The attached Fire Hazard declaration helps to motivate lower fire risk when using micro inverters

1. www.relink.com.mt Birkirkara, 2015 May 30th
The RELINK micro­inverters significantly contribute the reduction of the fire hazard in PV installations, the micro­inverters strongly contribute to
the achievement of the safety objectives required by the European Community regulations, when it comes to the fire hazard risk valuation.
STRING & CENTRAL INVERTERS RELINK MICRO INVERTERS
PROBLEM DESCRIPTION RISK DESCRIPTION RISK
DC cables routing The DC cables (avarage lenght between 15 to 60
meters) probably run inside the building.
HIGH The DC cables lenght is less than 1 meter.
Never run inside the building.
NONE
DC circuit unprotected Up the DC String box. The unprotected energized
circuit lenght varyes between 15 and 60 meters
depending on the strings lenght.
HIGH Up to micro­inverter. The unprotected
energized circuti lenght is in any
circumstance less than 1 meter.
LOW
Energized circuit During daylight, in case of fire or problems when the
AC main opens, the DC strings will be in any
circumstance energized (300 ÷ 900V)
MEDIUM­HIGH During daylight, in case of fire or problems
when the AC main opens. The DC circuit
energized (<60V) the PV mosule cable (only
1 meter).
LOW
Atmosferic induced
overvoltage
Strings with long lenght (from 15 to 60 mt) increase
the area of the electrical “coil”, increasing the risk of
atmosferic induced overvoltages that could result in
an electrical arc..
MEDIUM­HIGH String with reduced lenght (1 mt) drastically
reduces the area of the electrical “coil”,
statistically reducing risk of atmosferic
induced overvoltages.
LOW
Cause of fire Is demonstrated that use of DC surge arresters,
fuses and diodes in DC string box and lack of
maintenaince increse causes of fire.
MEDIUM­HIGH Not Present NONE
Electrical injuries risk DC Operation Voltages VDC = 300 ÷ 900V HIGH DC operation Voltages VDC < 60 V NONE
RELINK Limited
Vincenzo di Gennaro ­ CTO