LOL, then they'd have to fill it with dirt or cement to prevent anyone falling in the hole!

crowny2 - 2009-08-20 10:30 PM

verga - 2009-08-20 9:08 PM

rach_1623 - 2009-08-20 9:38 PM I went to the University pool for the 1st time today to get in my swim work out and on my 8th lap, they tell me that I have to get out because there's lightning. I was like "...... uh..... you know this is an indoor pool, right?...." They were like "Yeah, the lightning can travel in through the building." I really wanted to yell at somebody cause this is the stupidest thing I've ever heard. I've seriously NEVER heard of this before. I was completely boggled by this. How do they think lightning is going to get in the pool?? It would take like an act of God or something to get through all the iron, concrete, roof, glass, ect ect to strike the pool. And it's NOT going to travel through the effing building. It's completely ridiculous. I've swam at my other pool in bad weather and nobody gave a crap. Seriously, I am *amazed* and I think whoever came up with that rule doesn't understand effing science. Go read a book on freaking electricity. Ai! I really wanted to just yell at someone but they were all college kids working there and obviously they didn't make up the rule. So very frustrated!!!!! 

Let me expalin the "effing" science to you.
The roof at the pool I go to is made out of metal whcih is a conductor. It is supported by "H" beams also made out of metal. Attached to the ceiling are lghts, the conduit that has the wires in them are also made out of metal and are attached to the metal roof supports. So genius do you really want to be in water which is also a conductor during an electrical storm?
seems to me that perhaps you owe those college kids a thatnks you and might want to pick up a book on "effing" science.
But what do I know I have only been teaching electircal theory and Architecture for 14 years with 2 Bachelors degrees, a Masters degree in Education and the equivalent of another in Engineering, but what the heck do I know about it?

Dude.  Think you could have put that a little nicer?  The guy was a little upset but you didn't need to attack him.  Just calmly explain the science behind it.  Sheesh.  Chill out.

In short his post could have been a whole more polite as well, and should have been!

If I was a pool owner/administrator, I would totally close during a t-storm.  I wouldn't want to have my butt sued and I am sure that it would be since there is a potential risk, albeit a small one. 

To the OP.  Been there, done that.  At least I hadn't got in the water yet.  I just saw the sign at the gym's entrance (also university).  I didn't have my other workout clothes with me so I had to turn around and go home.  Very frustrating but for our own good.

You can actually get elecuted in your shower at home if you do not have proper grounding.  BTW, I am a degreed electrical enginneer.  I'm not saying that to claim that I'm am experct on all things electrical but I do know something about the phenomena of electricty.

Several years ago we had a bad storm come across our property with lightening hitting the ground all around out house.  The next morning my wife went out to feed our horses and found both of them laying dead in our pasture.  Lightening had hit the ground in and killed both of them.  It also fried our air conditioner as it blew hole in the copper tubing of the heat pump and caused oil to get into the copressor.

Back to the pool.  We have an in-ground fiberglass pool in our back yard.  I went out one day barefoot and stuck my hand in the water to get something and it felt like acid was on my hand!  I checked and rechecked and realized I was getting shocked from the pool.  I began a methodical search for the source of the current.  Turns out there was a difference between earth ground and nuetral and that potential was enough to shock me.  With my wet feet standing on the concrete (earch gound) and my feel at nuetral (the pool gound is tied to the nuetral).  

Anyway, I could spend hours talking about this...but I won't.  Suffice it to say you can get electrocuted in a swimming pool if lightening stikes some structure, electrial wire or the ground near the pool. 

I've got a white paper on stray current if anyone is interested....I'll paste in the section on the shower.

~Mike

VI.    The case of THE SHOCKING shower

A forty-year-old professional woman had a modern bathroom addition installed on grade.  It contained a large whirlpool tub and a stall shower, which was located in the middle of the area.  It was not unusual for her to receive an electric shock when standing in the shower, with the water running, and she touched the water control valve.

