Lots of sparks

[iwire]

I apologize to Bob again

No need to.

Bob was nice about it, maybe someone should tell me to sh*tup:roll:

No reason for that either, truth be told I end up running EGCs quite often but it will never be automatic for me. When I was assigned to a factory for about year total I ran EGCs for everything and many times redundant EGCs. It was the customers wish and they supplied the material.

But left up to me I like to choose the wiring method for the particular job at hand.

It is my belief that when people always do a task one certain way that means at times it will not be the best way for the task at hand.

 

[76nemo]

Thanks Bob, quick question. While you were at the amusement park, did you pull EGC's? I know the park is a little different scenario in some peoples eyes, but the question stands. The park payed, did you pull?

 

[iwire]

Thanks Bob, quick question. While you were at the amusement park, did you pull EGC's? I know the park is a little different scenario in some peoples eyes, but the question stands. The park payed, did you pull?

Yes, at least for the outdoor attractions, yes and no in the various buildings.

Considering I was the house electrician holding the electrical permit for the property I was in the drivers seat as to how we would do things.

But large projects had to be priced and run through the office so I was not in a position to plan without some eye on the numbers. When possible I did the outdoor work in aluminum rigid conduit and stainless steel enclosures. I was also moving away from line voltage operator controls to low voltage controls.

 

[76nemo]

Yes, at least for the outdoor attractions, yes and no in the various buildings.

Considering I was the house electrician holding the electrical permit for the property I was in the drivers seat as to how we would do things.

But large projects had to be priced and run through the office so I was not in a position to plan without some eye on the numbers. When possible I did the outdoor work in aluminum rigid conduit and stainless steel enclosures. I was also moving away from line voltage operator controls to low voltage controls.

What else got contracted out? The reason I ask is because the couple of plants where I worked contracted stuff that the in-house could of done, but didn't have time for. Mostly pipe work. If you are out there Ken in NC, I will always appreciate your work and friendship.

 

[iwire]

We did not contract any electrical work during my 5 years there.

I did use a company @ T&M to handle repairs of the 4160 V distribution. I could do some of the overhead repairs but none of the underground portions.

 

[76nemo]

That's all you had coming into the park was 4160? How big of a park was it?

 

[iwire]

That's all you had coming into the park was 4160? How big of a park was it?

Not to big, here is what it looked like 5 or 6 years after it closed it was no modern them park. It was local park that had operated from about 1875.

Tons of other pictures here

13.8 KV to the property edge, three 4160 feeders from there to various areas.

We had about 10 kiddie rides, 20 adult rides with about 5 of those being large. Flume, coaster, free fall etc.

We also had Shore Dinner hall that could seat 3000, one banquet hall for 600 guests and another banquet hall that could seat about 2000 or stand about 5000 for a concert.


My apologies to ptonsparky for the thread hijack.

 

[brian john]

Regarding the original post and the nonoperative GFP. This is a violation and a major life safety issue, much less the amount of down time that would/could be a result of the damages sustained during an arcing ground fault.

Not sure of the liabilities but anyone aware of this situation could (MAYBE) be held accountable should injuries/death result from an arcing ground fault. Then there is the personal responsibility from having a conscious.

 

[iwire]

Not sure of the liabilities but anyone aware of this situation could (MAYBE) be held accountable should injuries/death result from an arcing ground fault.

I agree, that seems entirely possible if a qualified person knows of the problem and does not follow up on it.

ptonsparky how every you handle this situation document everything, keep copies and get the info to those responsible for making decisions. In other words pass the responsibility up the chain.

 

[76nemo]

My hat's and prop's off to Bob. Thanks for keeping the park up and running! I have the sense you were NOT paid what you are worth. Thanks brother.:smile:

 

[ptonsparky]

The two guys in the know at the plant are both retiring within the next 6 months. Sounds like some good advice. Might write some other stuff down to. Thanks.

 

[peter d]

Tons of other pictures here

But no pictures or you?

 

[76nemo]

He was hiding with chips in hand, you got caught Peter, Bob scurried:grin:

 

[wirenut1980]

As long as it's your money your spending all is good.

When it's coming out of my bonus and

• specs do not require it
  
• the NEC code cycle after code cycle says conduit is effective
  
• and the fact remains that a properly installed steel conduit has a lower impedance then the copper EGC inside it

I will not automatically install an EGC. :smile:

Good advice from others regarding the handling of the non-operative GFI. That really needs to be corrected.


