Title :
Blocking diodes and fuses in low-voltage PV systems
Author :
Wiles, John C. ; King, David L.
Author_Institution :
Southwest Technol Dev. Inst., New Mexico State Univ., Las Cruces, NM, USA
fDate :
29 Sep-3 Oct 1997
Abstract :
Instructions and labels supplied with listed PV modules and the requirements of the National Electrical Code (NEC) dictate that a series fuse shall be used to protect the module against backfeed currents. Few of the hundreds of thousands of low-voltage (12, 24, and 48-volt) stand-alone photovoltaic (PV) power systems use series fuses on each module or string of modules. Tests and simulations at the Southwest Technology Development Institute (TDI) and at Sandia National Laboratories (SNL) have established that the absence of these fuses can pose significant fire and safety hazards even on 12-volt PV systems. If the system has sufficient backfeed voltage and current, it is possible that a ground fault in the wiring or inside a module can result in the destruction of a PV module
Keywords :
electric fuses; photovoltaic power systems; power semiconductor diodes; safety; solar cell arrays; 12 V; 24 V; 48 V; National Electrical Code; Sandia National Laboratories; Southwest Technology Development Institut; backfeed current; backfeed currents protection; backfeed voltage; blocking diodes; fire hazards; fuses; ground fault; listed PV modules; low-voltage PV systems; safety hazards; stand-alone photovoltaic power systems; Diodes; Fires; Fuses; Laboratories; National electric code; Photovoltaic systems; Power system protection; Power system simulation; Solar power generation; System testing;
Conference_Titel :
Photovoltaic Specialists Conference, 1997., Conference Record of the Twenty-Sixth IEEE
Conference_Location :
Anaheim, CA
Print_ISBN :
0-7803-3767-0
DOI :
10.1109/PVSC.1997.654281
