found issue w/impproper appliance wiring immediately
installed this baby to protect a 240V 30A dryer circuit..
kicked off several times after I plugged in the GE dryer
took connection cover off.. found Big box store installer did not wire dryer correctly for 4 wire installation & used no wire grommet holder @ the wire box entrance..
don't trust a big box outfit to ever do an install properly..
maybe not unsafe but certainly incorrect
we now enjoy gfi protection on our dryer circuit should a impending disaster loom..
installation took a bit longer because I had to move the DP switch down in the main panel so as not to block my also installed extended neutral bar set screw accessibility
this necessitated a circuit extension exterior work box ( orange wire ) as my existing neutral wasn't long enough to make the new breaker location
THIS GFI CAN NOT BE USED ON CIRCUITS THAT NEUTRAL TO GROUND
therefore, most all 3 wire circuits and equipment neutral frame grounded CAN NOT BE PROTECTED