Data and information technology - OBO Bettermann

Planning aid, generalinformationWhat are transient surges?Transient surge voltages: 1 = Voltage drops/short interruptions, 2 = Harmonic waves due to slow and fast voltage changes, 3 = Temporary voltage increases,4 = Switching surges, 5 = Lightning surgesTransient surge voltages are briefvoltage peaks lasting microseconds,which may be a multiple ofthe attached mains nominal voltage.The largest voltage peaks in thelow-voltage consumer network arecaused by lightning discharges.The high energy content of lightningsurges when a direct strikehits the external lightning protectionsystem or a low-voltage openwireline usually causes − withoutinternal lightning and surge protection− total outage of the connectedconsumers and damage to theinsulation. Yet induced voltagepeaks in building installations andenergy or data cable supply cablescan also reach many timesthe nominal operating voltage.Switching surges, too, which infact do not cause such high voltagepeaks as lightning dischargesbut occur much more frequently,can result in immediate systemfailure. As a rule, switching surgesamount to twice to three times theoperating voltage, lightning surges,on the other hand, can sometimesreach 20 times the nominal voltagevalue and transport a high energycontent. Often, failures occuronly after a time delay as the agingprocess of electronic componentsin the affected devices triggeredby smaller transient surgescauses insidious damage. A numberof different protection measuresare required. These dependon the exact cause and/or impactpoint of the lightning discharge.02 TBS-Katalog_2010_Neuer_Stand / en / 30/03/2010 (LLExport_00986)10 OBO TBS