[warnerwh]

I wonder why having your dedicated lines connected to their own grounding rod would be dangerous?  Is this because the neutral line is connected to the main ground and if so why would that cause a problem?

[ScottMayo]

I wonder why having your dedicated lines connected to their own grounding rod would be dangerous?  Is this because the neutral line is connected to the main ground and if so why would that cause a problem?

I'm not an electrician. Take my word for nothing.

You often want a single ground for a structure because different ground points have different effectiveness - a ground system is supposed to have 25 ohms or less, but two different systems won't have the same resistance, and that means potential voltages can form between the two systems. But it's not dangerous as far as I know - it's only annoying, because it can lead to hum. If anything, multiple grounds simply give extra ways for leaked voltage to leave. But if there is any question, consult an electrican. Given my experiences with electrcians, consult two, because a LOT of these guys seem to go on hearsay and rumor and I've gotten my share of wild answers from some of these guys.

If you install your own stuff, find and read your local code. Ground systems have specs that need to be followed. You want to exceed these specs: thicker wire, thicker ground rod if you use one, deeper hole. If you use an electrcian, find and read your local code. And make bloody sure he follows it. For example, if you have multiple grounding rods in the earth, they should be at least 6 feet apart.

If your hot or neutral line is connected to ground, that's BAD.

If you bring in cable TV, get them to connect their ground to whichever one you use for your stereo - you can get wicked hum otherwise.

I'm not an electrician. Take my word for nothing.

[Glen B]

I wonder why having your dedicated lines connected to their own grounding rod would be dangerous?  Is this because the neutral line is connected to the main ground and if so why would that cause a problem?

There is a potential danger from a lightning strike between the separate rod and main grounding electrode.  There is also a risk of electrocution should the equipment connected to the separate ground rod happen to develop a fault that energizes any exposed metal part(s).  Anyone coming into contact with the exposed part and any grounded surface can receive an electrical shock.  Also, in such a situation the overcurrent protection [circuit breaker] will not trip.  In an electrical branch circuit, fault current needs to get back to the source (the incoming neutral/utility company transformer) to quickly trip the circuit breaker.   This will not occur with a separate grounding rod because the earth's resistance is too high.  The earth is not a sponge that absorbs fault current.  The only way for the circuit breaker to trip in a timely manner in the presence of fault current is when the circuit ground is returned to the ground bar in the main service panel.   Likewise, the main grounding electrode (to which the incoming neutral is bonded) is only there to stabilize the supply voltage and help provide lightning protection, not absorb branch circuit fault current.   When a supplementary ground rod is used in any installation, it must be bonded to the grounding main electrode.

[Dan Banquer]

Glen is right! Please consult an electrician before you do anything!
                              d.b.

[andyr]

There is a potential danger from a lightning strike between the separate rod and main grounding electrode.  There is also a risk of electrocution should the equipment connected to the separate ground rod happen to develop a fault that energizes any exposed metal part(s).  Anyone coming into contact with the exposed part and any grounded surface can receive an electrical shock.  Also, in such a situation the overcurrent protection [circuit breaker] will not trip.  In an electrical branch circuit, fault curre ...

Glen,

While I agree that if you live in a highly-prone-to-lightning region of the world you might have to do away with separate earthing rods, perhaps you and Dan need to read what Ben Duncan has to say about this issue.

See here: http://www.britishaudio.co.uk/proaudioaccessoriesbd.html

AFAIK, Ben is a respected authority on such matters and what he sells is approved by the UK Electricty Authority.

Regards,

Andy

[Dan Banquer]

You must realize that this is against electrical code in this country and if anything bad happens your insurance company will not cover it.
And now I am going to speak my mind and vent and I don't give a crap who take  offense here:
Audiophiles are notorious for getting really bad advice and listening to it, especially when it comes to basic safety practices. If you feel your audio system justifies the potential of doing damage to property and threatening life and limb to you and your family, you really ought to keep it to yourself instead of endangering others. I have had equipment returned to me for repair from someone who did the separate grounding rod routine. He burned up circuit boards and was wondering why his surge suppressor didn't work.
The rest of you need to ask yourself, is it worth it to risk your property, yourself and your family before you do something stupid.
For further info on the National Electrical Code go to www.mikeholtz.com

SAFETY FIRST!
         d.b.

[Occam]

While locking this thread, Andyr's response to Dan was lost in the ether. With his permission I'm including it here -

Dan,

I wasn’t advocating people disobey their electrical code – they absolutely should not – merely pointing out that Ben Duncan’s separate-earthing kits appear to be accepted by the authorities in the UK.

I haven’t installed them in my own system (in Oz) for the very reason you described.

Regards,

Andy

MODERATORS ACTION

To my knowledge, separate (techincal) grounds are against code in residential environments in the United States. Those in commercial and technical environments should certainly not be using these boards for guidance. This is not a subject for discussion on this board, as the only folks who have valid advice are Electricians and P.E.s. Apologies to those who are outside the US whose codes may be different, but as Dan and Glen have commented, violations of code, at minimimum, jeporadize insurance coverage, and may well endanger life and limb....
This thread is now locked.