59
Electrical connection
EN
7.2.2 External AC input protections
General shematic to identify the position of AC protection devices.
Id
A
B
C
D
F
E
Parameter
Description
A
Medium voltage network
B
Medium voltage breaker
C
Low voltage network
D
Automatic circuit breaker
E
EVSE
F
Residual current Device (RCD) (opt.)
7.2.2.1 Overcurrent protection
An external overcurrent protection device shall be installed to protect medium voltage transformer-EVSE line.
In weak grids the AC voltage may vary from nominal voltage; in these conditions EVSE works with
higher input current then nominal one. This information has to be taken in consideration to
properly select the overcurrent protection device.
Table below provides the technical data to size the overcurrent protection correctly:
AC input
voltage [V]
AC input
current [A]
Terra 60
Nom. 400
125
Min. 360 (400 - 10%)
138
Terra 360
Nom. 400
560
Min. 360 (400 - 10%)
626
7.2.2.2 Residual current device (RCD) protection
HAZARDOUS VOLTAGE
If the enforced local regulation of electrical installations require the use of a residual Current
Device (RCD), a Type B or B+, with adjustable residual operating current (I
∆
n [mA]), is mandatory.
NOTE
EVSE models equipped with Mode 3 output have built-in RCD type DD + RCD type A protecting
the AC ouput. There is no need of addtional protections to comply with IEC 62955.
NOTE
When using residual-current device with a lower operating current (I
∆
n), there is a risk of false
tripping of the residual-current device, depending on the system design.
NOTE
In the case of systems which consist of several EVSE connected to a single protection,
adjustment of tripping value and time, may be required.
In case of installation of a residual current protection device, this shall meet the following characteristics in
order to prevent false protection tripping:
RCD Specifications
Terra 60
Terra 360
Type
B / B+
Suggested sensitivity I
∆
n
300 mA
