Is there a problem with hooking two GFCI protected components in
series?  (IE plug a GFCI protected hair dryer into a GFCI protected
outlet.  If so please explain problem.

dave010901-ga:

As long as you are dealing with GFCIs that are designed for the
voltage and current of the actual load being protected, then having
multiple Ground Fault Circuit Interrupters in series will not affect
the ability of the GFCIs to protect the device. In an ideal situation,
the GFCI closest to the device will trip first as it should detect the
difference in current flow between the Hot and Neutral conductors
first; however, given differences in manufacturing tolerances, any one
of the GFCIs can be more sensitive than the rest and trip first.

You can learn more about how GFCIs work on the following webpage:

http://www.codecheck.com/gfci_principal.htm

The only problem that I can think of when using GFCIs in series is in
troubleshooting why a GFCI trips, when one does trip. However, that is
actually a good problem, as it requires you to investigate the problem
thoroughly to find the cause. The cause can be a true wiring problem,
or simply a GFCI in need of replacement due to reaching the end of its
service life.

If you can provide some more details about any specific situation or
concern you have, I may be able to provide more useful information in
a formal Answer.

Regards,

aht-ga
Google Answers Researcher

GFCI's are "voltage-rated" devices.  When you connect multiple devices
to the line, they are in "parallel", not "series".  All of the devices
will respond to an over voltage event at essentially the same time, if
they have the same voltage rating (breakover, given manufacturing
tolerances).  Multiple devices, for the most part, improve the
protection margins of connected equipment.  They do this by providing
a parallel path for voltage discharge to ground (curent flow and
energy dissipation) when an over voltage event occurs.  The only
downside is that you may have to reset multiple GFCI's; but your
equipment will benefit from the extra protection.

Please disregard my last comment.  For some reason, I thought your
question was about "surge supression".  The earlier comments were
quiet accurate regarding GFCI's.