Do You Need an RCD Type B for a Home EV Charger?
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Yes — EV Easy recommends an RCD Type B on every EV charger circuit. Type B detects DC residual current; a standard Type AC breaker cannot.
How is RCD Type B different from a standard earth-leakage breaker?
According to the RCCB Tongou x EV Easy Type B product data: Type B detects three kinds of residual current — AC, pulsating DC and smooth DC. A standard Type AC breaker cannot detect DC.
| Type | Residual current detected |
|---|---|
| Type AC (standard breaker) | AC |
| Type B | AC · Pulsating DC · Smooth DC |
Why should an EV charger circuit use Type B?
An EV charger feeds the car's charging system, which contains power-conversion circuitry. A leakage fault in such a circuit may include a DC component, so a device that detects DC is needed. Our FAQ therefore recommends a 40A breaker with RCD Type B for 32A chargers, and a 20A breaker with RCD Type B for 16A chargers (see the FAQ).
Which chargers have RCD Type B built in?
According to the product data in our system at the time of writing:
| Model | Leakage protection |
|---|---|
| Model Black Gen 2 | RCD Type B (DC 6 mA detection) built into the unit |
| Model Q | RCD Type B circuit built into the unit |
| Model U Gen 2 | Charger detects AC 30 mA + DC 6 mA residual current |
Every EV Easy installation adds a separate RCD Type B breaker in the consumer unit, whether or not the charger has built-in leakage detection, so the charger circuit has an extra layer of protection at the source.
Installing the charger yourself — which breaker do you need?
Fit a Type B residual-current breaker in the consumer unit ahead of the charger. EV Easy offers two options, depending on your supply (both 40A, 30mA):
| Model | Supply | Price |
|---|---|---|
| RCCB Tongou x EV Easy Type B, 2-pole | 1-phase 230V | THB 1,790 |
| RCCB Tongou x EV Easy Type B, 4-pole | 3-phase 400V | THB 2,690 |
The 4-pole model suits 11 kW and 22 kW chargers wired on a three-phase circuit. Prices are for the product only and do not include installation.
What else should be checked before installation?
The RCD is only one part of the charging circuit. Also check the meter size, main cable and free space in the consumer unit. See Preparing your electrical system before installing an EV charger and Circuit 1 vs Circuit 2. Real example: Model Q 22 kW three-phase install in Pattaya. Background: What is an RCD?
Summary
- An EV charger circuit should have an RCD Type B because it detects DC residual current, which Type AC cannot.
- Every EV Easy installation includes a Type B breaker in the consumer unit.
- Not sure what your home needs? Send photos of your meter and consumer unit via LINE @eveasy or call 093-359-2207 (Mon–Fri 10:00–17:30 · Sat 12:30–17:30).
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Which charger can your home take?
The right charger depends on your meter size, your existing electrical panel and the distance from the panel to your parking spot — not just your car model. Send photos of your panel and parking spot on LINE and our team will give you a first assessment, or see the four installation options and their pros and cons on our installation service page.