modified GFCI

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JR.
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Re: modified GFCI

Post by JR. » Tue Sep 01, 2015 9:55 am

Speedskater wrote:There are dual GFCI receptacles available with a low form factor. Designed to fit in older outlet boxes.
I bought the cheapest GFCI outlet 3=pack made in china... I still plan to put the third on my washing machine/dishwasher outlet that is about 6' from my panel so I will probably grab an actual ground making that my only grounded outlet in my whole house. Perhaps before I do that I will check the width of that junction box too,,, :lol:

thanx

JR

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JR.
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Re: modified GFCI

Post by JR. » Thu Sep 10, 2015 10:22 am

I just ordered my 2nd generation outlet tester PCB...

I fixed one weakness.. The first generation would sometimes give a false ground present indication.

So now it appears solid based on my testing. Same sized PCB but a full house with even more parts.

I added another Power present LED(s) so you can tell if outlet is energized without touching it (useful for trying to cut off power for outlet servicing. I also added some shunt resistors to reduce ghosting from leakage. I moved the LEDs down to the edge of the PCB so they can be seen through the line cord hole. My clear plug was hard to see through (and expensive).
out_test_2.jpg
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I ordered proto PCB from China again $14. (DirtyPCB). This time I paid up for delivery from Singapore ($9 extra). Still quoting 8 weeks worst case. We'll see if the extra $9 buys me faster delivery. Last time free shipping from Hong Kong took 3 weeks. I just can't stomach paying $33 for DHL shipping on $14 order

JR

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Re: modified GFCI

Post by Speedskater » Thu Sep 17, 2015 8:00 am

After hunting about I did find the smaller Leviton GFCI's for old work.

SmartlockPro® Slim Series GFCIs Install in Any Electrical Box
When it comes to GFCI installation, size really does matter. That's why we've trimmed the profile of our industry-leading SmartlockPro GFCI receptacle to fit into any wallbox, even shallow ones.

http://www.leviton.com/OA_HTML/SectionD ... site=10251
Kevin

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JR.
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Re: modified GFCI

Post by JR. » Thu Sep 17, 2015 9:14 am

Thanx.. I bought a replacement junction box (plastic) but I am reluctant to mess with it again while it is working and not shorting out to the metal junction box now.
=====
My new circuit boards have shipped from singapore. Lets see how many weeks that takes.

JR

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JR.
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Re: modified GFCI

Post by JR. » Wed Oct 07, 2015 12:35 pm

P1010122.JPG
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Still takes about 3 weeks to get PCB from singapore ($9 more than hong kong).

Picture shows cheap commercial outlet tester saying that an intentionally miswired (RPBG) outlet measures good... (dangerous 120VAC on safety ground).

My tester in the bottom plug, correctly indicates the dangerous situation when I touch the probe.

JR

PS: 32 SMD components on that tiny PCB, I'm too old for this sh___ :lol:

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mediatechnology
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Re: modified GFCI

Post by mediatechnology » Wed Oct 07, 2015 1:13 pm

Very cool!

The probe is a touch plate?
Did you "borrow" a plastic case from a USB charger or did you 3D print one for your "plug?"

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JR.
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Re: modified GFCI

Post by JR. » Wed Oct 07, 2015 4:24 pm

mediatechnology wrote:Very cool!

The probe is a touch plate?
The probe is a bare wire, that I fed out the same hole as one of the two screws that hold it together. I wrap the wire under the screw head and over to the other screw and back again.

This is just a prototype- proof of concept, The production version can use some conductive rubber or maybe even conductive paint. My probe contact has 1M in series, so can be pretty high impedance.
Did you "borrow" a plastic case from a USB charger or did you 3D print one for your "plug?"
Actually that is an off the shelf replacement plug. I removed some plastic inserts from the end, but the circuit board fits entirely inside that stock plug housing.

The company I am trying to get to make these with me, has some funny plugs tooled up and in their product line.
So I could fit several of mine inside that plug housing... (or one with proper UL spacing) :lol: .

I would really love to hand this off for them to finish... I did the hard part. But this still need UL approval, yadda yadda,,,

JR

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JR.
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Re: modified GFCI

Post by JR. » Sun Nov 01, 2015 1:09 pm

Prototype2 wrote:Come to think of it, won't the configuration mean that even without the blue LED there will always be two other LEDs lit? Doesn't that on its own serve as "power present" indication? "Less is more" and all that...
No.... Just to reiterate how my tester works. The blue power present and green ground Ok (when ground path is actually present) are always lit. However if there is no ground, (like most of my house) only the blue lights up. In fact my neighbors outlets I tested last week, 2 out of 3 had open grounds.

The the red, yellow, and green LEDs are only lit when touching the reference probe. If trying to identify which fuse/breaker to open from any distance, so you can repair an outlet, I think the blue LED is OK, but I am not married to blue. In fact it makes the green harder to read.

JR

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JR.
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Re: modified GFCI

Post by JR. » Sun Nov 01, 2015 3:39 pm

OK update for my outlet tester...

At AES show in NYC this week, a friend put a picture of my tester in his power point demo at a panel discussion he gave about grounding and power safety. After his discussion several people asked him where they could buy one.... Hmmmm. :D

The company I am trying to get interested does not seem very interested... so for now I am moving on by myself.

I ordered the UL spec for outlet testers and for $400 it is pretty interesting... I have a few problems with it, but now that paid my dues maybe I can ask them questions (and get answers).

Well see, I do not expect UL approval to be cheap or easy. .

JR

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Re: modified GFCI

Post by Prototype2 » Sun Nov 01, 2015 5:35 pm

JR. wrote:if there is no ground, (like most of my house) only the blue lights up
Ah, I see, fair enough! Though with the risk of being annoying, shouldn't missing ground be regarded as a fail/warn condition? At least here in Europe it is a legal requirement that all outlets provide an earth connection - though in my previous office I found a row of sockets that had an earth wire connecting only the sockets, ending at the last socket with no actual connection to ground (or even neutral). So a device plugged into any of the sockets which had a fault leading to a hot ground could potentially energise the housing of all other earthed devices connected to that row of sockets - actually worse than having no ground wire at all!

I wouldn't mind blue LEDs so much if they were actually a deep, saturated blue, similar to how other LEDs are, but they always seem to be far too bright and washed out looking, often with a narrow beam, and tend to dominate over other indicators. I find them distracting and annoying and usually I'll either replace them with a diffused LED of a different colour (with an appropriate series resistor) or simply cover them up with some black electrical tape :)
Last edited by Prototype2 on Sun Nov 01, 2015 5:42 pm, edited 1 time in total.

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