Shock hazard - What would you do to correct it ?

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goldstar

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
I was called to inspect and/or correct a shock hazard problem for outdoor lighting at the lake community facility where I live. There is a 4-circuit outdoor breaker panel mounted on a utility pole adjacent to a volleyball court. Upon my initial inspection I could not find a problem until I replaced the cover to the panel and got whacked. It was hot, I was a bit sweaty but I couldn't duplicate the problem until I leaned back against the metal cyclone fence while trying to replace the cover. Bingo, I got whacked again. I measured the voltage from the outside of the breaker panel to the fence rail and got 120 vac.

This is what I discovered :
  • The facility is fed by a 120/208V, 3 phase power to the club house
  • The initial lighting circuit covering the basketball courts on the opposite side of the play area was 208 volts
  • Wiring to that light circuit was run with triplex (seemed OK since no neutral was required at the time that was installed))
  • Somewhere along the line (I guess when they created the volleyball area) someone decided to install 120 volt lighting and tapped off the 208 volt power line to the basketball courts. Now we're using the ground wire as a neutral
I ran a temporary ground wire from the breaker panel to the fence post and that seemed to correct the shock hazard problem for now but I know that really doesn't solve the problem. I plan on driving two ground rods at the utility pole as soon as possible. Running a quad-plex back to the club house would probably be the best way to correct this but at this point in time is not practical and would be cost prohibitive.

Anyone have any other suggestions ?

Thanks.
 
ptonsparky said:
Using your body as a tester is pretty rough on it, I recommend the Fluke T+ Pro.

Sounds like the fence is too close to the panel. Do you have the proper working space?
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Thanks for your reply. The power to the initial lighting scheme is 208V/1-phase. They didn't bring 3-phase out to the poles. This is a bit tough to explain but many moons ago in this lake community people (with a little knowledge) did the electrical work. Who knows if they even got permits or not. IMHO, if it was me making the decision I would replace the wiring to that specific utility pole to correct the problem. Right now I'm just looking to make it as safe as possible until the board of directors decides to spend some $$$ (which, in essence is my $$$ seeing as how I'm a member).:rant:

It wasn't my intention to use my body as a tester, but that's how I found the problem.:cool:
 
Shock hazard

Shock hazard

I bet you who ever done the electrical for the volleyball light is not a qualified person. I think you have the right ideal,the cost may be a little over but it cheaper than someone losing a life.:(
 
The killer in court will be, “you knew about it”.

You’re a member of this community, donate your time for free ;-) and get the others to do the digging, etc. Materials will be the only expense.

I wouldn’t want to be in your shoes if someone gets hurt or killed.

In the meantime isolate the lighting system, you have no other option.
 
goldstar said:
I plan on driving two ground rods at the utility pole as soon as possible.
Click to expand...
And exactly what do you expect that to accomplish? If a shock hazard exists, then a ground rod will never, never remove that hazard.

What you need to do is remove the cause of the shock hazard. I cannot quite visualize the wiring of this installation from your description. But it sounds like there is a connection between the 120V lighting system's neutral wire and the 208V lighting system's equipment grounding conductor. That has got to be removed immediately.

You say there is a 4-circuit panel. I infer it is a single phase panel. If there is a desire to have both 208V and 120V lighting fed from this panel, then there needs to be 4 wires to the panel from the facility's 208V 3-phase distribution. You need two hot conductors, a neutral conductor, and an equipment grounding conductor. You also need there to be no connections between the neutral and the equipment ground. Anything other than this configuration will not be safe.

 
goldstar said:
I plan on driving two ground rods at the utility pole as soon as possible.
Click to expand...
Some may contend that as soon as the panel was mounted on the utility pole, the utility pole became a "structure," as defined in the NEC. I am not convinced of that, but let's say that it is a "structure." In that case, 250.32(A) would require that a grounding electrode system be installed, and most of us would agree that the simplest way to achieve that is to drive two ground rods. But please understand that that will not alter the shock hazard in any way. The ground rods are not there to prevent a shock, and they cannot prevent a shock. That is not their job.

 
goldstar said:
I ran a temporary ground wire from the breaker panel to the fence post and that seemed to correct the shock hazard problem for now but I know that really doesn't solve the problem. I plan on driving two ground rods at the utility pole as soon as possible. Running a quad-plex back to the club house would probably be the best way to correct this but at this point in time is not practical and would be cost prohibitive.

Anyone have any other suggestions ?

Thanks.
Click to expand...

ptonsparky said:
The board should be taking your advice seriously. Turn it off or disconnect the 120v loads. You and they do not have a choice.

Ignorance is bliss, but neither of you are ignorant now.
Click to expand...

It's tempting to do a temporary fix but not a good idea.

I was asked to do some shoddy work for the park service because they don't get inspections ( ( federal property ). To dangerous for me. Fix it right or don't touch it.

