Remember that a UL label does not ensure safety

[don_resqcapt19]

Bill,
Yes, it is UL 943, and the information I posted comes from 6.7.1.1 of that standard. I do not have a complete copy of the standard so, maybe there is something somewhere else in the standard that says 25ms.
Don

 

[wptski]

Bill,
Yes, it is UL 943, and the information I posted comes from 6.7.1.1 of that standard. I do not have a complete copy of the standard so, maybe there is something somewhere else in the standard that says 25ms.
Don

Don:

Here's one I just found that mentions the Ul standard of 25ms: http://www.trci.net/products/hd_pro/faq.html#2. There are several Q&A's, it's in one of them.

 

[jim dungar]

Don,

I think the formula you cited is for when the fault current is greater than the design trip level of 4-6mA for a class A device.

 

[don_resqcapt19]

Jim,
The section says it is for currents in the range of a minimum of 6 mA through a maximum of (110% of rated V/500 ) mA.
Don

 

[don_resqcapt19]

I wonder if the 25 ms is the operation time of the internal relay after it has been told to release? I looked at a number of relay data sheets and find release times of 15 to 30 ms for 2 pole 20 amp relays.
Don

 

[jim dungar]

Jim,
The section says it is for currents in the range of a minimum of 6 mA through a maximum of (110% of rated V/500 ) mA.
Don

That is what I thought, I don't remember what the maximum operating time is at 5mA.

 

[wptski]

I'm still seeing 25ms max or nominal trip time mentioned on a Google search but UL 948 is mentioned for receptacles with UL 817 mentioned also. I don't have a copy of the UL standards just the general info found on-line.

 

[ELA]

The trip time does vary with fault current and the 25ms apparently comes from a particular level of fault current. Unfortunately I do not have access to UL943 to be specific.

Here is a good in-depth link explaining the operation of an IC used inside of a typical GFCI.

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

The graph on page 4 shows how the trip time varies with fault current.
They also talk here about making a compromise between a faster trip time and more noise immunity.

Heres another link where they imply the fault level is >250ma to meet the 25ms req.

http://www.bender.org/Lifeguard GFCI 100A Datasheet.pdf

 

[wptski]

The Ideal Suretest shows the current level first before the test starts. It always around 7.5ma.

Just for comparison if have use of a loaner Fluke 1653 multi-function installation tester not sold in US, used in the UK, etc. on RCD's which are bit different. You can set the trip curent at 10, 30, 100, etc. with 1A being the max I think.

The GFCI's that read 28ms on the Suretest read 3ms of the Fluke set to 10ma. The Leviton's read 66ms. At 30ma on the Fluke, the Leviton's trip at 0ms!

Maybe the minimum trip current is 4-6ma and the maximum trip time is 25ms but not at 4-6ma? As mentioned by ELA above, graphs imply that. Even then this Leviton is way slower to trip than others I've tested! Hey, what would you want installed in your home?

This has been dicusssed here before. The UL standard and I forget the number for a GFCI tester is allowed up to 9ma if I remember correctly.

EDIT: Just received email from Leviton that my question about long trip time has been passed on to the product line manager.

 

[don_resqcapt19]

ELA,

Heres another link where they imply the fault level is >250ma to meet the 25ms req.

And if you look at the graph of the trip time shown in your link for a 6mA ground fault, you will find a maximum permitted trip time of 5600ms...that is what you get using the formula that I posted for a 6mA fault (actually I get 5593.9ms using the formula)
Don

 

[wptski]

ELA,

And if you look at the graph of the trip time shown in your link for a 6mA ground fault, you will find a maximum permitted trip time of 5600ms...that is what you get using the formula that I posted for a 6mA fault (actually I get 5593.9ms using the formula)
Don

Don:

If 5.6 seconds is within UL standards, is this what you'd like to see or does 25ms seem better?? What would you want to use in your own home, one that trips in 25ms or 5600ms?

EDIT: The second link provided by ELA clearly shows as Don stated, UL 943 allows 5600ms at 6ma but the question still remains as to why "other" brands are testing far below that at around 30ms? Either the testee(me), tester or tested is defective!

 

[iwire]

If 5.6 seconds is within UL standards, is this what you'd like to see or does 25ms seem better?? What would you want to use in your own home, one that trips in 25ms or 5600ms?

If 25 ms for all fault levels meant the thing would be tripping frequently due to 'noise' I would want the variable trip time unit.

