You have been provided a combination of myths and truths
combined with a mentality that 'it worked before, therefore it
will always work'. Proper grounding for all buildings has
been necessary for 30 years - due to something very new called
transistors.
Primary reason for that third prong is why its called safety
ground. Any short that would threaten human life must instead
trip a circuit breaker. Two wire outlets do not provide that
protection. For human safety on two wire circuits (a kludge
solution), we install a GFCI that must also be specifically
labeled as such on each wall receptacle with three words as
required by the code book - "No Equipment Ground".
Safety ground also serves other functions. For some
electronic equipment, it carries off leakage currents. A
GFCIed two wire circuit will not do that. If two three wire
appliances don't share the same three wire ground pin, then
damage may result. This was why mechanical switch boxes (one
computer shares multiple printers) damaged HP LaserJet II
printers. Second lesser reason for grounding involves how
electronic hardware operates with attached components. Safety
ground provides a common voltage reference so that electronics
is not damaged by voltage leakages.
To solve this 'leakage' problem, all computer components
(computer, monitor, printer) must connect to same $3+ power
strip (and not a surge protector strip) that includes an all
so important 15 amp circuit breaker. Every power strip must
have that circuit breaker. Then the power strip connects to a
GFCIed wall receptacle. We have addressed human safety and
transistor safety problems created by two wire outlets.
Static electricity is not eliminated by earth ground.
Static is electric charges on both sides of shoes. To
discharge that 'capacitor', make a complete circuit - as
taught in second grade science. The complete and destructive
circuit through computer may be up arm, through computer, out
via table top or AC electric wire, into carpet, and back to
shoe. This circuit does not go through transistors if using
static protective wrist straps. Things considered not
conductive at 100 volts can be conductive at 15,000 volts.
Conductive items include some wall paints and linoleum. So
where is earth ground in this circuit? Not part of the
discharge circuit for static electricity.
Wall receptacle is too far from earth ground to provide
surge protection. This made woefully obvious once one
calculates wire impedances. Also demonstrated by application
notes from 'real world' surge protector manufacturers. This
'no earth ground available' problem is why plug-in protectors
quietly don't even claim to protect from the typically
destructive surge - and yet charge $15 or $50 per protected
appliance.
Even two wire only homes can have effective protection
installed for about $1 per protected appliance. That means a
breaker box earth ground must be upgraded to meet post 1990
NEC requirements AND a 'whole house' protector connects every
incoming AC wire less than 10 feet to that earth ground.
Notice the phrase 'less than 10 feet' - quite significant.
There is no way around this fact. A surge protector is only
as effective as its earth ground. And wall receptacle safety
grounds do not provide an effective earth ground.
For about $1 per protected appliance, this 'whole house'
protector can be installed to provide missing surge
protection. If the earth ground rod (from breaker box) is
installed to meet post 1990 code requirements (and to make
surge protection possible), then a telephone wire 'whole
house' protector (installed free by your telco) and the CATV
wire also must make a 'less than 10 foot' connection to that
same earth ground before entering your building. Just more
simpler solutions to provide effective surge protection for
your computer.
Detailed concepts of household grounding are explained in a
recent post in the newsgroup sci.electronics.misc on 7 Dec
2004 entitled "Does the earth "complete the circuit" to become
ground? " at
http://tinyurl.com/439ff
Your bottom line: Unlike other posts, this one describes
requirements, code upgrades, historical example of failures
and why they happened, technical concepts, and the numerous
types of grounds. IOW some responses only reiterated urban
myths - made obvious by a lack of 'why and how'. It would be
nicer to have three wire receptacles. But posted are less
expensive and more effective solutions to a bad problem - for
both human safety and transistor safety reasons.
Jim wrote:
Hi all, this is my first post on these groups so please be gentle =).
My wife and I have just moved into a rental appartment. I didn't
notice until after we moved that there are no grounded outlets
available. I'm a programmer by trade and I make heavy use of fairly
expensive computer equipment so I was a bit concerned. I informed my
landlord of my concern and he consulted his electritian who suggested
that GFCI receptacles be installed.
Now I've been doing a lot of research the last week on the subject but
it seems to me that using GFCI receptacles does not do much to protect
my computer equipment against surges for the following reasons:
1. Static electricity buildups in the computer has no "outlet" and
can either fry the circuitry or create a shock hazard.
2. This I didn't read from a user group but kind of deduced from
reading descriptions of GFCI receptacles, I may be wrong - A GFCI will
not protect your equipment from a surge simply because it works by
monitoring the difference between the hot and neutral. A surge could
occur, fry your circuitry, then go to your neutral without causing an
imbalance between the two. Any electricians out there please verify
this.
Now I spoke to the electrician and he first told me that I don't need
grounding, just a surge protector. When I informed him that I have
done research and that surge protectors use grounding to work, he
switched his story and said that the GFCI is grounded. The landlord
will only follow the advice of this electrician, who will not advise
otherwise than to use a GFCI.
I've talked to my landlord and he will not install grounding even if
I pay for it. He pretty much told me that I should move out if I
don't like it. That brings me to my question. Is using GFCI instead
of grounding that big of a problem? Am I overreacting? Moving is a
hassle and I don't want to resort to it if i'm just being paranoid.
I live in Hawaii if that helps. I appreciate any help you guys can
give me.