A 3-phase coffret de distribution is a metal enclosure housing three-phase breakers, busbars, and terminals that route power to downstream circuits. For electrical cabinet OEMs, the enclosure itself — its steel gauge, material grade, and forming tolerances — is what determines mechanical strength, fit with internal components, and how the finished panel performs in the field.

What Is a 3-Phase Distribution Box?

The term covers any enclosure built to house three-phase distribution hardware: incoming supply terminals, breakers or fuses for each phase, busbars, and often metering or monitoring gear. Search results for this term are dominated by finished-product listings — pre-built boxes ready to bolt onto a wall, or rental units for temporary site power. Those pages answer “what do I buy” for someone wiring a single installation.
They don’t answer a different question: what determines whether the enclosure itself holds up once it’s populated with switchgear, mounted outdoors, or produced at volume for a product line. That’s the OEM side of the term, and it’s the side finished-box sellers have no reason to cover.

The Enclosure Does More Than Hold Wires

Cabinet OEMs and switchgear manufacturers don’t buy a distribution box as a finished unit. They buy or fabricate the enclosure — the formed steel shell, door, mounting panel, and cable entry points — and populate it with their own electrical assembly. At that stage the enclosure is a mechanical component with its own requirements: it has to hold its shape under door and hardware load, seal against the environment it’s rated for, and match the internal layout the cabinet designer has already drawn.
Get the gauge or material wrong and the problem doesn’t show up on a spec sheet. It shows up as door sag after a few hundred open-close cycles, panel flex that misaligns breaker mounting holes, or corrosion at the seams on an outdoor unit that was speced for indoor use.

Material and Gauge Choices, by the Numbers

Cold-formed electrical cabinet profiles are typically produced from one of six material grades, each suited to a different exposure or cost target:

Specifying a Custom Enclosure: 5 Steps

For OEM builders working with a cold-forming supplier rather than buying a catalog box, the process typically runs:

1. Submit cabinet or profile drawings with dimensions and mounting requirements.
2. Specify material grade and thickness within the supplier’s supported range (0.2–10 mm on Chenlong’s line).
3. Confirm production volume and required forming speed — relevant for scheduling, since capacity here scales up to 50 m/min.
4. Select servo feeder configuration; Chenlong’s line supports Yaskawa, Delta, or customized feeder setups depending on punching complexity.
5. Confirm certification needs, lead time, and payment terms before order confirmation.

Skipping step 1 — starting from a generic spec instead of an actual cabinet drawing — is the most common reason a first production run doesn’t fit on assembly.

Certification, Lead Time, and Cost

Chenlong states ISO9001, CE, and SGS approvals at the company level. Certificate numbers, issuing bodies, and exact scope aren’t published, so that claim should be read as a company-level positioning statement rather than a verifiable per-machine certification — worth confirming directly with the supplier before it’s cited in a procurement document.
For context on what CE actually requires: machinery placed on the EU market currently falls under Machinery Directive 2006/42/EC, with Regulation (EU) 2023/1230 replacing that framework starting January 20, 2027. That transition matters for any OEM sourcing production equipment for EU-bound cabinets, separate from the finished-box question.
On cost: there’s no published price list for this profile line. Chenlong prices these projects individually based on the customer’s drawings, material spec, dimensions, required speed, punching needs, and automation level — so “how much” only gets answered after a drawing is submitted. What is published are the commercial terms: 30% deposit at order confirmation, balance after inspection and before shipment, T/T or L/C accepted, standard lead time of 20–30 business days, and 40–60 business days for custom configurations.

Custom Fabrication vs. Finished Boxes

Compared with the finished-enclosure and rental-box listings that typically rank for this search term, this is a different transaction. A finished-box purchase starts from a catalog SKU and ships as-is. Custom cold-formed fabrication starts from a cabinet drawing and produces an enclosure built to that layout — which is the only version of this that actually helps a switchgear OEM, since a catalog box wasn’t designed around their internal component placement to begin with.
The trade-off is timeline. A finished box can ship same-week; a custom production run, even at the fast end, runs 20–30 business days standard and longer for custom configurations. For a one-off installation, that’s a real disadvantage. For an OEM building the same cabinet across a product line, it’s the difference between fitting internal hardware without rework and forcing a design around a box that wasn’t made for it.

FAQ

What thickness range is typical for a 3-phase distribution box enclosure?

On Chenlong’s production line for this application, rolling thickness spans 0.2–10 mm, with the specific figure depending on cabinet size, load, and installation environment rather than a single standard number.

Can these enclosure profiles be produced in stainless steel?

Yes — supported materials include SPCC, SPHC, SGCC, SUS (stainless), aluminum, and SECC, selected according to the project’s exposure and corrosion requirements.

 How long does a custom production run take?

Standard equipment lead time is 20–30 business days; custom configurations run 40–60 business days. Expedited production may be available for urgent orders.

Does Chenlong sell finished distribution boxes, or just the profiles and production equipment?

The published product line covers cold-formed steel profiles and the production equipment that makes them (decoiling through cutting, punching, and stacking), not finished retail distribution boxes.

What certification applies to the equipment or profiles?

Chenlong states ISO9001, CE, and SGS approvals at the company level. Certificate numbers and exact scope aren’t published on the reviewed pages, so this should be confirmed directly for any project requiring documented compliance.