Advice on 2-wire system?

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#1

Originally Posted By: HyperEye
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My wife and I are buying a house. We are actually scheduled to close in 2 hours! Yesterday the electric company informed us that all of the house (except the garage) is wired 2-wire copper. I am pretty concerned about this. I have a lot of computer equipment, expensive television, etc.


Is there something I can do to protect this equipment without rewiring the house? Is it pretty imperitive that I have this wiring replaced?

I am asking this because I do not want to rewire if I can avoid it. If I do need to rewire I need to put off closing until I can get an estimate on what it will cost. If anyone can help I would appreciate it.

#2

Originally Posted By: HyperEye
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Well, it is getting to close. I put off closing. I hate to do it but this is really worrying me.

#3

Originally Posted By: phinsperger
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ground. Computer equipment esp “should” be pluged into grounded outlets as there are small static discharges that are sent to ground. I have seen computers plugged into undgrounded outlets for months with no apparent side effects.


If you want to avoid rewireing, the other option is to run a separate ground wire. Personally I would do the rewire as it is not that much more work than running a separate ground wire and will look better when you resell your house. Also some of the insulation may or may not be deteriorating from the old ungrounded cable.

--
.


Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
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#4

Originally Posted By: jpeck
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Depends on how you want to protect it.


First, I would be more concerned about protecting the people in the house, and that would mean installing GFCI receptacle outlets to protect all receptacles.

Then, I'd be more worried about protecting the house from fire, protecting you equipment in that way. This would be by installing AFCI on every circuit. However, if you have a fuse panel, you will need to replace the panel.

Lastly, you may want to re-wire the house for the above reasons, but at the very least, have an electrical contractor check the insulation on the conductors by doing a hi-pot (high potential) test. With two wire circuits, many of those were wired with conductors with rubber insulation, which deteriorates over time. The hi-pot check will hopefully (but not guaranteed) find any bad insulation. Hi-pot tests are like cancer tests, you might get a false negative (no cancer and no problem) because it depends on what and how the test is performed, but you don't get a false positive (cancer or failed insulation). If the test is positive for a problem, you have a problem. In which case re-wiring would be the best solution.

--
Jerry Peck
South Florida

#5

Originally Posted By: rpalac
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I agree with phinsperber.Unfortunatly your cutting it close and might have already signed off on this item.


The best I can tell you is have a couple of GOOD qualified electrician give you there estimate. Ask them if it does have ground wires in the existing cables that just need to be grounded or connected if your lucky.

On this end it is difficult to tell without seeing it.

You should have had the house inspected first!

Bob P.

#6

Originally Posted By: HyperEye
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The house was inspected icon_smile.gif

#7

Originally Posted By: rpalac
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Wasn’t this commented on previously?


is it knob & tube,


romex


BX


I'm suprised it's down to the zero hour. This is a tough situation.

#8

Originally Posted By: HyperEye
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It was not mentioned in the report that the house is run 2-wire. It does mention that the GFCI outlets tested 2-wire except the kitchen which tested poor ground. A ground wire was found in the crawlspace under the kitchen and the report says:


Quote:
Under the kitchen there were ground wires installed but they are simple twist connections wrapped around the water pipes and corrosion is present. It appears that this ground is not very positive/secure. I recommend having these wires properly clamped and routed to a better ground connection.


There are other places in the report where 2-wire is mentioned such as

Quote:
Rear porch - Wall Outlet: This outlet is wired only 2-wire and is rusted. The wire to it appears to have been chewed on. I recommend removing this outlet. You could replace it with a properly wired/GFCI protected outlet.


That outlet was removed yesterday. The only other time it is mentioned that I can see:

Quote:
Laundry - Waching machine outlet: This plug tested 2-wire and not grounded. I recommend updating this outlet to 3-wire properly grounded.


Here is what he said about the houses electrical:

Quote:
2) Main electrical service - This house has 200-amp service with the main cutoff located inside the garage breaker panel.


And that's that.
#9

Originally Posted By: HyperEye
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I am wondering what you guys might think about this. I am considering the idea of using a ground rod. I thought I could possibly run ground wires from the rod to any outlsets I want grounded (outlets with equipment, etc.) For the rest of the outlets I could use GFCI protected outlets. Does this sound like a viable solution?

#10

Originally Posted By: jpeck
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HyperEye wrote:
I am wondering what you guys might think about this. I am considering the idea of using a ground rod. I thought I could possibly run ground wires from the rod to any outlsets I want grounded (outlets with equipment, etc.) For the rest of the outlets I could use GFCI protected outlets. Does this sound like a viable solution?


Ground rod? NOT unless you are tying everything back to the main electrical system ground.

If you drive a separate ground rod for your equipment you will likely cause all kinds of ground problems with ground loops.

That would (could) be a nightmare to correct.

If it's on a crawlspace, just rewire from the bottom.

--
Jerry Peck
South Florida
#11

Originally Posted By: jhagarty
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It would be best if you contacted a Licensed Electrician for advice and to obtain estimations regarding upgrades and repairs.

