another mayday from the ungrounded apartment

[aussersein]

(Preface: this turned out to be a far longer post than planned. It might also be dead dull and describe a problem to which no one else in this forum can relate. That said, enjoy!)

Hey all,

Thanks (especially to fish_man) for all the advice on not pestering my neighbors below with my audiophilia. They're heading out of town this Thanksgiving, so I anticipate a ML-heavy holiday.

I have no formal electrical training, but a love of 2-channel audio and a couple of years spent wiring home and car audio systems taught me the value of having a good path to earth for one's equipment. As I mentioned on my last off-topic audio post, I live on the second floor of an apartment built in the 1950's, before 120v grounded AC was the standard. In my haste to find a comfy residence for the right price and in a good location, I was remiss in my electrical due diligence, and I overlooked all the ugly two prong plugs staring at me as I signed my lease. So, when it came time to wire up the 5.1 and tv, the computer, and my beloved two-channel system, I bought a home electrics book and a bunch of ground fault indicator outlets and went to work.

Pulling out the old outlets to replace them with the GFIs, it was alarming to see the state of the wiring in my apartment's walls: Old, hardened insulation over aluminum or tinned copper wires, knurled and kinked into ancient housings filled with gravely chunks of plaster and lead paint. My book suggested trying, but the multimeter found no ground path through the metal backboxes. In the end, I wired up the GFIs and tried to forget that they weren't grounded as I plugged in the equipment that I so value.

While I am confident that with the GFIs my electronics are protected from surges and lightning strikes, I would love to find a way to give my audio system true ground. However, I have to temper this impulse with the knowledge that I can't do any permanent work to the apartment, and that getting a ground path for my stuff might not be essential.

As far as I can tell, my system runs quietly and sounds good. All my 2-channel equipment is plugged into a TrippLite voltage regulator, which in turn is plugged into a single, ungrounded GFI outlet. I've never pulled enough amps to trip the GFI, thunderstorms pass over harmlessly, and I have never heard the dreaded "hum" associated with lots of equipment and multiple outlets and ground paths. So, to those that know, should I just forget about grounding my system and be happy? If grounding is a big deal, is there a way to do it in an old, second-floor apartment without forfeiting the security deposit?

If you've read this far, please be so kind as to follow the link below to a picture of my system - the window behind the MLs and components has an exposed, disused telephone line that runs down the apartment wall and into a box below; is there any way to get ground off of that? Also, while I don't want to tear up my walls, I have no compunction towards running a thin wire through that window to a ground if there's a way to do it without driving long metal stakes into the dirt.

Well, that's it. Thanks for reading and for any advice you may have.

My system: http://www.martinloganowners.com/forum/showthread.php?t=7607

 

[Gordon]

While I'm not an electrician, I'd be leery of running an unapproved wire in a building with unknown/questionable electrical system. If not done correctly, you are putting yourself and others in the building in jeopardy of fire.

It seems you've done as much as you could with what you have. I might suggest you discuss with your insurance agent the possibility of upgrading your renters insurance to cover replacement cost if it is not already included.

By the way, I'm not an insurance agent either!

Gordon

 

[Bernard]

I have no compunction towards running a thin wire through that window to a ground if there's a way to do it without driving long metal stakes into the dirt.

Typically a ground wire is NOT a thin wire. It is of substantial thickness so that in the event of a fault it can handle the current through to ground without burning up.

I suggest you do not do anything yourself. Get your landlord to do something; you may be able to convince them on the grounds (that word again!) that as it stands it is unsafe.

 

[Speedskater]

GFCI wall outlets are designed for human safety (there are some other GFI's designed to protect equipment, but I doubt that many of us have ever seen one). GFCI don't require the safety ground wire to operate correctly, but if only two wires are used then a label to that effect is needed on the GFCI. Some surge suppressors or EMI/RFI filters do need the safety ground wire for greatest effectiveness. But the safety ground wire needs to follow the same path and be in close proximity to the hot and neutral conductors.

 

[wings]

Grounding

You might try running a wire for grounding to a Cold water pipe, or if there is 'earth/dirt' outside your apt. window and not just concrete below, a grounding stake.

Usually the kitchen oven will be grounded even if nothing else is.