No ground in old building


#1

I live in a 100 year old building in San Francisco and the circuit I use for my stereo doesn’t seem to be grounded. I used one of those things that you plug into the outlet and it has three lights to tell you what’s going on. It says “open ground”.

I currently have a Dectet but I’m looking for a used PowerPlant P3 or P5.

Will it still work correctly?


#2

So your tester has given you an unsafe indication, right? If so this needs to be reported to the building owner for rectification.


#3

Yes, no problem. While a ground is good to have it isn’t necessary for the operation of a Power Plant.


#4

It is possible that whoever installed the outlets didn’t connect a ground to the box, although just connecting it should have grounded it. There will either be conduit or BX running through the walls.
Do you have access to the fuse box? Are they breakers or screw in fuses?
I have to agree with Brodric, you should have an electrician out, both to inspect all of the wiring, and have him install at least three dedicated circuits. If you decide to buy a P20 you will need a 20 amp circuit with a 20 amp outlet. I would have one 15 and two 20 amp at a minimum. With at least one of the 20s back behind the speakers. For a sub or two, and if you go to monoblocks.
If you deal with a local audio dealer, ask him to recommend an electrician who understands the needs of an audio or videophile. One that will install heavier gauge wire than code requires.


#5

Ungrounded branch circuits in old homes isn’t that uncommon. Most likely very difficult, to impossible, to fix without a major renovation. It could even be old knob and tube wiring.


#6

My house is old knob and tube which means two wire system with no ground. I brought new 10 amp circuits to my stereo by running metal conduits in the garage and grounding from the main panel which is also connected to the ground rod and water pipe. You can get a electrician to bring a ground wire from a water pipe if possible, but never connect or use the neutral wire for ground. That will bring all kinds of noise to your stereo. It’s best if you can upgrade your electrical system by rewiring the whole house, otherwise just forget about the ground. Everything will work fine without ground, only you will not have the safety of if current somehow get on the chasey and you touch it, you will be the ground and get shocked.


#7

For safety you can also install GFCI receptacles.


#8

GFCI receptacles require a ground wire also to work properly, otherwise it’s no different from any other three prong outlet.


#9

@Paul and @waymanchen11 (and anyone else too!), So I have a PS Audio Soloist on what ended up being a dedicated line (nothing else I can tell is hooked into it). It is 2 wire and currently is hooked up with ground and neutral together. Now I am fine with getting into the wall and disconnecting the ground from neutral. Should I even if there is no discernible noise? Should I try and hook ground to something else in the wall, originally the outlet had the ground hooked to the metal outlet box which was removed when we put in the soloist. Also is the soloist going to work ok without the false (bootleg) ground?


#10

If there is no noise, I would not mess with it. Be aware that if you try using the neutral for ground, and have you equipment plug to this ground, you can created a ground loop into the neutral and cause a lot of noise in the circuit, It happened to me when I connect the third prong to the neutral and plug my stereo in. The noise went away when I lift the ground from the neutral and just run the stereo with open ground.


#11

Great, thanks for you response! I will leave it alone for now then unless someone thinks differently


#12

No they don’t! Hot and a neutral through a Current Transformer (CT)…if there’s a difference (100ma?), it trips.


#13

You are right, GFCI outlets can be wired without the ground wire and still work. They sense the difference in current flowing in and out of the load. It will trip if it senses more than 5 milliamps difference and do not require a ground wire to be connected. But I would use GFCI only in wet areas for protection since I have bad experience with them tripping when you don’t need them to trip. Sometimes they trip in bathroom connected to a fan and it is annoying to have to reset them all the time.


#14

Brodric’s right. A GFIO requires a ground to work.


#15

Can anything really be resolved on the internet? A little more info…

https://www.nachi.org/forum/f19/gfci-ground-31370/

https://www.quora.com/Will-a-GFCI-work-without-a-ground-wire-How

Last link, Mike Holt is a bit of a self made expert on the National Electrical Code (NEC). This is an older reference but still valid.

https://www.mikeholt.com/mojonewsarchive/All-HTML/HTML/GFCI-Receptacles-Without-Ground~19991230.php


#16

If it is an old building, it most likely will have an all metal water piping. Can these pipes be wired to and used for ground? This has been done before, but it depends on the pipe network implementation.


#17

Yes, you just need something g with an electrical connection into the Earth. Some old plumbing won’t work but often times it will.


#18

So I am thinking of attaching a 10 or 12 awg (20A circuit) insulated wire to the soloist and directly taking this 10 feet along the top of the base board and out the wall to the outside and attaching it to a 8ft grounding rod outside that I will hammer into the ground. Anyone see an issue with this? Any thoughts on pure copper vs copper plated steel rods?

Also is this better than attaching the socket from my dedicated line to a ground wire that is attached to many other sockets on another circuit? My house is old and the genius that renovated the house didn’t update the wiring in the old part even though he had all the walls open and could have updated all the two wire sockets.


#19

Yes, it’s against code. Ground (dirt) is not a good conductor. The idea is to provide a low impedance path back to the service panel. A ground rod doesn’t do this any better than no ground.


#20

Aha! Well that is good to know! So option 2 (attach to another ground wire in the house) or just leave it with no ground?