When installing an EV charger, safety is a top priority. One critical component in any EV charging system is the Residual Current Device (RCD), which protects against electric shocks and fire hazards caused by electrical leakage. However, using the wrong RCD can lead to serious risks.
In this article, we explain:
The difference between AC 30mA and AC 30mA + DC 6mA RCDs
How they affect EV charger installation
The dangers of non-compatible installations
________________________________________
What is an RCD, and Why Does it Matter?
An RCD (Residual Current Device) is a safety device that trips the circuit when it detects leakage current. In EV charging, this is crucial because both AC and DC leakage currents can occur, depending on the EV’s onboard charger and electrical system.
The wrong RCD selection can lead to a false sense of security—a situation where the system appears functional but may not actually protect against faults.
________________________________________
AC 30mA vs. AC 30mA + DC 6mA RCD – What’s the Difference?
Please see attached picture below for comparison chart
Why Does DC Leakage Matter?
Some EVs and chargers produce small DC leakage currents
If a standard AC 30mA RCD is used, it may get “blinded” and stop detecting faults
This increases the risk of electric shock or fire
________________________________________
How RCD Choice Affects Installation
When installing an EV charger, the required RCD depends on the charger’s built-in features:
If the charger has built-in DC leakage detection → AC 30mA RCD (Type A) is acceptable
If the charger does NOT have built-in DC leakage detection → AC 30mA + DC 6mA RCD is required
Teison-IGP Smart Mini chargers already include DC leakage protection, meaning they work with a standard AC 30mA Type A RCD. However, always check the specs before installing.
________________________________________
What Happens If You Use the Wrong RCD?
Using only an AC 30mA RCD when DC leakage is present can cause:
No protection against DC faults – Risk of electric shock
RCD blinding – The safety system may fail to trip, leading to overheating or fire
Regulatory non-compliance – Failure to meet Suruhanjaya Tenaga (ST) and IEC 61851-1 standards
Voided warranties and insurance risks – Incorrect installation can invalidate coverage
A properly installed RCD is not just a legal requirement—it’s an investment in safety.
________________________________________
How to Ensure a Safe EV Charger Installation
Check the charger specifications – If it lacks DC leakage protection, you need an AC 30mA + DC 6mA RCD.
Follow Malaysian electrical regulations – Installers must comply with Suruhanjaya Tenaga (ST) and IEC standards.
Engage a qualified EV charger installer – This prevents dangerous and costly mistakes.
At Innovative Green Power (IGP), we ensure every EV charger installation meets safety standards and proper RCD requirements.
