First, RCDs such as used in UK, are not available in N America. In
NA, they are called GFCIs or AFGI, and are located on branch circuits.

Second, an RCD, if doing anything, could only cure symptoms - would
not solve the problem.

We know incoming electricity voltage was monitored long term and
remained within 5%. We assume appliance damage is due to over voltage.
Therefore many have accurately speculated that a loose neutral may
exist.

What would the RCD do? Nothing. Excessive voltage would not cause
currents to take a new path to earth - what is necessary to trip the
RCD (GFCI). A loose neutral only means half the house has excessive
voltage while other half has diminished voltage. Currents entering and
leaving the building remains constant.

Second, an RCD still would not fix the loose neutral. Fix the
problem; don't cure its symptoms.

But again, we are assuming loose neutral because we are assuming
damage due to excessive voltage. We have not yet established why
damage occurs which is again why we first must identify the problem
before trying to cure its symptoms (using an RCD or power strip
protector), or before trying to correcct it.

Dave Plowman (News) wrote:
Surely what's needed is an RCD device which will trip if there is any
unbalance between line and neutral?