Isolation Transformer Grounding

[gar]

080628-2059 EST

Bob:

Because you follow code does not necessarily make something safe, not following code does not necessarily make something unsafe. The code does a lot of good, but in some areas it also may be further dumbing down the US population and making them less responsible for their actions because they are supposed to be protected from everything by someone else.

Personally I see no need for sliding protective covers over the slots in an outlet. These may become a real reliability problem. Children need to be taught to not put something in one of those slots.

Was or is aluminum branch wiring safe because it was allowed?

Are outlets with poor spring fatigue life safe? Somehow they got UL listing. I encounter these in motels where the plug falls right out.

Are outlets with spring contact termination safe compared to a screw clamp?

If you put excessive rules on business they will be ignored, go out of business, or go somewhere else like China or India.

I am not trying to negate the good of the NEC code.

Still the the original question problem is what problem needs to be solved.

.

 

[iwire]

080628-2059 EST

Bob:

Because you follow code does not necessarily make something safe, not following code does not necessarily make something unsafe.

I agree 100%, that is not in argument at all.

However when we start feeling we are smarter then over 100 years of code development we are certainly going down a slippery slope.

The code does a lot of good, but in some areas it also may be further dumbing down the US population and making them less responsible for their actions because they are supposed to be protected from everything by someone else.

I also agree with that to a large extent.

Personally I see no need for sliding protective covers over the slots in an outlet. These may become a real reliability problem. Children need to be taught to not put something in one of those slots.

That would be great, but is not happening. 2,400 kids a year in the US make trips to the Emergency room for injuries from receptacle outlets, that is about 6.5 per day. The statistics from Canada mirror that percentage wise.

European devices are already guarded and have been for years.

If you put excessive rules on business they will be ignored, go out of business, or go somewhere else like China or India..

I also agree with some of those points as well.

None the less 70E is coming and eventually will make it's way to the testing benches.

In most cases it would not be hard to comply with the rules as the Arc flash energy at a test bench is usually very low so all you will need is protection from the shocks.

And as Dereck noted there are other ways to work that are in compliance. IMO the safer ways are usually pushed aside strictly from laziness. We all fall into that rut.


Edit: I had to adjust my figures

 

[mivey]

Edit: I had to adjust my figures

That's handy soemtimes isn't it?:smile:

 

[iwire]

That's handy soemtimes isn't it?:smile:

Sure is and I can do it and you can't. :grin: :grin: :grin:


But the fact is I have edited posts for people that have made errors beyond simple spelling since the edit ban went into effect.

All it takes is a PM explaining the situation and I may well edit it if it does not screw up posts that may have been added.

I am not going to be fixing spelling and grammar mistakes. :smile:

 

[mivey]

Sure is and I can do it and you can't. :grin: :grin: :grin:

Feel the power!:grin:

 

[iwire]

Feel the power!:grin:

I can no longer fit my over sized head through standard size doorways. :grin:

Seriously, if you have something that really needs editing, just send a PM. :smile:

 

[mivey]

I can no longer fit my over sized head through standard size doorways. :grin:

Seriously, if you have something that really needs editing, just send a PM. :smile:

I can't think of anything that I post being that important. A re-post works fine for me.:smile:

 

[iwire]

In one instance a member made well thought out post but one of the included code references was wrong, he asked me to fix it and it was obvious he had the right one in mind.

The edit ban is about preventing an upset person from deleting all their posts.

 

[mivey]

In one instance a member made well thought out post but one of the included code references was wrong, he asked me to fix it and it was obvious he had the right one in mind.

The edit ban is about preventing an upset person from deleting all their posts.

Well, if you get upset, we would definitely gain some server space.:smile:

 

[iwire]

Well, if you get upset, we would definitely gain some server space.:smile:

I know your joking but that is a real issue as far as moderators go.

A well known moderator on another forum got upset and deleted the entire electrical section 'for the good of all' :roll:

 

[chris kennedy]

The edit ban is about preventing an upset person from deleting all their posts.

Marc can't even clear his PM box.

 

[mivey]

I know your joking but that is a real issue as far as moderators go.

A well known moderator on another forum got upset and deleted the entire electrical section 'for the good of all' :roll:

I estimate you are about 4.7% of the 500k posts. If you don't mind me asking, how much server space does all of this require and what is the fill rate running?

 

[iwire]

If you don't mind me asking, how much server space does all of this require and what is the fill rate running?

I have no idea, I just sit at my home looking at the same forum you do. My screen shot just has a few more buttons.

I have wounded about that as well, I imagine that all this text takes up very little server space, and the size of the files uploaded is limited. Still I would like to see all the statistics.

 

[iwire]

Marc can't even clear his PM box.

LOL, I think that may be a personal issue. He is definitely one of those 'pack rat' types. Never gets rid of anything. I bet his garage would be a interesting tour.

 

[mivey]

I have no idea, I just sit at my home looking at the same forum you do. My screen shot just has a few more buttons.

I have wounded about that as well, I imagine that all this text takes up very little server space, and the size of the files uploaded is limited. Still I would like to see all the statistics.

I think it would be some good info for our members who may not appreciate the scope of work involved. Maybe you could ask the IT guys to compose a little "behind the scenes" post-it that could be put in the FAQ section or something.

 

[mivey]

I bet his garage would be a interesting tour.

You go in first, we'll be right behind you!:grin:

 

[Ground Loop Guru]

Floating Ground at Isolation Transformer Output

Floating Ground at Isolation Transformer Output

Bob there is continuity from the EGC plug to the recepts ground, same for the Tripp-Lite transformers I linked too. Only exception might be the Medical ones from Tripp-Lite

Have you actually confirmed this continuity with an ohmmeter? The so-called "spec sheet" at the Tripp-Lite website (for the IS-250, for example) gives no clue about grounding. It only makes it clear that neutral and ground are tied internally. Their spec sheet is a fine example of "dumbing down" by marketing folks. But the Equi-Tech unit is even more "gullible audiophile" oriented - especially the nonsense about power factor!

I'm very interested in the actual connections inside such cord-connected isolation transformers because my students invariably ask me if they will help with ground loop issues in audio and video systems. Disconnection of safety ground on laboratory equipment generally doesn't improve matters much anyway because of the remaining leakage current issues. This is especially true when attempting to make the unbalanced input of an oscilloscope "float" and then make a differential measurement. The best solution is generally an isolation transformer on the SIGNAL line feeding the oscilloscope.