uring encapsulated spark gap and/or replaceable varistor modules, the three devices protect the more vulnerable DC side of commonly used earth free and mid point earthed PV systems. The range includes: the 7P.26.9.420, providing 2 varistors and 1 spark gap for 420V DC systems; the 7P.23.9.700, providing 3 varistors for 700V DC systems and the 7P.23.9.000, providing 3 varistors for 1000V DC systems.
Each device integrates both a visual indicator and a signalling contact to warn when a varistor module needs replacing. Connection to the signalling contact is via a convenient plug-in terminal block. The SPDs comply with EN 61643-11 standard and can be 35mm rail (EN 60715) mounted.
Finder's introduction of a range of SPDs tailored to the needs of PV installations comes at a time when UK government Feed-In Tariffs (FITs) appear to have stimulated a step increase in interest in PV system in the country. The UK is now the fastest growing market for PV solar energy installations, estimated to produce 96MW of electricity in 2010 compared with 6MW in 2009.
At the same time, a prospective revision of the UK wiring regulations, placing far more emphasis on the provision of protection from electrical surges, has meant there is a resurgence of interest in associated products, in particular varistor and spark gap type SPDs.
PV panels at Finder's prime manufacturing site in Almese near Turin in North West Italy have been producing an output power of 55kW since early 2009, equating to 61,000 kWh/year. So pleased with the performance, the company has this month commissioned a further 60kW of PV panels, which of course will be protected by the new 7P Series surge arresters.
Constructed using multicrystalline silicon PV modules, Finder's initial PV system is calculated to have reduced CO2 emissions by about 37 tons/year, achieving annual cost savings of around 11 TOE (tonnes of oil equivalent).