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tzekl · Sep 13, 2007, 08:18 PM

Single power source being run into bathroom.

I wired a standard receptacle in a double gang box. From this I took power for a light fixture (with a separate switch) and a ceiling fan (with a separate switch).

Worked fine without a hitch but I had one white and one black on each side of switch. So I think I have done something backwards. Mind you, everything worked.

This is where the GFI comes in... I wired the GFI exactly as I had the standard receptacle and got the green light on receptacle but no power anywhere. I've tried a few different combinations but nothing works.

KISS · Sep 13, 2007, 08:47 PM

See this:

http://www.passandseymour.com/pdf/U013-U020.pdf

GFI's are wired differently depending if they protect the downstream devices as well.

Flying Blue Eagle · Sep 13, 2007, 10:02 PM

TZEKI, INside the box the gfi recept. Came in is a piece of paper, on it showes hoe to wire a gfi recept. KeepIt simplestupid was right if you didn't get one with the gfi go back to store and get one there's no charge for the instructions

KISS · Sep 13, 2007, 10:16 PM

FBE:

Are you related to Youdee? http://www.udel.edu/PR/UDaily/2004/youdee090203.JPG

Or the Blue hen Delaware State Bird - Blue Hen Chicken

tkrussell · Sep 14, 2007, 02:32 AM

Can you describe what you have in more detail?

You mention standard outlet, then a switch with black and white wires, then a GFI. What exactly do you have and how is it connected?

IS a breaker tripping? Is there another GFI elsewhere in the building that may be tripping?

tzekl · Sep 14, 2007, 05:00 AM

Originally Posted by tkrussell

Can you describe what you have in more detail?

You mention standard outlet, then a switch with black and white wires, then a GFI. What exactly do you have and how is it connected?

IS a breaker tripping? is there another GFI elsewhere in the building that may be tripping?

Breaker is not tripping. What I have is power coming into double gang box where I have GFI and a switch for the fan. Also in the room is a switch for the lights - switch is in a single gang box within 1' of double gang box.

I have one wire running from light to single gang box. I have one wire running from fan to double gang box.

donf · Sep 14, 2007, 08:08 AM

Tzekl,

I am not an electrician, nor do I have the NEC Code book yet, so I would immediately defer to TK's responses. Prior to doing any work on the wiring you need to turn the supply breaker OFF. Working on live wires can get you dead or severly injured. Please don't try to prove how easy it is to kill yourself. Of course if you list me as your only benificary, I might reconsider my prior statement. :)

Before I start making any suggestions I need to know how you wired all switches and outlets.

I am first concerned about the amperage of the source load line (black) at the panel box. If it is 15 Amp and you are using a 20 amp GFCI, you may have to pull a new 20 amp line from the panel box to the bathroom.

In general, (I believe) you should bring your source power to the light box. You would then run what's called a switch loop to the switch and tie the source to the black of the switch loop. At the switch as well as at the ceiling box you place a small amount of electrical tape around the white insulated wire from the switch. You do this so you know that this particular wire is no longer a return wire, it is a Hot or Load wire. Then you connect the white wire with tape on it to the black wire of the light fixture. And the other end of the marked white line to the other end of the switch.

That gets you your first light working. Now, Is everything supposed to work off this one power source? If yes, have you tried to reset the GFCI outlet? Also with a meter or a circuit tester, let verify that you actually have power to the GFCI outlet.

Do you understand how a GFCI Outlet works and what it does? There is a very good book called "Wiring Simplified", put out by Black and Decker, which is available at Lowe's, Home Depot , Barnes and Noble, Borders. This will explain how to plan your new circuit and how to correctly wire the circuit to meet the NEC Code.

A GFCI outlet uses a small chip in the outlet to induce a signal across the return line.
If the signal remains balanced, every thing works fine. However, if the signal changes, and the amperqage climbs, the outlet opens.

The outlet chip is looking for two conditions:

1) Hot Fault - The source power gets crossconnected to a return or ground line or a short exists.

2) Ground Fault - the signal induced across the neutral or ground wire changes because the amperqage of the neutral iws higher than the amperage on the ground side. The amperage I am speaking about is that of the induced signal by the GFCI's chip, not the circuit's amperage.

tkrussell · Sep 14, 2007, 01:59 PM

Donf, can you provide backup to your description of how a GFI works?

KISS · Sep 14, 2007, 02:31 PM

I'll provide a reference to how a GFCI works:

http://cache.national.com/ds/LM/LM1851.pdf

donf's description is not quite right.

tkrussell · Sep 14, 2007, 07:55 PM

Kiss, I agree, but since he made the statements I would assume backup can be provided, as there is so much accurate info available from reliable sources on the net.
This action may give a chance to learn and make necessary corrections.

donf · Sep 15, 2007, 08:00 AM

Originally Posted by tkrussell

Kiss, I agree, but since he made the statements I would assume backup can be provided, as there is so much accurate info available from reliable sources on the net.
This action may give a chance to learn and make necessary corrections.

TK - Kiss,

The source of my description is from the Code Check site. I'll get the actual address later it's on my laptop and I'm now supposed to be cleaning the garage.:D

What I described was the working of a GFCI outlet, not a GFCI Breaker.

What errors did I make do I don't repeat the mistakes? KISS, are you a licensed master electrician? I ask so I know who to accept answers from without question.