If they make GFCIs unusable they will not be any help at all.


As far as I am concerned if I install a GFCI and opens when I push the TEST button included on the GFCI I have a working GFCI and move on, be it my own house or at the job.

If you believe that 110.3(B) requires that we follow the instructions using a suretest is not a proper test anyway.

 

[don_resqcapt19]

Bill,
I don't think that I would hold the test button in for 5.6 seconds to see if it would trip...I expect it to trip when I push the button and if it doesn't I will replace it.
Don

 

[jim dungar]

Bill,
I don't think that I would hold the test button in for 5.6 seconds to see if it would trip...I expect it to trip when I push the button and if it doesn't I will replace it.
Don

How much fault current flows when using the test button versus other methods?
And of course the UL standard is for the MAXIMUM not the OPTIMUM tripping times.

 

[wptski]

If 25 ms for all fault levels meant the thing would be tripping frequently due to 'noise' I would want the variable trip time unit.

If they make GFCIs unusable they will not be any help at all.


As far as I am concerned if I install a GFCI and opens when I push the TEST button included on the GFCI I have a working GFCI and move on, be it my own house or at the job.

If you believe that 110.3(B) requires that we follow the instructions using a suretest is not a proper test anyway.

If the tester creates a 6-9ma imbalance like the test button does through a resistor does it matter?

 

[wptski]

Bill,
I don't think that I would hold the test button in for 5.6 seconds to see if it would trip...I expect it to trip when I push the button and if it doesn't I will replace it.
Don

Don:

The test button does trip as does the SureTest but why so slow compared to others? Are the others of better quality because they exceed specs? We are talking five times faster here.

 

[don_resqcapt19]

Jim,

How much fault current flows when using the test button versus other methods?

It is my understanding that the test button causes a 8 to 12 mA imbalance.
Don

 

[don_resqcapt19]

Bill,

The test button does trip as does the SureTest but why so slow compared to others?

I have no idea of why the time difference between the devices.
Don

 

[iwire]

If the tester creates a 6-9ma imbalance like the test button does through a resistor does it matter?

Well it only matters as you seem very concerned with the UL standards but UL says to use the test button on the GFCI for testing.

It is my opinion that the use of the sure test and it's many functions causes more questions then it solves.

Often (and this is not aimed at you) the sure test ends up in the hands of people that have little formal training (often home inspectors) but have read the literature included with the sure test and suddenly every home has severe electrical issues, from voltage drop to slow GFCIs. :roll:

They also have sure test version that they lead us to believe is an AFCI tester.....it's not, there is no such device on the market as a AFCI tester.

The only way to test an AFCI is with the button on the AFCI device.

All that aside Don brings up a good point, I would probably not push a GFCI test button for five seconds, if it did not trip using the test button on it within a second or two I would assume it is bad and replace it.

 

[wptski]

Well it only matters as you seem very concerned with the UL standards but UL says to use the test button on the GFCI for testing.

It is my opinion that the use of the sure test and it's many functions causes more questions then it solves.

Often (and this is not aimed at you) the sure test ends up in the hands of people that have little formal training (often home inspectors) but have read the literature included with the sure test and suddenly every home has severe electrical issues, from voltage drop to slow GFCIs. :roll:

They also have sure test version that they lead us to believe is an AFCI tester.....it's not, there is no such device on the market as a AFCI tester.

The only way to test an AFCI is with the button on the AFCI device.

All that aside Don brings up a good point, I would probably not push a GFCI test button for five seconds, if it did not trip using the test button on it within a second or two I would assume it is bad and replace it.

Well, at first I thought that the Leviton GCFI was out of UL specs but it isn't. The problem is the way GFCI specs are listed by the manufactures as minumum trip current being 4-6ma and a 25ms max. They don't seperate the two, it's not 25ms max at 4-6ma and that's where I went wrong. Still confusing is why other GFCI almost meet that time/load specs!

You'd be wrong in replacing a GCFI that took a few seconds to trip with the test button as up to 5.6 seconds is allowed.

You must be refering to this about AFCI's: http://www.mikeholt.com/mojonewsarc...I-Testers-versus-AFCI-Indicators~20050728.php. Yes, this is same Ideal tester that I'm using.

EDIT: I emailed Pass&Seymour asking about the trip time at 6ma. They replied by attaching a PDF which I've seen already. I states minimum trip current is 4-6ma and maximum trip time is 25ms! Here we go again.