A portable charger’s protection lives in the control box on its cable — the IC-CPD. Into a sealed enclosure the size of a paperback go residual-current sensing, a switch that can cut the full load, temperature monitoring and the session electronics. What fits inside, and what is left to the circuit, is the central design decision — the first thing a brand buyer should pin down in writing.
Key Takeaways
- A control box packs control, fault detection, switching and monitoring into one sealed enclosure — every function trades against space and heat.
- Protection is layered between box and circuit; the design must state the split.
- Product pages state ratings and sealing; the protection set of a specific model is proven by its test documentation, not assumed.
- For private-label orders, put the protection configuration in the written specification before production.
What Has to Fit Inside the Box
The jobs compete for one small volume: the box advertises the current, confirms the car is connected, and only then lets power flow — while the protective devices sit around that brain. Each costs space, heat or complexity.
| Function | What does the job | Design cost |
|---|---|---|
| Session control and signalling | Control electronics that set the offered current and supervise the connection | Board space and firmware in a box that also carries full load current |
| Residual-current (earth-fault) detection | A sensing element around the conductors, watched by a trip circuit | A bulky sensor, and the DC fault question shapes the whole design |
| Load switching | A relay or contactor rated to break the full charging current | Heat at every operation; a steady share of the enclosure volume |
| Temperature monitoring | Sensors watching the box and, on many designs, the wall-plug end | Sensor positions compete with the power parts for places that read true |
EV charging can produce smooth DC residual currents that blind simpler detectors, which is why the choice between Type A, Type B and added 6 mA DC detection — set out in our explainer on RCD protection for EV chargers — is a design decision, not a detail.
Three Pressures That Fight Each Other
Space against coverage. Every added device makes the box bigger and harder to hang safely from a socket. The volume comes from somewhere — usually the switching device or the sensor, the two parts that least forgive being shrunk.
Heat against sealing. Charging is a continuous load held for hours; the relay and electronics warm the box from inside. A sealed enclosure has no airflow, so heat must conduct out through the housing — the tighter the seal, the more deliberate that path must be.
Sealing against service. A box potted or welded shut survives weather and drops, but nothing inside can be repaired. Sound designs accept that: the cord set is built, tested and replaced as one unit, and its devices are chosen for the set’s life.
What the Box Does Not Carry Alone
No control box is the whole story: the circuit’s breaker still guards the wiring. On some designs, part of the fault-detection job is left to an upstream device — the manual states the split, and it differs by market: North American practice speaks of GFCI protection, as our guide to whether an EV charger needs GFCI protection explains. The car’s own systems form the last layer. A specification that does not say where each protection lives is incomplete, whichever brand is on the enclosure.
EVDANCE Portables, Read by Their Pages
EVDANCE’s portable range shows why the written page matters. The EV-ACS3210T 32A NACS portable charger is listed at about 7.7 kW with current adjustable in six steps from 10 to 32 A and an IP66 rating. The EV-AC04001U 40A J1772 portable charger is listed at 9.6 kW with SAE J1772 and IP66. Its page states no protection devices — so a buyer requests the model’s protection documentation instead of assuming. That request is normal trade practice: EVDANCE offers private label from 100 units, and the protection configuration belongs in the written specification agreed through the contact page before production.
Frequently Asked Questions
Does every portable charger have earth-fault protection built into the box?
No. Designs differ by model and target market, and some rely partly on protection in the installation. The listing and the model’s test report state what is inside; a licensed electrician confirms what the circuit must add.
Why not simply make the control box bigger and fit everything?
Because the box hangs on a cable at a socket: size adds weight, strain and handling problems, and a larger sealed box must still shed the same heat. What matters is the documented protection set, not the size.
What document proves a protection claim?
A type-test report or certificate from an accredited laboratory naming the exact model. A brochure line is a claim; the laboratory document is the evidence.
Related Reading
- RCD Protection for EV Chargers: Type A, Type B and 6 mA DC Detection Explained
- Does an EV Charger Need GFCI Protection?
- Mode 2 vs Mode 3 Charging: What IEC 61851 Means for Portable EV Chargers
