabinet: Deyan Electric handles cabinet structural design, complete assembly of primary equipment, wiring integration and overall commissioning before delivery. Where intelligent terminals and monitoring components are purchased auxiliary parts, the interface between supplied equipment and purchased components is defined during design and assembly — not left to be resolved on site.

IV. Factory Commissioning, Up to Whole-Unit Delivery

Overall factory commissioning means the primary wiring, secondary circuits and interlocks are tested as a complete system before shipment, so faults are found in the workshop instead of during energisation. The same logic extends from a single cabinet to a complete station, because compact stations are themselves factory products.

Box-type substations are prefabricated as a whole unit and ready for immediate installation, while prefabricated cabin substations are assembled on site from factory-made modules. Because site work is reduced to foundation preparation, positioning, connection and commissioning, the on-site construction period is shortened and quality no longer depends on site weather or temporary site labour.

V. What to Confirm Before Shipment

Before the equipment leaves the factory, four items are worth confirming in writing:

1. The agreed scheme reflects load capacity, installation site, environmental conditions, budget and delivery cycle.
2. Type test reports and qualification documents exist for each cabinet model.
3. The scope boundary between supplied complete equipment and purchased auxiliary components is clearly drawn.
4. Factory commissioning records, wiring integration checks and the remaining site work list are handed over together.

This is what turns a purchase order into a station that can be energised on schedule.

About Zhejiang Deyan Electric Co., Ltd.

Zhejiang Deyan Electric Co., Ltd., located in the Economic Development Zone of Yueqing City, Zhejiang Province, specializes in the R&D, production and service of industrial electrical appliances. Its core products include box-type substations, prefabricated cabins, ring main units, gas-insulated switchgears, photovoltaic step-up box substations, high and low voltage switch cabinets and cable branch boxes, serving urban grid upgrading, industrial park distribution, distributed PV stations, energy storage and rail transit. The company supports customized primary schemes, integrated assembly and overall factory commissioning. To plan an integrated distribution scheme or arrange factory commissioning, please contact Deyan Electric.