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Suretests and GFCI's


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I've been using my shiny little Suretest for a couple of weeks now and I notice that most GFCI's I test will trip at 7.3 or 7.6mA. I've read that some really Pecky inspectors consider this a serious life safety hazard because GFCI's should trip at a fault between 4-6 mA. I have a hard time swallowing that, but still wonder about the disparity. How many milliamps are too many?

Douglas, Keeper of the Knowledge of All Things Electrical, can you point me toward enlightenment?

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Originally posted by Jim Morrison

I've been using my shiny little Suretest for a couple of weeks now and I notice that most GFCI's I test will trip at 7.3 or 7.6mA. I've read that some really Pecky inspectors consider this a serious life safety hazard because GFCI's should trip at a fault between 4-6 mA. I have a hard time swallowing that, but still wonder about the disparity. How many milliamps are too many?

Douglas, Keeper of the Knowledge of All Things Electrical, can you point me toward enlightenment?

Jim,

Toss that tester away. Try a more reliable method like I do. Fill the sink with water. Plug in the hair dryer, turn it on, hand it to the agent and ask him/her to see if it works under the water.

Dennis

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Hmmmmmmm. Two birds, one stone. Well, just to satisfy the curiousity of my egg-shaped head I'll wait for Douglas' response before making any irreversible decisions.

BTW You should be more careful with what you post here. People who don't know you might misunderstand and get the idea that you have a problem with real estate agents.

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Okay Guys,

Let's not turn Jim's question into another realtor sniping session. That kind of stuff has no place on the Electrical forum. And, if you expect Douglas, as moderator of this forum to answer this, you need to understand that he hasn't got a whole lot of patience with folks carping about stuff, instead of presenting solutions. When you interject that kind of stuff into a thread, he tends to not answer. When it becomes indemic, he has a habit of going away and not coming back for a loooonnnnng time. I think that would be a disservice to everyone here. That's a hint.

Jim, according to Douglas' book, "(snip)The UL Standard today says that a Class A GFCI must trip when an imbalance of 6 milliamps exists, and the GFCI must allow an imbalance of 3 milliamps without tripping.(Snip)Class A GFCI's are designed to protect people from shock hazards. Class B GFCI's, with a higher trip threshold, are for swimming poollights that predate the grounding requirements of the 1965 NEC®."

ONE TEAM - ONE FIGHT!!!

Mike

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I hope you guys don't kick me out of the club for this, but I was curious, so.....I read the directions. I know, I know....

If you have the new Ideal 61-155 like me, they read: " To activate the GFCI test, press the GFCI button...The actual current being bled from hot to neutral will be displayed. (6mA is the nominal current sent through the fixed resistor....)"

Like I said before most every GFCI i've tested in the past few weeks trips at either 7.3 or 7.6 mA. So I guess the engineers at either Ideal or Leviton are due a kick in the pants.

But my question is:

Is the extra milliamp and a half actually meaningful in the real world, or am I just trying to pick fly shit out of black pepper?

What do some of you veteran Suretesters say about this, if anything?

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Jim,

I'd just like to provide some information that may help add perspective:

1 mA - Barely perceptible

16 mA - Maximum current an average man can grasp & "let go"

20 mA - Paralysis of respiratory muscles

100 mA - Ventricular fibrillation threshold

2 Amps - Cardiac standstill & internal organ damage

15/20 Amps - Common breaker opens circuit

Since GFCI's are designed for personnel safety & contact with 20 mA of current can be fatal, a 25% delay in device operation may be substantial.

Just adding to the fire.

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Originally posted by Douglas Hansen

. . . For instance, I try to read a message from Jim Morrison, and half way through, Calvin's head explodes. All that does is prevent me from reading what Jim said.

. . . And FWIW, Dennis suggestion did get a good guffaw out of me - the image of the realtor holding the dryer brought tears to my eyes, and I need to have a good laugh every day. Thanks.

Perhaps it would help if you envisioned Calvin as a realtor.