Sorry for getting in late here, iwire, but I have to disagree with your last bullet point. The Kaufmann Experiment in the 1950's showed different results:

The Kaufmann Experiment
This experiment, which was conducted in the early 1950s (Kaufmann, 1954), illustrates the importance of routing the ground conductor with the power conductors. The experiment setup (Figure 17) illustrates the typical arrangement that can be found on any job site. A current source was connected to the phase conductor and to pairs of possible ground return paths, which included a #4/0 conductor run with the phase conductor, and a #4/0 wire run 1 foot (0.3m) away from the rigid conduit and structural building steel. In a comparison of the relative impedances of 100 feet (30 m) of the rigid steel conduit vs. the insulated #4/0 ground conductors routed external to the conduit, 95% of the fault current flowed on the conduit, and only 10% flowed on the equipment grounding conductor routed outside the conduit. The impedance of the conduit was nine times less than the impedance of the grounding conductor routed external to it.

However, when the #4/0 equipment grounding conductor was routed with the phase conductor inside of the conduit, 80% of the fault current flowed in the equipment grounding wire, and only 20% flowed in the conduit. This experiment proves conclusively that the fault current that will flow through a ground conductor will be much higher when it is routed with the phase conductor. In the event of a fault, the circuit-protection device will be tripped much more quickly because of the high fault current, which minimizes the duration of the hazard. The results of the Kaufmann experiment are a primary reason why electrical codes require grounding conductors to be run with phase conductors.

When the building steel was compared to the rigid conduit, 95% of the fault current flowed on the conduit; only 5% flowed on the building steel.

I am having a hard time finding a good reputable source online, but I quoted the above from this link.


I do agree that steel conduit is an accepted safe method for an EGC, but as has been said many times, it needs to be maintained!

 

[LarryFine]

This experiment proves conclusively that the fault current that will flow through a ground conductor will be much higher when it is routed with the phase conductor.

That may be the case, but that's not what the debate is about. To make the test relevant, they should have compared fault current using conduit only with fault current using a properly-routed EGC.

The test you quoted only compares relative EGC current with the conductor either inside or outside the conduit. Nobody is likely to claim that an external EGC performs better than an internal one.

 

[LarryFine]

When the building steel was compared to the rigid conduit, 95% of the fault current flowed on the conduit; only 5% flowed on the building steel.

That sounds like an endorsement of the effectiveness of using a conduit as an EGC. It should out-perform the building steel current pathway.

 

[iwire]

That may be the case, but that's not what the debate is about. To make the test relevant, they should have compared fault current using conduit only with fault current using a properly-routed EGC.

The test you quoted only compares relative EGC current with the conductor either inside or outside the conduit. Nobody is likely to claim that an external EGC performs better than an internal one.

Thanks Larry, that was exactly what I noticed as well.

wirenut1980, the primary reason the conduit can provide a lower impedance path then a wire EGC inside it is the fact that there will be a whole lot more of it.

 

[Mike01]

Grounding conductor or Not??

Grounding conductor or Not??

I agree the NEC does not require to run an EGC that the conduit is an effective fault clearing path, however the code is a minimum standard if the owner wants it , the can have it. I see it typically in all the specifications and a lot of EE?s will then use this in the VE process, however I believe a lot of specifiers require it because the conduit path is based on so many things out of the EE?s control, the PROPER installation of the conduit, Joe Blow not running into with a forklift as eluded to in earlier posts. Once again I agree that as it may not be required if the owner is willing to pay for it who am I to say. And just for the record I'am all for it.

 

[wirenut1980]

That may be the case, but that's not what the debate is about. To make the test relevant, they should have compared fault current using conduit only with fault current using a properly-routed EGC.

The test you quoted only compares relative EGC current with the conductor either inside or outside the conduit. Nobody is likely to claim that an external EGC performs better than an internal one.

True, but it also takes each case of EGC run inside the conduit and run outside the conduit and compares with steel conduit. In the case of EGC run inside the conduit, more fault current flowed on the EGC than on the conduit. That is the point I was making.

 

[wirenut1980]

That sounds like an endorsement of the effectiveness of using a conduit as an EGC. It should out-perform the building steel current pathway.

Agree 100% and never said otherwise.:grin: