A second charging station requires more than an extra cable and machine. We also look at how the chargers' protections work together with the protections in your electrical cabinet. This way the entire installation remains well protected.
What is the difference between type A and type B?
A RCD compares the current leaving with the current returning. In the event of an error, some of it may flow away through soil. The RCD interrupts the supply when that fault current reaches the trip conditions. A circuit breaker has a different task: to protect against overload and short circuit.
Type A recognizes alternating and pulsating fault currents. An electric car contains electronics that can also cause a smooth direct current fault, DC. Too much of that DC can make a regular Type A less sensitive, sometimes called "blinding." He may then not respond sufficiently in the event of another error. Type B is also designed for smooth DC fault currents.
What is already included in an Easee Charge Max or Pro?
The official Easee product sheets confirm two built-in functions for both models: a type A residual-current protection of 30 mA AC according to EN 60947-2 and an RDC-DD for 6 mA DC according to IEC 62955, part 9.9. The latter monitors the DC fault current of its own charger and interrupts the power supply when the shutdown conditions are reached.
At one charging point, an extra type B is therefore not automatically necessary for the DC protection of that charging point. The power cable, circuit breaker and any overhead differentials must match the entire installation.
- 30 mA AC: the built-in type A protection for AC fault currents.
- 6 mA DC: Separate detection of smooth DC fault current via the RDC-DD.
Two chargers: 5 mA + 4 mA together can become 9 mA.
Suppose two chargers simultaneously have a DC leak with the same direction. The first has 5 mA DC leakage current, the second 4 mA. Each charger only sees its own leakage current. Both values remain below 6 mA, so neither needs to trip based on its own DC detection.
Due to the common protection in front of the two chargers, 5 + 4 = 9 mA DC can run. That joint current can affect the operation of a regular type A. The built-in 30 mA AC protection makes each charger not a guardian of the total DC leakage current of all chargers together.
| Where? | DC leakage current | What does the protection device detect? |
|---|---|---|
| Charger 1 | 5 mA | Below the nominal 6 mA DC value of the self-detection. |
| Charger 2 | 4 mA | Also below the nominal 6 mA DC value. |
| Leading together | 9 mA | Above 6 mA DC: an ordinary type A is not automatically suitable here. |
Why then a type B in the lead from two chargers?
By 'at the head' we mean before the branches to the chargers. For two or more Easee chargers behind the same regular type A, we provide a suitable type B, unless the manufacturer demonstrably allows the complete combination. Volta describes this condition for a common type A. Two separate charging circuits can also share the same main RCD.
Type B continues to operate correctly at smooth DC fault currents within its specifications. It therefore does not necessarily switch off at 9 mA: that depends on its sensitivity and characteristics. Any protections that precede this type B must also be suitable.
What does that mean for your installation?
If you want to install a second charging point, please also indicate which charger is already there. With the diagrams and clear photos of the closed electrical cabinet we can start the preparation. We look at the existing protections, the connection and the desired expansion and explain any adjustments in your quote.
You don't have to choose a RCD or open the case yourself. We tailor the implementation to your installation and the applicable regulations. The independent inspection body assesses the conformity of the installation carried out.
Short answer
Frequently asked questions
Which residual-current protection is already in an Easee Charge Max or Pro?
Both models have an integrated type A protection of 30 mA AC and an RDC-DD for 6 mA DC. The electrical protection of the power cable and the rest of the installation is assessed separately.
Do I always need an external type B RCD for a single Easee charger?
No. With a Charge Max or Pro, type B is not automatically required for the DC protection of the charging point: the 6 mA DC detection is built-in. We also check the overhead RCD, other connected devices and the manufacturer's instructions.
Why do you provide a type B in the lead for two chargers?
Behind a common RCD, DC leakage currents can add up. With 5 mA on the first and 4 mA on the second charger, together 9 mA DC can flow through that protection. Without a demonstrably approved manufacturer combination, we provide a suitable type B upstream.
Does a type B RCD always trip at 9 mA DC?
No. Type B is designed to operate correctly even with smooth DC fault currents. The selected sensitivity and device characteristics determine when it switches off. The example of 9 mA shows why an ordinary type A can be affected; it does not specify a shutdown threshold for type B.
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