Regarding this topic, I believe that the NEC requires that portable generators
have the neutral grounded when the power level is 5000 watts or higher. This
would explain why many generators do not have this provision.
Also, I believe that GFCI's could be effectively used ... even if the neutral
is grounded. They don't "measure" leakage through the grounded conductor but
sample the degree of balance between the neutral and hot conductors. If the
imbalance is greater than about 5 mA, they trip. The assumption is that the
imbalance is current flowing via the grounded conductor.
I recommend that GFCI's be used on all 120 volt circuits that are in "wet
locations" which includes outdoor circuitry. Although in the US OSHA rules
only apply to employer-employee sites (work settings like construction sites)
use of GFCI's is considered "good electrical safety practice".
Jim Woods, W7PUP
(Retired Safety Engineer)
Grants Pass, OR
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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