–
Joseph Hagarty


HouseMaster / Main Line, PA
joseph.hagarty@housemaster.com
www.householdinspector.com

Phone: 610-399-9864
Fax : 610-399-9865

HouseMaster. Home inspections. Done right.
#12

Originally Posted By: jfarsetta
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I agree “Hypereye”. It’s best you hire an electrician for further evaluation and a plan of attack.


BTW... what kind of name is hypereye? Since we dont know who you are, or where you come from, you could have used your real name, as most others seeking some information do.

I'm curious as to what the inspector meant by "chewed on"...

--
Joe Farsetta

Illigitimi Non Carborundum
"Dont let the bastards grind you down..."

#13

Originally Posted By: HyperEye
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I signed on with my real name but changed it afterwards. I do not like to use my real name on the net and I am known on quite a lot of forums, websites, in IRC, all over the place on the net as HyperEye or Hyper_Eye. It just sits better with me. I have been using forums, irc, IM’s and such for a long time and I find that not using my real name is always best. You never know.

#14

Originally Posted By: jhagarty
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HyperEye wrote:
... the electric company informed us that all of the house (except the garage) is wired 2-wire copper.


Why was the Electric Utility company inspecting the interior wiring of the home?

How old is the home?

--
Joseph Hagarty

HouseMaster / Main Line, PA
joseph.hagarty@housemaster.com
www.householdinspector.com

Phone: 610-399-9864
Fax : 610-399-9865

HouseMaster. Home inspections. Done right.
#15

Originally Posted By: phinsperger
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jpeck wrote:
If you drive a separate ground rod for your equipment you will likely cause all kinds of ground problems with ground loops.


Jerry,

How does this differ from isolated ground (orange outlets) found in commercial builings for their sensitive equipment?

--
.


Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
Place your Award Nominations
here !
#16

Originally Posted By: jfarsetta
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It is obvious to me that there may be more gouing on here than meets the “hyper” eye…

–
Joe Farsetta


Illigitimi Non Carborundum
"Dont let the bastards grind you down..."
#17

Originally Posted By: jpeck
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phinsperger wrote:
jpeck wrote:
If you drive a separate ground rod for your equipment you will likely cause all kinds of ground problems with ground loops.


Jerry,

How does this differ from isolated ground (orange outlets) found in commercial builings for their sensitive equipment?


Paul,

The isolated ground receptacles still have the ground for the receptacle taken back to the main system grounding point.

Typically, the raceway is not used as the equipment ground path and the isolated equipment ground conductor is run back to the service equipment ground point without being connected with other equipment grounding conductors.

Driving a separate ground rod (as I believe was being proposed) over by the location of his equipment would create a second earth ground point, and the two earth ground points would not be tied together, resulting in voltages, electrical noise, etc. being generated between the two earth ground points.

(D) Isolated Receptacles. Where required for the reduction of electrical noise (electromagnetic interference) on the grounding circuit, a receptacle in which the grounding terminal is purposely insulated from the receptacle mounting means shall be permitted. The receptacle grounding terminal shall be grounded by an insulated equipment grounding conductor run with the circuit conductors. This grounding conductor shall be permitted to pass through one or more panelboards without connection to the panelboard grounding terminal as permitted in 408.20, Exception, so as to terminate within the same building or structure directly at an equipment grounding conductor terminal of the applicable derived system or service.
FPN: Use of an isolated equipment grounding conductor does not relieve the requirement for grounding the raceway system and outlet box.

--
Jerry Peck
South Florida
#18

Originally Posted By: HyperEye
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jhagarty wrote:
HyperEye wrote:
... the electric company informed us that all of the house (except the garage) is wired 2-wire copper.


Why was the Electric Utility company inspecting the interior wiring of the home?

How old is the home?


The home was built in the 60's. The electric company was there because they had fixed some issues for the seller. When I had the house inspected some of the issues they had "fixed" showed up on the inspection as not being fixed at all. For that reason they were sent out to the house to fix those issues as well as the other issues pointed out in the inspection. They informed me of the 2-wire not grounded system because they wanted to let me know that the GFCI outlets were not grounded.
#19

Originally Posted By: phinsperger
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Good explanation Jerry thanks icon_smile.gif

–
.



Paul Hinsperger
Hinsperger Inspection Services
Chairman - NACHI Awards Committee
Place your Award Nominations
here !
#20

Originally Posted By: jfarsetta
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Jerry,


Nice post. There are other approved methodologies for providing isolated grounds in commercoial applications, such as tying it to the neutral of an isolating transformer, providing that a dedicated conductor runs (from that neutral) directly to the ground referenced by the building switch gear. The transformer neutral can also tie to building steel (CAD welded straps)in some instances, providing that the steel is also tied to the same grid as the main serving transformers.

The key point of your explanation goes to the isolated bus bar in the serving panel. This is a dedicated bus, and not associated with the regular panel neutral or ground bus.

This type of system has sometimes been referred to as a single-point ground. Absent of this configuration, and especially where another ground source is referenced (as with a separate ground rod) will most likely cause some ground loops.

As to this discussion, however, your explanation is direct and most correct. Good job.

--
Joe Farsetta

Illigitimi Non Carborundum
"Dont let the bastards grind you down..."