How to switch solar panels

Rutronik presents the FTR-J2 and FTR-K2W relay from Fujitsu as a solution to enable remote switching and emergency cut-off of the solar panel. These relays, connecting the solar panel to the converter, are able to switch DC power. The new relays are available at distributor Rutronik now.
The FTR-J2 DC relay is capable of switching 450VDC, 10A. It measures just 24mm(L)x23.5(W)x27mm(H). To be able to switch high DC voltages despite small dimensions, Fujitsu has designed two strong magnets within the relay to extinguish the severe breaking arc. The FTR-J2 is a powerful, compact and reliable solution for solar appliances that need to switch high DC voltage.

The new FTR-K2W DC relay is also suitable to be integrated in the converter of solar systems to switch on/off the DC voltage generated by the solar panel. Its main feature is its big contact gap of >6mm. Furthermore the relay is capable of switching 60V DC, 30A.

Fujitsus FTR-K2G and new developed FTR-K3-WG and FTR-F4G AC relays can function as interface between the solar converter and the power grid. These AC relays can be used in compliance with DIN VDE 0126-1-1. According to this safety standard the circuit break function between the solar converter and the power grid must have a contact gap 1.5mm at each pole.

The FTR-F4G with relatively lower power switching capabilities is recommended for the small solar panel systems, where the FTR-K2G is most useful for relatively large solar panel systems.