Groundingāoptionaldedicateddrainwire
FrequenciesemittedfromequipmentsuchasswitchmodepowersuppliesorMF/HFtransmittersetc.
cancauseinterferencewithyourMFD
āstouchscreen.Ifyouexperienceissueswithtouchscreen
performance,ļ¬ttinganadditionaldedicateddrainwirecanresolvetheissue.
Note:
Theadditionalwiresupplementsthedrainwire(shield)thatispartoftheproductā
spowercable
andshouldONL Ybeusedwhentouchscreeninterferenceisobserved.
Useasmallļ¬atbladescrewdrivertoremovethecoveroverthegroundingscrewhole .
Connectoneendoftheadditionaldrainwire(notsupplied)toyourproduct.
Connecttheotherendoftheadditionaldrainwiretothesamepointasthepowercabledrain
wire(shield).Thiswillbeeitherthevessel'sRFgroundpoint,oronvesselswithoutanRFground
system,thenegativebatteryterminal.
Thedcpowersystemshouldbeeither:
ā¢Negativegrounded,withthenegativebatteryterminalconnectedtothevessel'sground;or
ā¢Floating,withneitherbatteryterminalconnectedtothevessel'sground.
Ifseveralitemsrequiregrounding,theymayļ¬rstbeconnectedtoasinglelocalpoint(e.g.withina
switchpanel),withthispointconnectedviaasingle,appropriately-ratedconductor,tothevesselās
commonRFgroundpoint.
Implementation
Thepreferredminimumrequirementforthepathtogroundisviaaļ¬attinnedcopperbraid,with
a30Arating(1/4inch)orgreater.Ifthisisnotpossible,anequivalentstrandedwireconductor
maybeused,ratedasfollows:
ā¢forrunsof<1m(3ft),use6mm
2
(#10AWG)orgreater.
ā¢forrunsof>1m(3ft),use8mm
2
(#8AWG)orgreater.
Inanygroundingsystem,alwayskeepthelengthofconnectingbraidorwiresasshortaspossible.
References
ā¢ISO10133/13297
ā¢BMEAcodeofpractice
ā¢NMEA0400
Connections39