Changeover cabinets
- Capacity: PC-class double-throw up to 1600 A; CB-class per breaker frame (with short-circuit protection)
- Enclosure: GGD module dimensions, can be sectioned and through-busbar connected with main incoming / feeder cabinets
- Logic: auto-transfer with auto-recovery / auto-transfer without recovery / mutual backup, loss-of-voltage detection delay settable
- Generator interface: issues start signal on loss of voltage, connects once frequency and voltage are stable
- Monitoring: dual-source voltage and current, transfer count and fault log, RS485 reporting optional
Specifications
The table below covers 80% of factory distribution room cases. Anything outside it we can still build — those are engineered items, quoted separately, with an indicative price the same day.
| Type | GGD module-dimension floor-standing cabinet, sectionable (through-busbar between cabinets) |
|---|---|
| Standard sizes (W×D×H) | 800×600×2200 / 1000×800×2200 mm, custom build available |
| Enclosure construction | 2.0 mm cold-rolled carbon steel, operating mechanism front-door mounted, padlock + handle dual lock |
| IP rating | IP30 / IP54 (standard distribution room / humid environment) |
| Operating face | Dual-source power indication, transfer position indication, manual / auto selector |
| Cable entry | Dual-source bottom / side entry, feeder busbar can run through |
| Rated voltage | AC 380V / 400V, 50 Hz |
|---|---|
| PC-class | Integrated dual-source transfer switch up to 1600 A, no overcurrent protection (provided upstream) |
| CB class | Two molded-case / air circuit breakers + mechanical interlock + motor operator, with protection |
| Transfer Time | PC class: as fast as tens of milliseconds; CB class: 1–3 s |
| Loss-of-voltage detection | Three-phase voltage monitoring; undervoltage / phase loss / overvoltage detection delay adjustable 0.5–5 s |
| Generator interface | Volt-free start dry contact + transfer after generator stable confirmation |
| Monitoring and reporting | Dual-circuit current and voltage, transfer count, fault log; RS485 / Modbus optional |
| Component brands | Schneider / ABB / Chint / dedicated ATS manufacturers; customer-specified brands supported |
| Dual utility main / standby type | Two utility incoming lines, main source with automatic transfer to standby; standard for data rooms and production lines |
|---|---|
| Utility + generator type | Starts the generator on loss of voltage, transfers after stable, automatic return on restoration |
| Mutual standby type | Two sources at equal priority, selected automatically based on availability |
| Sectional type | ATS cabinet + GGD incoming / outgoing sections assembled into one lineup; integrated distribution room |
| End-of-line branch type | Feeder circuits after transfer; essential and non-essential loads output on separate columns |
| Assembly standard | GB/T 7251.1 / IEC 61439-1; ATS devices comply with GB/T 14048.11 |
|---|---|
| Interlock verification | PC-class contact mutual exclusion and CB-class mechanical interlock verified unit by unit |
| Routine tests (every unit) | Insulation resistance, dielectric withstand, and full simulated loss-of-voltage transfer logic tests |
| Temperature rise | Contact and busbar connection points ≤70 K |
| Documents with shipment | System diagram, transfer logic description, setting table, BOM, test report |
Five steps to specify your run
A configuration summary is generated as you go. It travels with your inquiry, saving a round of confirmation.
Build details
Systems have been in service for decades, and the failure points are always the same few: poor busbar contact, water ingress at the door seal, high temperature rise in the correction cabinet, and mis-phased outgoing feeders. The six hard rules below are written for exactly these points — every cabinet can be traced to them.
Factory-prefabricated busbar sections
When joined to a GGD lineup, inter-cabinet copper busbars are prefabricated at the factory and bolted on site; busbar cross-section matches the main cabinet, and through-bus positions are dielectric-tested together with the full section.
Setting table ships with the unit
Undervoltage detection, transfer delay and restore confirmation are set per system and written into a setting table affixed inside the cabinet door; on site you verify, not re-tune.
Color-coded main and backup
Main and backup incoming busbars and terminals are color-coded and tagged, so emergency manual operation does not switch the wrong circuit.
Every operation is logged
Transfer counts and fault records are optional: contacts have a service life, and after tens of thousands of operations they need servicing — with a counter you can schedule it, instead of relying on a veteran's memory.
Full logic tested unit by unit
A variac simulates undervoltage, phase loss and overvoltage; auto-transfer, auto-restore and generator handshake logic are all energized end to end, and the timing sequence is recorded in the report.
