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Author Topic: brain storm an optimal human safety system for back line  (Read 186292 times)

Stephen Swaffer

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Re: brain storm an optimal human safety system for back line
« Reply #450 on: February 18, 2016, 02:22:49 PM »

I would let it trip it and not worry too much about it.  I am thinking that a RPBG GFCI would trip nearly anytime anything was plugged into it, so I doubt they would remain in the wild for any length of time.
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #451 on: February 18, 2016, 03:34:25 PM »

I would let it trip it and not worry too much about it.  I am thinking that a RPBG GFCI would trip nearly anytime anything was plugged into it, so I doubt they would remain in the wild for any length of time.

If they bootleg the ground to the output side of the GFCI at least that path will be inside the loop and not trip the GFCI, while any current leaking to the outside world will trip.

I will register your vote for trip...

JR
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Jonathan Johnson

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Re: brain storm an optimal human safety system for back line
« Reply #452 on: February 18, 2016, 04:50:32 PM »

How does your tester respond to a proper-polarity bootleg ground (ground screw jumpered to neutral screw; neutral screw actually wired to neutral)? Is it happy as a clam?

I can't remember if this was discussed, and I don't want to wade through 400+ posts.
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #453 on: February 18, 2016, 06:08:39 PM »

How does your tester respond to a proper-polarity bootleg ground (ground screw jumpered to neutral screw; neutral screw actually wired to neutral)? Is it happy as a clam?

I can't remember if this was discussed, and I don't want to wade through 400+ posts.
Yes it registers exactly the same as a true ground.

It even reports the RPBG ground as a valid connection, but it also registers that neutral and ground are energized. If the red LED says the ground is hot, ignore the green LED saying that a ground path is present.  8)

JR
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Jonathan Johnson

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Re: brain storm an optimal human safety system for back line
« Reply #454 on: February 18, 2016, 08:00:55 PM »

Yes it registers exactly the same as a true ground.

It even reports the RPBG ground as a valid connection, but it also registers that neutral and ground are energized. If the red LED says the ground is hot, ignore the green LED saying that a ground path is present.  8)

JR

Aha! So it CAN be fooled! Charlatan!!!  :o ??? ::) 8)
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #455 on: February 18, 2016, 08:19:30 PM »

Aha! So it CAN be fooled! Charlatan!!!  :o ??? ::) 8)
If you ignore the bright red LED warning you.....  :o

A ground being connected is not as important as it being 120V!

JR
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #456 on: March 17, 2016, 01:11:53 PM »

Since the last cut OD-1 PCB is already obsolete due to further refinements ( a problem with slow shipping and fast tweaks). I decided to wail until it arrives, to confirm that my chinese PCB fab got the holes right this time (last ones were too small.) Since these boards are coming slow boat they still haven't arrived (already 3+ weeks since they left hong kong). I expect them any day.

As I refine the design for cost and UL acceptance, I feel like I am very close. In a strange pricing quirk, I can buy a 1W 100M resistor rated for 600V for $0.14, while the more sensible 1/4W resistor is $0.75 in quantity.  ::)

Note: the huge 1W resistor just above the center hole in the PCB layout, I placed a 1/4W resistor on top of it, so I can use either in the final build, should I find a more sensibly priced 1/4W resistor later.

I struck out with the second company that I was trying to partner with (maybe it's me?  >:(

I have prepared a web page to better tell the OD-1 story  http://circularscience.com/home/terms-and-conditions/od-1  Please feel free to share my webpage with anyone you think might be interested. I need to cast a wider net, or I will literally have to manufacture these myself.

JR

 
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #457 on: March 19, 2016, 12:28:09 PM »

The good news is that the previous (already obsolete) cut of PCB arrived this morning and the holes are the right size...so no more excuses... I will probably spend the weekend checking for spacing and layout tweaks.. before releasing the LAST FINAL PCB DESIGN.

UL has rules for spacing between line or neutral conductors and conductive metal, but I will even try to maintain that UL spacing to any exposed solder contacts. The only exposed piece of metal in my tester has an 100M resistor in series. 

I don't think I'll wait for slow boat delivery this time, that was like 3 1/2 weeks.. It will double the cost of the PCBs but time is money and I'm getting impatient (old).

Regarding final feature set:

*It will NOT trip GFCI outlets. The UL spec stipulates <2mA ground current, so less than the 5mA trip leakage.

*The ground present LED only indicates that a ground path is present (or not), not the quality of that ground.

*It will detect line-neutral reversed and hot safety ground situations (like RPBG).

JR

PS: please share this link with anyone you know who does electrical work http://circularscience.com/home/terms-and-conditions/od-1 You don't want to make me build these...

 
 
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frank kayser

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Re: brain storm an optimal human safety system for back line
« Reply #458 on: March 20, 2016, 12:11:40 PM »

PS: please share this link with anyone you know who does electrical work http://circularscience.com/home/terms-and-conditions/od-1 You don't want to make me build these...


I think you had mentioned that offering them as a kit is just not feasible - due to your past experience with offering kits, UL rating, and the inability of most mortals to not be able to solder/work with SMD components.   Do I have that basically correct?


Here's hoping you find someone!


frank
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John Roberts {JR}

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Re: brain storm an optimal human safety system for back line
« Reply #459 on: March 20, 2016, 12:21:54 PM »


I think you had mentioned that offering them as a kit is just not feasible - due to your past experience with offering kits, UL rating, and the inability of most mortals to not be able to solder/work with SMD components.   Do I have that basically correct?
Since I have been hand assembling these prototypes myself,,, I can assure you these would not make a good kit product. Not only would I be uncomfortable about exposing consumers to hazards from incorrect assembly, UL not only certifies the design, but that the factory building them will follow that design and only use the specified components.

UL was a regular visitor to the Peavey factories to check our work. 
Quote

Here's hoping you find someone!


frank
Thanks... me too...

JR
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Re: brain storm an optimal human safety system for back line
« Reply #459 on: March 20, 2016, 12:21:54 PM »


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