Shared Knowledge
“Converting a 2 Prong Electric Outlet
to a Newer Type 2 Prong and Ground Outlet”
Recently, helping a neighborhood
lady prepare her home for the real estate market,
discovered that in her basement, she had 7 of the old 2 prong outlets. You know
the type you have to use an adapter for to plug in just about any modern
appliance or tool.
The following is what I did
to replace the old 2 prong with a new 2 prong and ground outlet:
-
Bought a 3 prong
outlet tester. Available at any decent hardware store, when plugged into a 3
prong outlet, this handy tool confirms that the power prongs are not miss-wired
and that a ground is actually present on the ground prong of the outlet. It is
this device that any home inspector will use to test outlets when he does a
home inspection for a home buyer.
-
Shut down power
to the whole house. As is the case in many older homes where electric cabling
and even the circuit breaker panel has been modified, perhaps several times, I
just shut down power to the whole house to get some level of comfort that the
outlet I am going to work on is actually electrically dead.
-
At the outlet to
be replaced with a new 2 prong and ground outlet, I unscrew the outlet cover
and then the outlet itself. In many older homes, a metal box was used to house
electrical outlets and thus not being 100% sure that the outlet is electrically
dead, I carefully pull the outlet out of the box so that its terminals do not
accidently touch the metal sides of the box and use a volt meter to confirm
there is no power to the outlet. Believe it or not, I have come across wiring
that was tied directly to house service and not through a circuit breaker or
fuse box or panel.
-
What I have found
in all cases so far is that when electrical cable was run and the metal outlet
box installed, the ground in the cable was tied to the box, perhaps on the
outside of the box making it difficult to see but because the box was grounded,
the tabs on the outlet were supposed to make contact with the metal box to pick
up the ground. Problem is, over time, wall covering materials change and
eventually, the outlet no longer actually touches the metal box or only
slightly through the screws holding the outlet into the box. Or the metal box
becomes coated in paint and the outlet tabs never touch the bare metal of the
surrounding box. So in each and every case, to be sure, I attached a piece of
ground wire to the box and ran it directly to the ground lug of the new outlet.
Although a hassle, this absolutely ensures that the ground prong of the new
outlet is, in fact, connected to ground.
-
I then connect
the black and white wires on the correct sides of the outlet as defined by the
outlet itself and secure the outlet back into the metal box.
-
I then apply main
power to the house and check the newly installed 2 prong and one ground prong
outlet by using my outlet checking tool. Everything must be correct: polarity
as well as ground present. Once I have confirmed the outlet is wired correctly,
I place the outlet plate back over the outlet and screw it into position.
Certainly
not difficult to do. The main
things of importance defined include: (1) trust not nothing.
House wiring can get really balled up overtime and although not likely, an
outlet could be electrically hot even with all power turned off to the house
and (2) In all likelihood, a ground is present at the metal box although you
might not see a ground wire inside the box and (3) I feel most comfort affixing
a wire to the box and running it directly to the ground lug on the outlet
rather than relying on the metal tabs of the outlet making ground contact with
the metal outlet box.