The writer first encountered persons receiving an electric shock when standing in a shower back in the early 1970s at a camp ground shower house.  Since that time reports of shocks in showers have continued. 

The first response of most persons is to bond the shower water control valve to the floor drain.  In many cases, this is impossible.  In the case under discussion, the shower was in the middle of the room without any access to either the piping or the floor drain.  In the case of the camp ground there was no floor drain, just a gutter running the length of the shower building.

Bear in mind that a bonding jumper still has current flowing through it.  Placing a person across the two points of the bonding jumper could result in current flowing through the person.  In the example shown in Figure 2 and Table 1, place a person across the points C and D in addition to the jumper.  There would be three paths for the current to flow.  Granted, the resistance of a person would be much greater than the other two paths, but according to the laws of electricity, some current will flow through the person.  Should the person have an open cut or abraded skin, there may not be sufficient resistance to prevent harm.  It probably will be insufficient current flow through the person, however, do you want to take that chance?

Substations, where high fault currents can occur, an underground grid is installed and bonding to metal structures are made to reduce the step-touch potential hazard.  Calculations are made to insure the reduction of the potential to safe levels. 

Stray, continuous currents in the twenty ampere range have been recorded flowing on water piping within residential areas.  When bonding jumpers are installed there are no calculations made to insure the touch potential

The solution is to find the source of the stray, continuous, uncontrolled current flow or to prevent the current from flowing over paths that could cause harm.

A.   Free Advice.

When the client sought advice on how to correct the shocking situation, the following free advice was offered.

1.       Obtain an electrician to check the residence’s service entrance wiring, grounding electrode(s), and the wiring within the house.  After obtaining assurances that the wiring meets the NEC,

2.       Contact the local utility and request their help.  If the local utility fails to resolve the problem,

3.       Write to the Public Utility or Service Commission outlining the problem and what steps have been taken and the lack of results.

The client proceeded through the above steps and when the Public Service Commission return the letter to the local utility, the client called for help.  One of the problems was the local utility Troubleman treated the client as if she was crazy and told her there was nothing wrong with the utilities’ wiring.

B.       Finding the Problem

With the help of an electrician, we proceeded to investigate the wiring within the house.  The grounding was satisfactory.  The copper water piping was bonded and there was a ground rod drive outside and next to the house.

With a meter, current measurements were taken on the ground wire to the ground rod, the connection to the water piping, and other locations.  At the time, mid-morning in April, there was little load on the transformer serving the house. 

All of the breakers were turned off and the neutrals were disconnected.  Each neutral was measured for the resistance between the neutral and it’s associated circuit and earth.  All of the readings were in the high ohmic region and indicated there was no neutral to ground faults and were acceptable.

There were two exceptions, the range and dryer.  They were wired using the neutral as not only the neutral, but also as the ground.  This practice was changed with the 1996 Edition of the NEC, after repeated attempts, over 21 years, to change the NEC.  In addition, the dryer was mounted over the washer and contact was make between the two.

The new bathroom was constructed on grade.  Approximately 6 m (20 ft) of copper water piping was buried in the concrete pad.  The copper piping, being a conductor, and buried in the concrete, which was in contact with the earth, made an excellent grounding electrode.

At the time, with little load on either the house or the transformer supplying the house, a voltage measurement was made between the shower water control valve and the floor drain.  A voltage of 0.5 volts was recorded.

This may appear to many as being insufficient, however as the electrical load increases, the voltage will also increase.  This is just part of the puzzle.  Where is the current coming from needs to be resolved.

C.      The Possible Sources

The utility transformer serving the house also served four other houses.  The area consisted of houses on two-acre or more of land, in a wooded area.

On one side of the client’s house was a pad-mounted transformer supplying the adjacent house.  (See Figure 3.)  With the excellent Ufer ground formed by the concrete encased copper piping, some of the primary current could be returning over the earth and entering through the buried piping.  This primary return current’s path would be over the copper piping to the service entrance to the messenger-neutral-ground conductor, back to the pole mounted transformer where the common ground-neutral conductor is located.  The common ground-neutral conductor returns to the substation, thus completing the circuit.

