[PLUG-TALK] Electrical circuit branch: identify first outlet

[Denis Heidtmann]

Only two wires (one cable) means that it is the last. All the others will
have two cables.  This assumes they are in a single line; no branching.
(Branching would require three cables in one outlet.) On that assumption,
choose the outlet you guess is most likely the first and disconnect one
black wire. Does that cut power to all the other receptacles? If so, you
have found the first and you are ready to put in the GFCI.  If not, make
another guess among the outlets which remained powered and repeat.

When you have found the first, you have to determine which cable comes from
the panel. Use your tester to determine that. That cable will connect to
the power into the GFCI. The other cable will connect to the LOAD terminals.

BTW, to be precise, "outlet" is the box into which the cables are routed.
"Receptacle" the thing that you stick the plugs into.

Be safe and careful.

-Denis

On Tue, Jan 3, 2023 at 3:07 PM Rich Shepard <rshepard at appl-ecosys.com>
wrote:

> I've learned that I need a GFCI outlet on only the first outlet in a
> circuit
> branch, not all of them. Now I need to learn how to identify the first
> outlet in a branch, initially the branch marked in the service box as
> 'bedrooms/baths'.
>
> My initial research suggests I pick a room (perhaps the bedroom on the same
> side of the house as the service box in the garage) and, after turning off
> the circuit breaker for that branch, remove the outlet cover, test the
> circuit's not live, then remove the outlet and look at the wires connected
> to it.
>
> Two wires alone (black and white) means it's not the first one. Put back
> everything, go to next outlet, rinse, repeat. Find the outlet with black
> and
> white wires on both the line and load ends of the case.
>
> Is there a better way of doing this? I have a circuit testing tool odered,
> but I don't know that I can use that to indentify a circuit branch's wiring
> sequence.
>
> Rich
>
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