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Author Topic: Jersey City Power  (Read 6123 times)

John Roberts {JR}

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Re: Jersey City Power
« Reply #10 on: October 27, 2014, 11:24:07 am »

That looks like the low voltage 230V side. I share one transformer with two other neighbors, since hurricane Katrina took down my personal pole and transformer several years ago. I suspect they are less strict on the low voltage side of the transformer.

JR 
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Jonathan Johnson

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Re: Jersey City Power
« Reply #11 on: October 27, 2014, 11:42:23 am »

...saw this overhead power feed for houses near the church. This wasn't an isolated connection, since I saw of bunch of similar taps up and down the street.

Mike, I think that type of distro between the pole transformer and houses is fairly common. A closer look will reveal that there is a continuous messenger wire between poles; the only connection with strain is between the lateral messenger to the house and the main messenger, and if the connector is listed for strain (in both axes), then that shouldn't be a problem.

I really don't see a problem with it, unless there is something else I am missing. It's kind of hard to see fine detail on my phone screen.
« Last Edit: October 27, 2014, 12:29:04 pm by Jonathan Johnson »
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Jonathan Johnson

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Re: Jersey City Power
« Reply #12 on: October 27, 2014, 12:33:55 pm »

Mike, I think that type of distro between the pole transformer and houses is fairly common. A closer look will reveal that there is a continuous messenger wire between poles

That messenger appears to serve as the neutral between the transformer and the houses, and probably connects all the way back to the substation where it ties in to the neutral point on the secondary side of the step-down transformers. It likely provides a common bond between all of the transformers and loads (houses, shops, churches, etc.) on that circuit on the "low" voltage side of the substation. If properly wired, the EGC/GEC conductors as well as the neutral conductors of every device in every building will be tied together via this common conductor.

For single-phase POCO transformers that provide 120/240V service on the secondary side, the center tap of the secondary and one tap of the primary are usually connected by this common neutral/ground wire. The POCO usually also connects this to a ground rod at the base of the pole on which the transformer hangs. (Poles without transformers generally don't have a ground rod.)

Even so, because of resistance & impedance of the wires, there can still be a difference in ground potential between two houses on the same POCO circuit, so when powering sound systems from two different buildings, you should be prepared for that differential as it can be the source of ground loop currents.
« Last Edit: October 27, 2014, 12:37:14 pm by Jonathan Johnson »
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Tommy Peel

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Re: Jersey City Power
« Reply #13 on: October 27, 2014, 12:36:56 pm »

Mike, I think that type of distro between the pole transformer and houses is fairly common. A closer look will reveal that there is a continuous messenger wire between poles; the only connection with strain is between the lateral messenger to the house and the main messenger, and if the connector is listed for strain (in both axes), then that shouldn't be a problem.

I really don't see a problem with it, unless there is something else I am missing. It's kind of hard to see fine detail on my phone screen.

Looks like there is a continuous wire going between poles. Here's a slightly tweaked zoomed in version:
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Jonathan Johnson

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Re: Jersey City Power
« Reply #14 on: October 27, 2014, 12:49:01 pm »

They were installing new restrooms at the church and had all kinds of wiring and switches hanging out of their boxes. I didn't take any pictures of that because I was worried about being called on the witness stand if someone was electrocuted while I was teaching in the hall. Seriously, that's what I was thinking while taking a leak and staring at the bare wires hanging out of the box. Lucky for me, nobody died while I was teaching my seminar. ::)

What we do not understand, we fear. Fear leads us to do irrational things. When we gain understanding, fear is relieved and we can act rationally. But sometimes understanding heightens our fears; that is when the real danger of the situation becomes manifest. Understanding danger encourages us to gain the tools to mitigate risk, mitigating risk in turn relieves the danger.

Ignorance is not bliss; it is dangerous.
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Frank DeWitt

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Re: Jersey City Power
« Reply #15 on: October 27, 2014, 01:27:47 pm »

What we do not understand, we fear. Fear leads us to do irrational things. When we gain understanding, fear is relieved and we can act rationally. But sometimes understanding heightens our fears; that is when the real danger of the situation becomes manifest. Understanding danger encourages us to gain the tools to mitigate risk, mitigating risk in turn relieves the danger.

Ignorance is not bliss; it is dangerous.

I suspect that the only thing not understood was weather or not the wires sticking out of the box were energized.  If they were not a little sign saying pardon the mess we are working on it but nothing is energized.  If they were then Fear, at least for others who don't understand the risk was not irrational.
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Stephen Swaffer

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Re: Jersey City Power
« Reply #16 on: October 27, 2014, 02:05:20 pm »

A few weeks ago several volunteers from our church set up a carnival for a special Sunday-one of the attractions was a 37 foot tall inflatable slide.  They set up-IMO-uncomfortably close to an overhead primary-the top of the slide was 15 to 20 feet from the OH-within NFPA 70 guidelines for workers-but for kids?  Granted the platform had a canopy so it was the closest thing to the OH-but we had 100 yards or better empty space-absolutely no need to push the envelope.

Friday I was on a job site when another member came up to me and said he had seen something that morning that made him think of me.  As a first responder, he had responded to a double electrocution.  Two guys installing gutteres had lost control of an aluminum ladder (it was a blustery day) and tangled with a primary OH.  He was obviously shaken by the sudden, permanent aspect of their misjudgement.  He said he stood their looking at the burn marks on their hands feeling helpless asking himself if there really was nothing they could do for them-realizing they likely had families.  He no longer has a use for aluminum ladders-much better to carry a heavy one around-and I am guessing I would have a strong second for any future objections to close proximity to an overhead line.

Be careful setting up truss for your gigs! If not for yourselves for your families and the first responders.
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Lyle Williams

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Re: Jersey City Power
« Reply #17 on: October 28, 2014, 04:38:08 am »

Fiberglass is the way to go with ladders.

You need to watch out with wooden ladders, as some have metal wire reinforcement.
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Jonathan Johnson

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Re: Jersey City Power
« Reply #18 on: October 28, 2014, 10:48:41 am »

Fiberglass is the way to go with ladders.

You need to watch out with wooden ladders, as some have metal wire reinforcement.

The metal wire reinforcement is usually across the ladder, supporting the rungs. Electrically, this is no different than the metal rungs found on fiberglass ladders.

Now if the wooden ladder has metal reinforcement along the rail, watch out. But I don't think I've ever seen that.
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jasonfinnigan

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Re: Jersey City Power
« Reply #19 on: October 28, 2014, 02:54:06 pm »

Fiberglass is the way to go with ladders.

You need to watch out with wooden ladders, as some have metal wire reinforcement.

Wood can and has conducted electricity before, especially at high voltages... even more so when wet at lower voltages.

nothing is "non-conductive" just less-conductive (hence why people freak out when you tell them everything they though they new about electricity from HS classes is competently different at higher currents).
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ProSoundWeb Community

Re: Jersey City Power
« Reply #19 on: October 28, 2014, 02:54:06 pm »


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