On Fri, 04 Dec 2015 13:12:26 -0700, Don Y
wrote:

On 12/4/2015 8:28 AM, wrote:

But, that will wait until at least the weekend. I have many other
things that need to get done in the short term and the forecast suggests
I've got at least a week before temperatures begin to approach the
lows that are troublesome...

You can't get more "structured" that just plugging a comparable load
into the receptacle that fails (without involving extension cords tree
lights etc)

What if the nature of the load has an impact on the results?
E.g., say I plug a large power supply for that has an insane
turn-on transient in but idles at just a few watts (switching
losses). Smaller load but bigger turn on transient.

Or, drag out a longer spool of wire to use as the extension cord?

Or, try the toaster oven on one and lights on another?

Don't add variables to the analysis. Just come up with a
consistent test strategy and apply it consistently.

E.g., the second set of 3 strings that I dragged out to
mimic an "equivalent load" (as the first set that are
presently IN the tree) is only conceptually an identical
load. Making observations with one set in one case and
another set in another case isn't apples-apples.
Even though it might (and quite probably is!) appear to
be so.


For the purposes if this discussion, a hair dryer would do just fine.
If it trips, you know you have a problem in the wall or receptacle
string. Then try it at the end of the extension cord. If still no
trip, there is a problem with your lights.

The idea that an incandescent light will trip a GFCI in normal
operation (no faults) is ludicrous. That tiny surge while the filament
is heating up is well inside the trip curve of any breaker I have ever
seen. It would certainly be less than the heat up time of a hair dryer
element.