The board may claim to be ignorant but it's hard for a licensed electrician to do so.
 
I am not familiar with a cyclone fence but is it also connected mechanically to some sort of electrical equipment elsewhere that's completing the circuit.
 
Simple: if it is totally cost prohibitive to run a neutral, you have to install a transformer with a 208V primary, hot to hot, and create an SDS with a 120V or 120/240V secondary and local ground rods.
But to me the larger problem is the presence of the shock voltage in the first place. Using the EGC as a neutral will not, by itself, put more than a few volts of potential between panel and fence.
Either there is a fault from hot to neutral or exposed metal that is just short of opening the breaker ( probably at a light pole) or the EGC wire is actually open somewhere.
Stray voltage from small leakage should not cause the symptom you report.

So there are two actions to take, both of which are required:

1. Find the fault and fix it.
2. Pull an EGC or create an SDS.
 
part of what golddigger said, is there anything about the fence that could be faulting to the fence, because just a metal fence alone will not complete a circuit of that much voltage. Is there an electric gate, lift, some type of equipment that is grounded/bonded to the fence.
 
GoldDigger said:
But to me the larger problem is the presence of the shock voltage in the first place. Using the EGC as a neutral will not, by itself, put more than a few volts of potential between panel and fence.
Either there is a fault from hot to neutral or exposed metal that is just short of opening the breaker ( probably at a light pole) or the EGC wire is actually open somewhere.
Stray voltage from small leakage should not cause the symptom you report.
Click to expand...

I was thinking same things as I was reading through the replies. Though using the EGC as a neutral conductor is not proper - if it is in good shape should not produce full 120 volts to other grounded objects like that.
 
goldstar said:
...I ran a temporary ground wire from the breaker panel to the fence post and that seemed to correct the shock hazard problem for now but I know that really doesn't solve the problem. I plan on driving two ground rods at the utility pole as soon as possible. Running a quad-plex back to the club house would probably be the best way to correct this but at this point in time is not practical and would be cost prohibitive.

Anyone have any other suggestions ?

Thanks.
Click to expand...
Ground rods will do nothing to correct the issue.
Is the fence hot or the panel enclosure hot?
 
kwired said:
I was thinking same things as I was reading through the replies. Though using the EGC as a neutral conductor is not proper - if it is in good shape should not produce full 120 volts to other grounded objects like that.
Click to expand...
If it is in good shape, then the only voltage to drive a shock would be the voltage drop on the neutral. That will not be high enough to even feel.
 
charlie b said:
And exactly what do you expect that to accomplish? If a shock hazard exists, then a ground rod will never, never remove that hazard.
Click to expand...
What I was trying to accomplish was to make the installation safer by creating an equi-potential bonding grid. The cyclone fence posts were embedded in concrete. I drove the 2 ground rods and bonded them to both the fence posts and the breaker enclosure.
What you need to do is remove the cause of the shock hazard. I cannot quite visualize the wiring of this installation from your description. But it sounds like there is a connection between the 120V lighting system's neutral wire and the 208V lighting system's equipment grounding conductor. That has got to be removed immediately.

You say there is a 4-circuit panel. I infer it is a single phase panel. If there is a desire to have both 208V and 120V lighting fed from this panel, then there needs to be 4 wires to the panel from the facility's 208V 3-phase distribution. You need two hot conductors, a neutral conductor, and an equipment grounding conductor. You also need there to be no connections between the neutral and the equipment ground. Anything other than this configuration will not be safe.
Click to expand...
I understand that and I have some new information regarding this installation. The lighting at this facility was installed in two separate phases and all were aerial runs. The basketball court area was installed first and the volleyball area second (years apart BTW). In addition there was a 120/240 volt service, telephone and CATV installed to the original clubhouse. The clubhouse was remodeled about 15 years ago and those original services, while disconnected in the street were never disconnected on the property or from the clubhouse. About one month ago a tree fell in the basketball area and pulled the abandoned 120/240 volt triplex off the club house and utility pole along with the EGC portion of the service to the lights and the abandoned telephone and CATV wiring. Wiring to the basketball area is a 120/208v single phase circuit and was run with quad-plex. I climbed up on the roof to the clubhouse and noticed that the EGC for that circuit was disconnected so I bugged that together. Looking up to the light pole in the basketball area I can now see that the EGC is disconnected from that as well but will need a lift to get up there. The neutral and both phases remained in tact.

Now for the volleyball area. Someone (in their infinite wisdom) decided to extend the light circuit from the basketball area to the volleyball area by using tri-plex instead of quad-plex. They used the EGC or strain relief wire as a neutral. Replacing that run with quad-plex will be a much easier fix than running a new circuit to the clubhouse. I plan to send a proposal to the association advising them of the situation but for now I believe I made the situation at the volleyball area safer than what it was by installing the rods and bonding the fence. There's no question that the triplex to that area has to be replaced.
 
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