Inside a commercial charging cabinet you will find a power stage, a main switching contactor, a controller, an energy meter, residual-current and surge protection, cooling hardware, a user interface with an RFID or payment reader, a communications module, and the cable-and-connector assembly — all in a sealed, rated enclosure. For an engineering buyer, the cabinet is best read as a system of blocks: each block does one job, and each has a specification and a test record you can ask for.
Key Takeaways
- A commercial cabinet is a system of blocks: power stage, contactor, controller, meter, protection, cooling, interface, communications, enclosure.
- AC and DC cabinets share most blocks; the DC power path — rectifier modules and DC switching — is the real difference.
- Every block has a specification and evidence behind it — ask for both at specification stage.
- Fans, filters and cable assemblies belong in the procurement conversation from the start.
The Power Path: Where AC and DC Cabinets Differ
In an AC station the supply passes through the cabinet to the car, which converts it on board — so the cabinet’s power hardware is about switching, protection and measurement, not conversion. In a DC cabinet the heavy work moves inside: rectifier modules convert AC to DC, usually as identical modules in parallel, so output scales and the unit runs at reduced power with one module out of service. The output side then adds DC-rated contactors and, on the fastest units, a cooled cable assembly. The component count, the heat and the service concept all follow from where conversion happens; our guide to how DC fast chargers work covers the conversion itself.
Control, Metering and Communication
A controller board runs the session: connector signals in, contactor commands out, protection devices watched, and a link to the outside world. An energy meter records what each session delivered — the figure billing stands on, so operators in regulated markets ask whether it is a certified billing-grade unit. The communications module (Ethernet, Wi-Fi or a cellular modem) links the station to its management platform — the software side (access, pricing, monitoring) is set out in our explainer on how commercial charging stations work. The user interface completes the block: a display, an RFID reader and, on public units, a payment terminal.
Protection and Thermal Hardware: The Blocks to Verify
| Component | Its job | What a buyer verifies |
|---|---|---|
| Main contactor | Connects and cuts the output; the switch every protection acts through | Rated current and duty for the design; how a stuck-closed (welded) contact is detected |
| Residual-current protection | Detects leakage, including smooth DC leakage from charging electronics | Where it lives — in the unit or upstream — and the standard its evidence cites |
| Surge protection device | Clamps supply voltage spikes before they reach the electronics | That one is fitted, its type, and how its end-of-life is indicated |
| Cooling: fans, filters, heaters | Keeps power electronics within temperature limits, summer and winter | Filter access for service, fan replacement concept, condensation control |
| Enclosure and cable assembly | Seals the hardware against dust and water; carries the current to the car | The stated ingress rating, cable length and connector standard for your market |
Specifying a Cabinet: The EVDANCE Conversation
EVDANCE is a Shenzhen manufacturer founded in 2011, exporting to 30+ countries, with private label from 100 units and a 3-year standard warranty. Its two cabinet products state their headline facts on their pages: the EV-AC03201T dual-connector AC station (up to 43 kW shared across two Type 2 connectors, OCPP 1.6J, RFID, IP54) and the EV-RHDC30K-L compact DC fast charger (22 kW DC, OCPP 1.6J, IP54). Component choices sit behind those pages in the design file — the same file that holds the model’s bill of materials on the manufacturing side. Ask for the component-level documentation behind the model you are buying (protection architecture, metering evidence, cooling and service concept) as part of the commercial charging specification, and get the answers in writing via the contact page before the order, not after delivery.
Frequently Asked Questions
Is the component list the same in AC and DC cabinets?
Broadly, yes for control, protection, metering and communications. The power path differs: a DC cabinet adds rectifier modules and DC-side switching — most of its size, cost and cooling.
Which components does a maintenance plan actually touch?
Typically the service items: fans and filters, the cable and connector assembly, and switching hardware over long service. Our commercial charger maintenance checklist sets out the operator-level checks; component replacement belongs to the manufacturer or a qualified service partner.
Can modules be swapped later to raise a station’s power?
Only where the design was built for it — some DC cabinets accept additional power modules; many do not. Ask whether the model is modular and what an upgrade involves, and get the answer in the quotation.
Related Reading
- How Do Commercial EV Charging Stations Work?
- How Do DC Fast Chargers Work?
- Commercial EV Charger Maintenance Checklist
- What Is the Best Commercial EV Charging Station? How to Choose