Don

tkrussell · Sep 15, 2007, 08:09 AM

All GFI devices monitor the flow of current in both conductors of a circuit and trip if the difference between both are at the setting of the GFI, 5 milliamps for standard products for personnel protection, 30 milliamps for equipment protection, they do not send out a signal.

Jack of all trades, master of one here. Formerly had E1 Master License in two states,only one now, let one go, why spend money each year in a state I am not planning on returning to. Certified Electrical Inspector in that state for life, thou. Go figure.

Flying Blue Eagle · Sep 15, 2007, 06:25 PM

HEY: KEEPITSIMPLESTUPID, NO I am not related to (youdee )or the Blue HEN, DELEWQARE State Bird OR THE BLUE HEN BIRD ARE YOU?? :::

donf · Sep 16, 2007, 06:14 AM

TK - Kiss,

I got the operation of a GFCI outlet off the Code Check site. Here is the link. www.codecheck.com/gfci_principal.htm

Pleased let me know if I misinterpted any thing.

Don

donf · Sep 16, 2007, 06:50 AM

TK,

When you say two conductors are you referring to the Neutral and Ground?

tkrussell · Sep 16, 2007, 07:02 AM

The description states as quoted:

"The GFCI operates by sensing the difference between the currents in the Hot and Neutral conductors.".

No where can I find the words induce a signal across the return line.

Clearly you had misinterpreted the description of how a GFI device operates.

Hope this helps in clearing up this matter.

And yes, the two conductors are the hot and neutral.

donf · Sep 16, 2007, 07:14 PM

To detect a Neutral to Ground fault there is a second transformer (left toroid in the illustration below) placed upstream of the H-G sense transformer (in the illustration above). A small drive signal is injected via the 200 T winding which induces equal voltages on the H and N wires passing through its core.

Inducing voltages in the two lines would change the waveform of the line. The term "Signal" means that the outside signal (voltage) is something that can be read. It's the same principle used in AM radio carrier signals. The carrier wave is generated and the signal is superimposed on the carrier wave.

tkrussell · Sep 17, 2007, 01:27 AM

That signal is internal to the device, it does not leave the device. A signal is not sent out, or "induced" onto the branch circuit conductors.

KISS · Sep 17, 2007, 06:46 AM

My turn:

This is mostly wrong:

A GFCI outlet uses a small chip in the outlet to induce a signal across the return line.
If the signal remains balanced, every thing works fine. However, if the signal changes, and the amperqage climbs, the outlet opens.

The outlet chip is looking for two conditions:

1) Hot Fault - The source power gets crossconnected to a return or ground line or a short exists.

2) Ground Fault - the signal induced across the neutral or ground wire changes because the amperqage of the neutral iws higher than the amperage on the ground side. The amperage I am speaking about is that of the induced signal by the GFCI's chip, not the circuit's amperage.

A GFI outlet will find the following faults:

1) An unintentional current path between L1 and ground determined by the difference in current flowing in the N and L1 leads.
2) A grounded neutral fault.

An outlet generally knows nothing about overloads.

(1) is detected in a very easy way. You wind the current carrying conductors on a small transformer such that their induced flux cancel. You place a sense winding on the same transformer. A measurable signal will result when the currents become unbalanced. It's looking for about 6 mA.

2) is detected a little harder. L1 and N are wound on a core, but this time a 120 Hz signal is induced in L1 and N such that the signal would normally cancel and the load would not see it. If N of the load is connected to ground, it becomes impossible to modulate what would normally be N. If this modulation occurs before the transformer designed to detect (1), the modulation can be seen on it's sense leads too. The modulation on L1 would be seen for as long as it took the GFI receptacle to respond.

KISS · Sep 17, 2007, 07:17 AM

A little about me: AAS in Electronics Technology 4.0 GPA. BAS in Engineering technology, 2 YRS of work in an EE degree. I built a computer out of small scale integration around the time the 4004 came out (Think the Texas Instruments SR10 calculator era). It could sort numbers in ascending and descending order depending on the microcode.

My strengths are in Electronics instrumentation and electrical measurements of semiconductors, Mechanical design and construction and computer programming skills. I also posses machine shop skills. I've even designed instrumentation from scratch. Semiconductor measurements can involve currents as low as 1E-12 Amps (1 picoamp) at 100 volts DC.

I'm capable of working on X-ray sets with 100 KV, 0.1 A power supples, Electron Beam systems with 15 KV at 2A (30 KW) power supplies and 1KW Tube RF generators without killing myself so a wimpy thing like a micowave doesn't bother me either.

I've worked on TV's, Radios, both tube and transitor before age 15. At 15, I removed the heads from my car, upolstered the seats, ported the intake manifold, rebuilt the carb, retro-fitted electronic ignition and got 18 mpg on a 6 cyl 1965 ford. Not bad for that time frame. I rebuilt lawn mower engines when I was 12.

I'm not your ordinary "Saturday mechanic", since I've rebuilt carbs with 120+ parts, installed an AC from a box (I'm Automobile/small appliance certified), replaced clutches, and wheel bearings. I've generally stopped working on cars for now to concentrate on other issues.

Plumbing and pointing a chimney to name a few.

My designs and fixes generally last a long time. I'm a conceptual person. Mostly self-taught. I can read.