The second source of stray uncontrolled current could be coming from one or more of the other houses served from the pole mounted transformer.  The messenger-neutral-ground conductor could have corroded forcing the neutral return current to flow over the water piping or earth back to another connection to earth and onto the messenger-neutral-ground conductor and back to the transformer.

 In order to prove to the utility that the source of the stray uncontrolled current was not coming from the wiring within the client’s house another test would have to be made.  At

Figure 3.

Plot Plan

the last pole before her house, the two phase wires were disconnected.  With the two phase wires disconnected there was no current flowing into the house.

The conductor serving as the messenger-neutral-ground wires still connected.  An ammeter was used to measured any current flow over the messenger-neutral-ground conductor.  A current flow of 0.17 amperes was recorded.  This was proof that the stray uncontrolled current was coming from a source outside the client’s house.

D.      The Meeting of Minds

Armed with this information a meeting with the local Troubleman was arranged.  The area electrical utility engineer accompanied him.  With preliminaries out of the way, a request was made for a separate isolation transformer to be installed to protect the client from future stray uncontrolled current flow with a neutral blocker.  (A neutral blocker is installed between the windings of a transformer to prevent the transfer of primary current into the secondary connection.  See Figure 5, points PN and SN.)

The reply was expected,  “We do not install isolation transformers.  The problem is within the house, not our system.”

A simple request was made to prove the problem lay outside the house.  Drop the phase wires and measure for current on the messenger-neutral-ground conductor.  When current was found on the messenger-neutral-ground conductor, they indicated they would find the problem and correct it.

This was unsatisfactory.  Although finding the source and correcting it is the recommended solution, it would not protect the client from future failures.  If it was the a corroded messenger-neutral-ground conductor, it could corrode again either the same or at a different spot in one, two, five or more years.  If it was the primary neutral return current, a primary neutral blocker would have to be installed.

The problem finally landed on an engineer from headquarters.  This person was familiar with uncontrolled stray current flow over swimming pools and showers.  He was very receptive and indicated he had requested the utility to purchase isolation transformers to be installed in just such cases as this one.  However, the request was rejected by his superiors.

In order to confirm the problem, a better part of a day was spent measuring the voltage from every ground on the circuit.  The transformer under question was at the end of the circuit, which was about a mile long.  The procedure was to walk out from the pole and ground rod an arbitrary distance and drive a temporary rod into the earth and measure the voltage between the pole’s ground rod and the temporary rod. 

Agreement was reached.  He would recommend a separate transformer with a neutral blocker be installed and would generate a new standard.  The standard would show a neutral blocker installed and the transformer would serve only one house.

The installation was made, except the two ground rods, one for the transformer secondary neutral and the other for the neutral blocker, were not spaced 6 m (20 ft) apart.  If the rods were any closer, their sphere of influence would impinge on each other.  The result would be the pseudo “connection” between them, nullifying their required separation.

VII.   Transformer Connections

Non-utility electrical engineers expect a transformer to be connected as shown in Figure 4.  However, this is not the case for utility transformers.  Pole mounted, pad mounted and underground utility transformers have the primary neutral connected to the secondary neutral as shown in Figure 5.

A neutral blocker normally used on dairy farms services, acts like a lightning arrester.  It is placed between point PN and SN in Figure 5.  When the voltage exceeds a set level, the neutral blocker closes, permitting current to flow between the primary and the secondary.

Figure 5 shows some of the paths that the uncontrolled stray current can take.  The amount of current flow is dependent on the impedance of the various paths.

