8
External relay for the backup power supply
Connecting an external relay
Through use of an external relay, some of the single 
phase loads can be connected to the AC LOCAL OUT 
connection on the PowerRouter, which provides backup 
power during a power outage. This creates a backup 
system with a switch-over time of ≥ 1 second providing 
the connected loads with an backup with a stable 230 
VAC/50 Hz output. The power provided during a power 
outage comes simultaneously from the solar energy 
that is being generated at that moment and from the 
batteries. It is important to note, however, that only 
a portion of the loads can be supplied with backup 
power, because the reserve capacity of a self-use 
system is limited by the available solar energy and the 
size of the battery bank.
A benecial aspect of this switching conguration is 
that loads draw power from the grid whenever the 
PowerRouter is restarted or in standby.
The PowerRouter has two sets of congurable potential-free contacts. When a grid outage occurs, loads are 
switched to backup power via an external relay. An advantage to this system is that there is no current owing 
through the relay coil during normal use. In addition, the PowerRouter controls the exact moment of switch-
over, which enables it to bring the current provided at AC LOCAL OUT into synch with the mains current as 
the grid power is restored. Another advantage is that delay times can be congured, using the PowerRouter 
Software Installation Tool*. This makes it possible to prevent the backup power provision from responding to 
brief power interruptions (brown-outs).
*For more information about the settings, please consult the PowerRouter application guideline - Software Installation Tool, which you can 
download from our website.
Technical data - external relay
The external relay can be any standard, commercially available relay with the technical specications shown 
below.
Europe except UK  UK
> Coil voltage: 230 VAC  > Coil voltage: 230 VAC
> Contact ratings: 40 A for both N/O and N/C contacts  > Contact ratings: 95 A for both N/O and N/C contacts
> Contact conguration: 2 contacts, or 2 N/Os and 2 N/Cs  > Contact conguration: 2 contacts, or 2 N/Os and 2 N/Cs
> Contact gap: ≥ 3.2 mm  > Contact gap: ≥ 3.2 mm
As indicated in the picture above, only single-phase consumers can be connected to AC LOCAL OUT. When 
producing backup power, the PowerRouter generates its own AC output which cannot be synchronised with the 
other two phases.
Figure 7: Connecting an external relay for backup power
0 1 7 7 6 3
0 1 7 7 6 3
tuo lacol CAdirg CA
L3
N
LNCNO
N
L
L2L1N
L3
R1 R2
3 4
L2
L1
L
N
N
R7 R8
5 6
A1 A2