Figure 14: Inverter DC Connections
Selecting a Residual Current Device (RCD)
IMPORTANT SAFETY FEATURE
All SolarEdge inverters incorporate a certified internal Residual Current Device
(RCD) in order to protect against possible electrocution and fire hazard in case
of a malfunction in the PV array, cables or inverter. There are two trip
thresholds for the RCD as required for certification (DIN VDE 0126-1-1). The
default value for electrocution protection is 30 mA, and for slow rising current
is 300 mA.
If an external RCD is required by local regulations, check which type of RCD is required
for the relevant electric code. Install the residual-current device (RCD) in accordance
with the applicable local standards and directives. SolarEdge recommends using a type-
A RCD. The recommended RCD value is 100 mA or 300 mA unless a lower value is
required by the specific local electric codes. When required by local regulations, the use
of an RCD type B is permitted.
NOTE
For multiple inverters, an RCD per inverter is required.
In installations where the local electric code requires an RCD with a lower leakage
setting, the discharge current might result in nuisance tripping of the external RCD. The
following steps are recommended to avoid nuisance tripping of the external RCD:
Select the appropriate RCD for correct operation of the installation: An RCD with a
rating of 30 mA may actually trip at a leakage as low as 15 mA (according to IEC
61008). High quality RCDs will typically trip at a value closer to their rating.
Configure the trip voltage of the inverter's internal RCD to a lower value than the
trip current of the external RCD. The internal RCD will trip if the current is higher
than the allowed current, but because the internal inverter RCD automatically resets
when the residual currents are low it saves the manual reset.
Chapter 4: Connecting the AC and the Strings to the Inverter
29
Single Phase Inverter with HD-Wave Technology Installation MAN-01-00540-1.0
