1
1. Introduction
In most photovoltaic systems, the DC isolator is integrated into the DC/AC power inverter. After
switching off the DC isolator, the cables between the DC solar modules and DC/AC power inverter
running through the building are still subject to up to 1000 Vdc. In the event of a fire, firefighters are
exposed to a very serious source of potential danger. The S-BOX provides the solution to this problem.
It directly disconnects the DC current in close proximity to the solar modules and creates a safer
situation for firefighters.
Basic Features:
·AC power shut down=automatic DC power shut down
·Auto reset when AC power is back=DC power is back
·Easy to install
2. System Advantages
2.1 Easy installation
S-BOX can be installed without disassembling the shell.
2.2 Gain valuable time in case of a fire
S-BOX works according to standard international firefighter routines, resulting in valuable time lost in AC
power is shut down, S-BOX will automatically switch off and isolate DC cables running between the PV
modules and the inverter. Firefighters only have to follow their regular routine and do not have to waste
valuable time eliminating the risk of DC power still present at these cables. In case the AC power is not
shut down and the temperature reaches 70°C at the S-BOX unit it will automatically shut down the DC
power as extra safety system.
2.3 Completely isolate PV modules
S-BOX is powered by a motorized X-type switch and can therefore be located directly at the PV
modules. This minimizes the amount of cabling with dangerous high voltage and leads to a completely
powerless situation in the house, maximizing safety when needed.
2.4 Auto reset
A power down situation can occur at any time and for many reasons. S-BOX has an auto reset function.
S-BOX automatically switches off if the regular AC power is down for more than 6 sec and automatically
switches on when the regular AC power is on again. No manual reset is necessary every time the power
has been down! After check of the safety situation and when the AC main power is reconnected
automatically the S-BOX will switch on the DC power.
2.5 For use in industrial and residential photovoltaic installations
By using this standard concept unit for either 1 or 2 strings it is possible to combine unlimited number of
units to fix every size of installation. As option it is possible to connect all units to the same AC source in
order to create a separate DC on-off operation by switching this specific AC source on-off that will
operate all units at the same time. Again, reset is done automatically AC on = DC on, AC off = DC off.
These units can be easily retrofitted to existing or new installations.
2.6 Indication of DC switch status
S-BOX provides remote and in-place instructions for customers to confirm the status of the switch.
Users can determine whether the switch is closed by providing a light on the machine or by connecting
the dry contact (FB1, FB2) to the remote indicator light.
Note: The dry contact (FB1, FB2) can be used a circuit 24Vdc - 300mA max.
