‰  NOW 20 WPM  ‰  TEXT IS FROM NOVEMBER 2012 QST  PAGE 65‰

LACK OF SIGNIFICANT HIGH FREQUENCY HARMONICS KEEP THE CAPACITIVE LEAKAGE
CURRENTS LOW.  GFCIS ARE SET TO IGNORE ABOUT 5 MA OF LEAKAGE CURRENT THIS
IS HIGH ENOUGH TO PREVENT FALSE TRIPS YET STILL LOW ENOUGH TO PROTECT
PEOPLE.  THE OUTPUT OF AN INVERTER IS LESS SINUSOIDAL THAN COMMERCIAL POWER
AND SOME HIGHER FREQUENCIES ESCAPE EVEN THOUGH THE OUTPUT IS SOMEWHAT
FILTERED.  THESE HIGH FREQUENCIES CAUSE HIGHER CAPACITIVE LEAKAGE CURRENTS
AND THE OFFSET BETWEEN THE SWITCHING TIMES OF THE HOT AND NEUTRAL LEADS
MEANS THE LEAKAGE CURRENTS IN THE POWER LEADS ARE NOT IN PHASE AND CANNOT
BALANCE TO CANCEL EACH OTHER.  THE GFCI SEES THESE CURRENTS AND TRIPS.  IT
IS ALSO IMPORTANT TO REMEMBER THAT THE NEUTRAL OUTPUT LEAD FROM AN INVERTER
IS LIKELY HOT.  MODERN GFCIS INTERRUPT BOTH THE HOT AND NEUTRAL LEADS WHEN
‰  END OF 20 WPM TEXT  ‰  QST DE W1AW  ƒ