One lever, one motion
If automatic control fails, the handle switches manually in a single step, and the operating opening is padlocked — automatic stays automatic, but the last step is always left to a person.
Photos & enclosure construction
Below are photos taken in our own shop — from the complete unit down to the internal busbars and secondary wiring. Every build detail can be checked item by item.
Image key: 01–05 are shop photos (the numbers match the shot list). The line drawing shows the front elevation of the enclosure; dimensions match the specification table above.
Where these cabinets go
These are the routine applications — we can talk scheme and configuration directly. For the industry view, see the industry pages.
Server Rooms & Data Centers
Dual-utility transfer at the distribution room level, feeding downstream panelboards.
Factory main distribution room
Joined to a GGD lineup, with integrated main and backup incoming feeds.
Hospitals and industrial parks
Transfer of the main incoming feed for critical loads (specific requirements confirmed per project).
Commercial complexes
Mutual backup and transfer between transformers.
Continuous production lines
Main/backup protection for processes sensitive to voltage sags.
Power plant sites
Distribution room solution for automatic transfer between utility power and generator sets.
Commercial terms
Specification dated September 2026; quotations follow this.
| Drawings & design | Free |
| MOQ | 1 unit (5 or more recommended for production) |
| Production lead time | 15-25 days after drawing approval |
| on-time delivery | 98% |
| Warranty | 12 months |
| Loading port | Ningbo / Shanghai, China |
| Component brands | Schneider / ABB / Siemens / Chint |
| Factory visit & dispatch confirmation | Factory visits welcome; finished-cabinet photos and video before dispatch |
| Capacity | 5,800+ units / year |
Documents for your engineering team
Selection manual, outline dimensions and RFQ checklist — for the customer's electrical engineer. All three documents are being organized by product line; download links go live once complete.
Six questions procurement and electrical engineers ask most
How do I choose between this and a wall-mounted ATS box?
It comes down to installation location and capacity: for main/backup transfer in a distribution room, above 630 A, or when joining a GGD lineup, use the floor-standing cabinet; for local transfer at end loads, below 160 A, use the wall-mounted box. The two often work together — the cabinet handles main transfer, the box handles the end load.
Does a PC-class transfer cabinet need upstream protection?
Yes: a PC-class switch has no overcurrent protection of its own, so the upstream breaker is sized to the load. This is also why PC-class is so reliable — simple construction with no extra tripping stages. In our solution we lay out the upstream/downstream protection coordination clearly.
Can two transformers back each other up?
Yes, with mutual-backup logic: both feeds share the same priority, and whichever is healthy carries the load; a fault on one feed triggers automatic full transfer, and after recovery it returns per the settings. Size the busbars and switches for the full load — don't cut corners by sizing for half.
Can sensitive equipment ride through a transfer?
PC-class transfer takes tens of milliseconds, which most equipment won't notice, but for IT and precision electronics we still recommend downstream UPS; CB-class transfer means 1–3 seconds of power loss and requires UPS ride-through. The transfer cabinet solves 'no source interruption'; the UPS solves 'no power interruption' — the two work as layers.
Can it record why a transfer happened?
Optional: transfer cause (undervoltage / phase loss / overvoltage / abnormal frequency) and timestamp logging, reported to the supervisory system over RS485. Fault tracing has evidence, not guesswork.
What's the benefit of joining the cabinet to a GGD lineup?
Busbars are factory pre-fabricated as continuous runs (bolted on site only), with a single dielectric withstand test across the full section and consistent appearance and operator interface. When cabinets come from two separate suppliers, busbar interface alignment and split responsibility are both traps — multi-section lineup from one factory gets it right in one pass.
Other cabinet types in the same main circuit
Related products use color-block placeholders for now (product photos not yet complete; they will be replaced together). Internal links will be filled in once live URLs are confirmed.
Send the electrical room system diagram and we will configure the transfer sections to match
Send your electrical room system diagram or power supply parameters and we will provide a free transfer scheme and setting recommendations · Quotation within 24 hours. Direct from the source factory, MOQ 1 unit, 15–25 day delivery, 1-year warranty.
ISO 9001:2015 · CE(LVD+EMC) · CQC · IP65
When you write, include: single-line diagram or primary scheme, switch room layout, load list, and component brand requirements. You do not need complete drawings — capacity and cabinet type are enough to start.