According to the NEC section 210.52 it's not 48" it is 66" (5-1/2 ft.). All
outlets within the 12 ft. maximum spacing code must also be below this 66"
mark to be considered part of the standard spacing in a dwelling unit.
What kind of room are you doing this work in?
For a garage the only outlet requirement is that any duplex receptacles
under the 66" have to be GFI protected. Other than that, you're free to
install as many or few as you wish, spaced out to your liking.
I looked up the code change proposals. The arguments included:
"The permitted leakage current for typical cord and plug connected
equipment is 0.5 ma. The trip range for GFCI protective devices is 4-6
ma. For this utilization equipment to trip the GFCI device, it would
have 8 to 12 times the leakage current permitted by the product standard."
[Applies to both commercial and residential refrigerators - if a
refrigerator trips a GFCI there is something wrong with it.]
"The present generation of GFCI devices do not have the problems of
'nuisance tripping' that plagued the earlier devices."
The thing at used to irritate the heck out of me during the early years of
GFIs was those GFI outlets that tripped when power is first applied to them.
Every time someone had a power failure, all of their GFIs would trip when
power was restored.
Not so dumb.
In older "frostless" fridges sometimes there was a leakage path caused by
the water which dripped down after being melted by the defrost heater.
This, sometimes, could cause a "false trip" on a GFCI protected outlet.
From my experience, "fridges" made in the last 20 years protect the heater
wiring from the water/ice.
There seems to be some "Old Wives Tales" about false tripping.
I don't have any citations to support my views but I just don't believe that
dishwasher, washing machiens, or fridges should "trip" a GFCI. If they do
perhaps they should be checked out.
LARGE numbers of electronic items (including uWave ovens) might cause a trip
because they often have a "network" which connects neutral & hot with the
protective ground. This network is usually just a cap and resister in
If you get enough of these "networks" on one circuit you might trip a GFCI.
My mom has a GE microwave that would trip a GFCI whenever the door was
open right from the time it was new. I looked into it at one point, over
a decade ago, and I recall my conclusion was it was a combination of
bypass capacitors in the RFI filter and the door interlock switches.
Well, here in EU (Greece) there are no GFCI outlets, but only GFCI breakers,
and they protect a whole residence! So, if you have a nuisance trip, you
have to find which circuit breaker isolates the faulty line, and turn it
off. The solution in modern construction is to piggytail almost every
receptacle, and divide each room into 2 lighting circuits, so chances are
slim that a nuisance trip will leave half the house in darkness. Here,
outlets come only in 2 flavors, 10 A (1,5 mm^2-#18)and 16 A (2,5 mm^2-#16).
The receptacles are absolutely the same, only the cable gauge changes. They
(the 16 A ones)are used in washing machines, cloth dryers and dishwashers
and space heaters. Modern residences now have 3 phase, 400/230 V with large
loads being 3 phase and the rest distributed evenly on circuit breakers.
major in electrical engineering
The 2008 NEC removed virtually all the exceptions that allowed a
non-GFCI receptacle where a GFCI receptacle was otherwise required
(including sump pump and refrigeration). (And a separate circuit does
not help.) Stated logic is in a post to krw.
(You can use a non-GFCI receptacle in a kitchen if it is not a
"countertop" receptacle - as before.)
That "makes sense" to me.
If a sump pump trips a GFCI then there is something wrong with the sump
Most folks who rely upon a sump pump have a battery power backup and an
alarm circuit. The backup doesn't kick in until the water is about 6"
above the normal max level.
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