Finding first 120v receptacle in circuit?

Any easier way to determine which is the first receptacle in a series of 4 besides opening one up and loosing the wiring to see what happens with the others? Tried tracing the wires and they go down into never never land and can't see where they go. Looking to add GFCI and my understanding is that they need to be the first in the circuit (despite a "Marine Electrician" telling me they can go anywhere in the circuit).

I don't know of any easier way than loosing a wire and see which ones aren't hot anymore. And it is often difficult to tell which one is the supply and load side of the connections so you have to measure for voltage once you disconnect.


You are correct, the GFCI only protects the circuits downstream of it

David

firstbase said:

Any easier way to determine which is the first receptacle in a series of 4 besides opening one up and loosing the wiring to see what happens with the others? Tried tracing the wires and they go down into never never land and can't see where they go. Looking to add GFCI and my understanding is that they need to be the first in the circuit (despite a "Marine Electrician" telling me they can go anywhere in the circuit).

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Its easy. Plug in a high load device, like a space heater. Take a DMM on AC range and look for the highest V recept. That is #1.. in order of V to last.

Thanks guys. Just got lucky by taking out the one I suspected was first on one circuit and was correct. On to my next issue which is the receptacle is on the back of the lower helm seat. Not deep enough for the larger GFCI. Receptacle is tucked in the corner out of the way so it seems like my best choice would be a teak spacer to give me more depth. don't need too much. Back home to the table saw. Will check the second circuit first to make sure I don't need two spacers. Wow. I actually thought ahead. Never happens to me on the boat.

If you ever wanted an excuse to buy a 3D printer. You have it now.

Put GFI in the electrical Panel, all down stream are protected.

Ejdakins said:

Put GFI in the electrical Panel, all down stream are protected.

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OK, time out. Do you mean a GFI breaker on the panel? If so then maybe it is already installed? How would I check? They would look different than a regular breaker? Backing up even more, how do you check to see if GFI is installed in a circuit to begin with?

tiltrider1 said:

If you ever wanted an excuse to buy a 3D printer. You have it now.

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Hopefully my son doesn't read this as he wants one so bad it hurts as they say.

firstbase said:

OK, time out. Do you mean a GFI breaker on the panel? If so then maybe it is already installed? How would I check? They would look different than a regular breaker? Backing up even more, how do you check to see if GFI is installed in a circuit to begin with?

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1) Look for a Push To Test button. or 2) Buy a GFCI circuit tester at Amazon. $5.00 or 3) fill up your sink and drop your toaster into it.

SoWhat said:

1) Look for a Push To Test button. or 2) Buy a GFCI circuit tester at Amazon. $5.00 or 3) fill up your sink and drop your toaster into it.

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1) I'm talking about on the panel. Would a breaker on the panel have the test function like a GFCI receptacle? 2) GFCI circuit tester. Huh. Go figure. Didn't realize those tested for GFCI as well as simple power/ground. 3) Don't keep a toaster on the boat. Would a heat gun work?

As an electrician I make a good pastry chef.

firstbase said:

1) I'm talking about on the panel. Would a breaker on the panel have the test function like a GFCI receptacle? 2) GFCI circuit tester. Huh. Go figure. Didn't realize those tested for GFCI as well as simple power/ground. 3) Don't keep a toaster on the boat. Would a heat gun work?
As an electrician I make a good pastry chef.

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All GFCI/AFCI breakers have test/reset button.
Heat gun would be fine. (Stick to baking.)

Note that you could add another outlet and make it the first one in the circuit with a little rewiring. Panel update is first choice if you have good access to buses behind the panel. If wiring is a spaghetti nest then I might opt for new outlet.