- Jim Katen, Oregon

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Originally posted by Douglas Hansen

. . . I think that Jim "Dr. Science" Katen should make us a fancy machine to test the effects of current on the body. . .

I've already got one. My dad's c. 1960s Black & Decker drill with a fault to the case. If you want to feel a little current, it's just the ticket.

On a related note, when I was a kid, my neighbors had a refrigerator with a live case. It gave a nasty bite every time you'd touch it. Being the thrifty New Englanders that they were, they solved the problem by installing a nice thick (used) throw rug right in front of the fridge door. It worked great, no more shocks.

The interesting part though, was the family dog. He liked getting shocked. (In a kinky sort of way.) He'd lie on the floor to one side of the rug and reach his paws out to touch the fridge. Then he'd just lie there with his eyes rolled back inside his head.

As kids, we thought it was hysterical.

- Jim in Oregon

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Douglas and all interested in purchasing Earl Roberts book:

The phone #860-536-4496 will get you a message machine that directs you to call a disconnected phone #530-742-9870. Damn.

The second phone #(860) 442-8424 is a copy center---> think Small Kinkos.

Contacting the author Earl Robers directly is the only way to purchase the book that I have found so far. The manager of the copy center was unable to give me Earl Roberts phone # in Arizona when I called. He suggested I call back later in the week. (?) Perhaps he'll look it up in the meantime. If/when

I am able to purchase a copy of his book I'll post the $ info. and phone #s.

Ron

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Douglas,

It seem that there are 2 versions (1 revision) of this book;

One published 1996 that contains information on GFCIs,

The second published in 2000 and contains information on GFCIs and AFCIs.

I almost bought the wrong one! Woops!

P.S. not from the website you gave us. Thanks

Ron

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Master Hansen,

My search for the truth has yielded more questions than answers, I'm afraid.

Marcy, from Ideal Industries Tech Support, tells me that GFCI's are supposed to trip at ground faults between 6 and 9 mA after 200 milliiseconds . She assures me that the new Suretest ramps the fault up from zero and mine is working fine.

What do you make of her assertion that GFCI's are supposed to trip in the 6-9 mA range?

Has the standard changed?

Yours in the quest for enlightenment,

Simple Jim

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I just recieved my new toy, the Ideal AFCI-155.

While learning how to use it I tested 4 GFCIs at my own house, here are the results:

Line Voltage @ 124V

#1 GFCI tripped @ 7.7 mA and 123mS

#2 GFCI tripped @ 7.7 mA and 124mS

#3 GFCI tripped @ 7.7 mA and 107mS

#4 GFCI tripped @ 7.7 mA and 264mS

(#4 is over the 200mS time slot)

The 2002 NEC (210.8 Article 100)states that a Class A GFCI must trip when the current to ground is between 4mA - 6mA.

My results seem to match the others on this thread, tripping @ >7mA, do we have a conclusive answer yet as to why the 155's read overcurrent?

If I missed the boat and we have an answer to this, please point me in the right direction.

In the meantime I'm calling Ideal too.

Thanks

Ron

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I have the Answer.

I called the main office for Ideal industries today to ask why our #155 analyzers are tripping GFCIs at such seemingly high milliamperage range. No one there could answer my question or wanted to give me a B.S. answer.(thank goodness)I was given the phone number of the West Coast technical rep. so I left him a message.

He called me back!!!! I explained what our concerns were and related the mA range inwhich our analyzers were showing the GFCIs tripped. He (Dave Kadonoff) stated that the (high)#s are due to the variances in line voltage, and the total amount of current changes due to the fixed resistor as the nominal test voltage varies. Uh..Huh? As he explained it the fixed resistor is sized to the lowest voltage we may possibly encounter and therfore skews the upper readings to what we are seeing.

I think I got that right.

Douglas, if this sounds incorrect Please PM me and I will provide you with his cell phone # so you can interpret for us laypeople. (he asked me not to give it out over the net) (sorry)

I hope I helped,

Ron

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