NCR RealPOS 70XRT 7403 - Appendix A: Transient Protection; AC Power Line Transient Protection

Appendix A: Transient Protection
AC Power Line Transient Protection
Intheprocessofpowerdistribution,transientelectricalenergy(including,butnot
limitedto,lightningstrikes,intermittentshortcircuits,andswitchingtransients)can
beintroducedontopowerlines.Suchtransientenergycanbeverydamagingto
electronichardware,andcanalsocausedatacorruption.Underthesecircumstances,
NCRrecommendstheuse
ofACpowertransientsuppressors.Suchprotection
devicesareintendedtoguardagainstpowerlinetransientsthatcanresultin
hardwaredamageandvarioussystemorprogramerrors.
Improvementofanydeficienciesinpowerqualityisacustomerresponsibility.
Malfunctionand/orcomponentfailureasaresultofpowerqualitypro blems
are/isnot
coveredbytheNCRMaintenanceAgreement.NCRacceptsnoliabilityforanysuch
occurrencenorforitsconsequences.
Whenpowertransientsuppressionisrequired,thesuppressorsusedshouldmeetthe
followingminimumrequirements:
• Dissipateenergytomatchtheappropriateapplicationcategoriesasdefinedby
IEEEStandard587.
•
Beofthevoltagelimiting(clipping),ortrackingfiltertype.Thesuppressormust
notclampthevoltagetozero,andmustself‐recoverafterthepassageofthe
transient.Thesuppressormaybeofthehybridtypeconstructionthatmakesuse
ofvarioustechnologiesinordertomeetspeedand
dissipationrequirements.
• Uponfailure,exhibitapositiveindicationofitsfailuresuchasablownfuseor
trippedbreaker.
• Belistedbytheacceptedsafetyorganizationforthecountryinvolved(UL,CSA,
VDE,ETL,andsoon)andtheinstallationmustconformtolocal,state,and
nationalelectricalcodes
andregulations.
A