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Being an licensed Industrial/commercial Electrician, I ran across a couple of concerns when reading a thread on dedicated circuits that need to be addressed.First. Someone mentioned the fact to use shielded fire alarm cable as a dedicated circuit. This is a dangerous thing to do. Fire Alarm cable is not UL listed to serve as a branch circuit. This is not its intended purpose specifically if its insulation is not rated to be used on 120volts. The insulation very well may not have an insulation rating capable of withstanding continous current that is supplying your Audio gear. You risk burning your house down. This is a National Electrical Code Violation. PLEASE HAVE A LICENSED ELECTRICIAN INPECT YOUR WORK IMEDIATELY.
Second. The driving of a second ground rod is prohibited if it's not bonded to your existing ground rod by the National Electrical Code. Any compitent Electrical Inspecter would fail such an installation. And any electrician that would intall such an intallation should have his license revoked! A dedicated grounding circuit is a circuit that has 2 grounds run with it. 1 mechanical ground and 1 insulated isolaton ground. The mechanical ground attaches to your box if it is of metal construction and to the recepticals yoke(metal strap on receptical used to attache receptical to box). The Isolated ground goes to the green screw of the isolated receptical. (please note that a normal receptical is not an isolation receptical. you must ask for a isolation receptical at the counter) This isolated wire runs without splice to anything else, all the way back to your main panel and attaches to the same bar as the other grounds. It does not go to your ground rod. Your ground rod is bonded at you main panel to the equipment grounding bar and neutral bar. The main panel is the panel where you servive wires from the utility come into. Not a sub-panel if you have one. All this is for your safety.
If you had two ground rods that where not bonded together, you could develope a differance in voltage at the two rods. Lets just say 100volts at one rod and 240 volts at the other. (arbitrare numbers).You would have a differance of 120 volts. That's enough to kill you under the rite circumstances. And you can recieve that shock simply by touching the metal enclosure of your audio gear and the metal enclosure of something plugged into a different circuit. A child can also be killed outside your home if some how got in-between these two potentials. Now some of you may not believe me or say what are the chances of that happening? Well I have been in the field for many years and have seen it happen? I knew an electrician who got killed when he got hung up on a differance in voltage between the ground rod and the aluminum siding on a house. Electricity sometimes will exhibit strange behavior.It's not something to be messed with by the unexpereienced. You can very easily without knowing, make a very dangerouse installation. I see such installations nearly everyday!Call an Electrician if you are un-sure of what you are doing.
Please heed these warnings so you will continue to enjoy this hobby for many years to come!Happy Holidays,
Tony
Follow Ups:
Thanks for the info.
Hi Tony,First, to clear confusion, RG214 I have mentioned is not a fire alarm cable. Look at the RS Web site, it is listed under stock No.388-631. It has equivalent of 13ga copper conductor and is rated for 1.25kV rms continuous operation. AFAIK, this cable is used for high powered HF operation (by example between HF transmitter and antennas).
Second, not living in US I am not inclined to study american safety standards, but described installation of the cable (separate runs of the cable for life and neutral, plus shield connected to the earth) is perfectly legal in many European countries and South Africa. Not my idea, anyway, look at the TNT site, link below.
Cheers,
Mirek
Yes you are correct that European electrical standards are different than the States, Actually much differnt. I just recently relocated a manufacturing line from England to GA,USA. This line originated in Holland. What a nightmare on my part. The Electrical Standards here in the states are much more strict from what I saw . I had to re-wire the whole machine to make it Code and OSHA compliant here.Maybe this cable is an exceptable method over seas, but here in the States it would not fly.
Tony
Hi, TonyWhat about if you remove PVC jacket from both cables leaving bare copper braid, twist them together, then there is no separate earth wires, just one twisted pair. Thin about, it might be worth. Have you visited TNT site?
Cheers,
Mirek
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The key thing that the American audio nuts need to know is that in most states, An electrical inspecter signed off on the electrical install of your home when it was first built. God forbid there was a fire, A fire marshall would determine the cause of the fire. If it is reported that an improper wiring install by an un-licensed electician/contractor was the cause, Your insurance company will not give you a penny! How much are you willing to risk?And as I mentioned in a previous post. Over seas electrical standards are much different than ours. So even though our European Friends are trying to help, thier guidance could get you into trouble. Another thing that I learned while in England is that European Electrical Terminology is also much differnt than ours. This in its self could create considerable confusion to someone that does not have experience with electricity. I had many intriguing conversations with the plant electricians in England about our differnt terminology. One thing that I will always find funny is that in England, an electrician bashes a house. In the states we call it roughing in a house. What would you think if I came to your house to wire your addition and said. "I'm here to bash your house"!!!!!
Tony
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I'm having dedicated lines installed this week by my brother-in-law, a licensed electrician. I'm sure he knows what he's doing, but I'll print this out and show it to him just in case.
Sal Gazzo in NJ
No need to print this if you brother-in-law is a Electrician in NJ. New Jersey is ranked among the toughest States to get a license in.What part of NJ are you from? I'm originally from Sayerville. I now reside in PA.
Tony
Hi Tony,
> No need to print this if you brother-in-law is a Electrician in NJ. New Jersey is ranked among the toughest States to get a license in. <
That's comforting! Actually, both my Father-in-law and his son are electricians and I've never heard anything but compliments about their work.
> What part of NJ are you from? I'm originally from Sayerville. I now reside in PA. <
I'm from West Caldwell. I know where Sayerville is, but I'm not familiar with the town.
Thanks again for the warning!
Sal
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