1. Where the EV charging station distribution cabinet sits in the site Main incoming line → EV charging station → vehicle
Current path at a charging site:Transformer (10kV/0.4kV) → main distribution cabinet → EV charging station distribution cabinet (branching) → EV charging station (AC) → vehicle.
The EV charging station distribution cabinet is responsible fordistributing power from the main distribution cabinet to each charging station, and also providesmetering / surge / leakageprotection.
2. How to calculate capacity Formula + quick-reference table
Capacity calculation formula:Pc = N × Pmax × Kc
Where Pc is the total capacity of the EV charging station distribution cabinet, N is the number of charging stations, Pmax is the maximum power per station, and Kc is the diversity factor (0.5–0.8, depending on the application).
| Application | N (number of stations) | Pmax (kW) | Kc | Total capacity (kVA) |
|---|---|---|---|---|
| Residential 7kW AC charging | 10 | 7 | 0.5 | 35 |
| Commercial 60kW DC fast charging | 5 | 60 | 0.7 | 210 |
| Commercial 120kW DC fast charging | 5 | 120 | 0.7 | 420 |
| Transit bus 180kW high-power charging | 3 | 180 | 0.8 | 432 |
Example: 10 x 7 kW AC chargers in a residential community, Kc = 0.5, total capacity 35 kVA — select a 100 kVA transformer + 100 A main incoming + 10 outgoing circuits at 32 A.
3. Dual-source transfer: does a charging station need it? Depends on the scenario
Dual-source transfer (ATS) at a charging station isDepends on the scenario-dependent:
| Application | Whether to use dual-source transfer | Why |
|---|---|---|
| Residential / commercial AC charging | Not recommended | High cost; AC charging users can accept delayed charging |
| Taxi / ride-hailing DC fast charging | Recommended | Drivers are time-pressed; downtime losses are high |
| Bus / logistics dedicated station | Mandatory | Fixed operating hours; downtime disrupts departures |
Dual-source options: utility power + BESS cabinet / utility power + generator, ATS transfer time ≤ 0.5 s. Zhejiang Golden Unicorn cansupply ATS dual-source transfer cabinets, MOQ 1 unit.
4. Metering scheme: master meter + sub-meters + DC side What operators care about most
A charging station's3-level metering:
- Master meter: main incoming at the transformer side, for utility settlement
- Sub-meter: one per outgoing circuit in the EV charging distribution cabinet, for the operator to account for power use at each charger
- DC meter(optional): inside the DC charger, for accurate billing
Zhejiang Golden Unicorn distribution cabinetsinclude sub-meters as standard(one three-phase multifunction meter per outgoing circuit), with Modbus / DL/T 645 protocol upload support.
5. Surge / lightning protection: mandatory at charging stations Mandatory for outdoor charging stations
Outdoor charging stationsmust be fitted with SPDs(surge protective devices) against induced lightning and switching surges. Configuration:
- Main incoming: Type 1 + Type 2 in series (In = 25 kA, Imax = 40 kA, Up ≤ 1.5 kV)
- Each outgoing circuit:Type 2(In=20kA,Up ≤ 1.5kV)
Zhejiang Golden Unicorn EV charging distribution cabinetsship with a Type 2 SPD as standard, with Type 1 added on the outdoor version.
6. Factory Photos: 4 Images of an EV Charging Station Distribution Cabinet (shop floor photos)
FAQ FAQ
Does an EV charging station distribution cabinet need ground fault protection?
It is mandatory.(Required by GB/T 51313.) Each outgoing circuit is fitted with 30mA ground fault protection; a 300mA time-delayed ground fault device can be added on the main incoming as backup.
Does an EV charging station distribution cabinet need surge protection?
Mandatory for outdoor installations, recommended for indoor.Outdoor charging stations are heavily exposed to lightning-induced surges, so Type 1 + Type 2 protection in series; indoor installations need only Type 2.
What enclosure material is used for an EV charging station distribution cabinet?
Outdoor charging stations 304 stainless steel, IP65; indoor or residential applications can step down to powder-coated cold-rolled steel, IP54. Zhejiang Golden Unicorn builds both; the outdoor version carries a 30% price premium.
Does an EV charging station distribution cabinet require 3C certification?
3C is not mandatory for the assembled cabinet; the internal components (breakers, contactors, ground fault devices) require 3C.NB/T 33002 It is an industry standard, and we recommend following it on compliance-driven projects.
Can Zhejiang Golden Unicorn build a complete EV charging station?
Zhejiang Golden Unicorn suppliesEV charging station distribution cabinet (power side) and EV charging station control cabinet (signal side), but we do not manufacture charging modules.The complete unit is supplied by the charging station manufacturer(TELD, Star Charge, Wanma, etc.); Zhejiang Golden Unicorn can coordinate the connection.
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