Having actually witnessed lightening traveling inside through a building, I tend to be more in agreement with the facilities that close their pools during thunderstorms. Granted, the building I was in was a house, not a structure that was probably built from steel and concrete, but it scared the poop out of me (and the dog, who I met under the table), so I am wary. It was a crazy day because, in fact, lightening went through all three buildings on the property: the house, the dorm, and the stables (this was a summer riding camp). In the dorm, one of the girls saw it come through an electrical outlet. In the stables, lightening blew out the portable radio and literally knocked the glass over the dial out and across the tack room. Luckily no one was hurt.

I think they probably just don't like you and were conspiring against you. Doubtful they had your safety in mind.

verga - 2009-08-21 4:14 AM

crowny2 - 2009-08-20 10:30 PM

verga - 2009-08-20 9:08 PM

rach_1623 - 2009-08-20 9:38 PM I went to the University pool for the 1st time today to get in my swim work out and on my 8th lap, they tell me that I have to get out because there's lightning. I was like "...... uh..... you know this is an indoor pool, right?...." They were like "Yeah, the lightning can travel in through the building." I really wanted to yell at somebody cause this is the stupidest thing I've ever heard. I've seriously NEVER heard of this before. I was completely boggled by this. How do they think lightning is going to get in the pool?? It would take like an act of God or something to get through all the iron, concrete, roof, glass, ect ect to strike the pool. And it's NOT going to travel through the effing building. It's completely ridiculous. I've swam at my other pool in bad weather and nobody gave a crap. Seriously, I am *amazed* and I think whoever came up with that rule doesn't understand effing science. Go read a book on freaking electricity. Ai! I really wanted to just yell at someone but they were all college kids working there and obviously they didn't make up the rule. So very frustrated!!!!! 

Let me expalin the "effing" science to you.
The roof at the pool I go to is made out of metal whcih is a conductor. It is supported by "H" beams also made out of metal. Attached to the ceiling are lghts, the conduit that has the wires in them are also made out of metal and are attached to the metal roof supports. So genius do you really want to be in water which is also a conductor during an electrical storm?
seems to me that perhaps you owe those college kids a thatnks you and might want to pick up a book on "effing" science.
But what do I know I have only been teaching electircal theory and Architecture for 14 years with 2 Bachelors degrees, a Masters degree in Education and the equivalent of another in Engineering, but what the heck do I know about it?

Dude.  Think you could have put that a little nicer?  The guy was a little upset but you didn't need to attack him.  Just calmly explain the science behind it.  Sheesh.  Chill out.

You're right, I could have been, but his were beyond the pale. Did you also send a post to him stating something to the effect of "Hey they were doing it for your safety, chill out"?

In short his post could have been a whole more polite as well, and should have been!

He is a she.  And she was venting.  Venting not at people but about a situation.  Bit of a difference.

newleaf - 2009-08-21 8:19 AM

crowny2 - 2009-08-21 9:17 AM

rach_1623 - 2009-08-20 9:38 PM I went to the University pool for the 1st time today to get in my swim work out and on my 8th lap, they tell me that I have to get out because there's lightning. I was like "...... uh..... you know this is an indoor pool, right?...." They were like "Yeah, the lightning can travel in through the building." I really wanted to yell at somebody cause this is the stupidest thing I've ever heard. I've seriously NEVER heard of this before. I was completely boggled by this. How do they think lightning is going to get in the pool?? It would take like an act of God or something to get through all the iron, concrete, roof, glass, ect ect to strike the pool. And it's NOT going to travel through the effing building. It's completely ridiculous. I've swam at my other pool in bad weather and nobody gave a crap. Seriously, I am *amazed* and I think whoever came up with that rule doesn't understand effing science. Go read a book on freaking electricity. Ai! I really wanted to just yell at someone but they were all college kids working there and obviously they didn't make up the rule. So very frustrated!!!!! 

He is a she.  And she was venting.  Venting not at people but about a situation.  Bit of a difference.

Not quite.

Sorry, she wasn't venting at people on this forum.  My problem was the perceived attack on her directly. 

Fine.  Both were in the wrong.  Feel better?

Must be a taper week.

Quote of the week.  I may add this to my sig.  ;-)  I'm still LOL at this.