1960 electrical

Originally Posted By: sseymore
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I just started doing home inspections this year and have mainly done newer homes. Yesturday I inspected an apartment complex built in the 60’s. The outlets were all the older two prong outlets. And on the electric panels many had double tapped onto the main service entrance.

Question number one that I have. 1. Can these older outlets be switched out easy to become correctly grounded? 2. What is the main problem of tapping into the main service entrace? I would really appreciate anyones help thank you for your time and help, Sean

Originally Posted By: gbeaumont
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Hi Sean,

1. it is normaly difficult to connect a grounding conductor when the home was originally wired as only a 2 wire, but it depends on the wire and conduit types.

2. Any circuit? tapped onto the lugs potentialy has no means of disconnect over and above the issue of improper connections.



Gerry Beaumont
NACHI Education Committee
e-mail : education@nachi.org
NACHI phone 484-429-5466

Inspection Depot Education

"Education is a journey, not a destination"

Originally Posted By: pabernathy
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OK....I will give a little education forum for you so you are armed with the information you need when you see this again and what you can tell the owner.

1.) 2-hole is ok as long as they leave it as such...sure it is not grounded so you need to make the client aware of this. If they intend to replace this they can do so WITH another non-grounded 2 hole recept. only. Review NEC Art 210-7d3a in 1999 NEC and Art. 406-3d3a in 2002 NEC.

2.) If they would like to protect themselves better while having non-grounded system, they can choose to replace the recepts. with a GFCI recept. or they can replace the entire circuit with a GFCI breaker and label each recept. " GFCI Protected" and " No-Equipment Ground" This will raise awareness as well as add some level of protection....still provides no ground so do not confuse it as such....this is only a protection solution not a grounding solution. ( 1999 NEC Art 210-7d3c- 2002 NEC art 406-3D3c

OK...the client wants it grounded...what are their options......well personally I think it oversteps the boundaries of the HI to go into this other than explaining it because we all know the home owners and their quick fixes.

1.) a.)They can provide a seperate EGC from the box itself ( if metal ) to the GEC or any accessible point on the grounding electrode system as described in section 250-50 b.) Any access point on the grounding electrode conductor c.) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit orginates.

Now...of those grounded and non-grounded systems....

Grounded Systems-, the grounded service conductor within the service equipment enclosure.

Ungrounded Systems -, the grounding terminal bar within the service equipment enclosure.

So in short....the above methods to achieve a ground for the recept in question can get complicated and I would simply recommend that this point if they have an interest in the creation of a grounded system from exisitng wiring they should consult a licensed electrician for their options.

Most all homes built before 1962 will not have 3-hole recepts in all locations. Just know that if the client is concerned they do have the option for protection of using a GFCI breaker ( provided the old panel they have will accept one...thats important ) otherwise they will need a GFCI recept. in the first recept of the branch circuit to which it is designed to protect.

Their are a few more issues with GFCI's remaining GFCI's and so on as well as grounding types and replacement of a 3 hole recept. must be done with another 3 hole recept. and all that jazz but will not be relavant to older homes as in your question.

Hope this explains it some....

On the issue of double tapping......well honestly the issue is more of a issue if the tap is of the main and the wire tapping the main is not sized correctly for what it is being tapped for....tapping in itself is allowed in some cases and it was the nature of split panels and so on....but the biggest concern a HI needs to focus on in tapping of a main is the following...

1.) What is the tapping for....?
2.) Is the tapping an approved method for tapping..(Not curling a wire around a terminal and calling that a tap)
3.) Is the OCPD that is protecting the wire that is doing the tapping sized correctly for the size wire...ie: a # 6 AWG tapped onto a main lug to supply a sub-panel below with a 100A OCPD main.......the actual wire is under rated and a possible hazzard...these are things HI's really need to focus on more than just is their a tap....

Now jaming a wire into a main lug is obviously not allowed...the connection is not approved probably for multiple wires in it and would be a problem as explain before....but I tend to focus more on the size of the wire that is tapping and the method of the tap itself.....and the protection to the wire via the OCPD that is connected to the load side of that TAP.

Tapping of a breaker itself is considered wrong in many standards...now the fix in the old days by some EC was to remove the double connections to the breaker and wirenut them together with a pigtail to the breaker giving only one connection to the breaker....

This does put possibly more recepts and draw on the breaker but the rating of the breaker should be as such that it will trip when the capacity exceeds the 80% rating of the breaker itself so thus still protecting the wires....so the world does view double taps as wrong and they should as it is usally a sign of a possible undersized service and care needs to be taken to review the loads in question...BUT not by a HI...always refer this to a licensed electrician for review....

I prefer the method of saying...ok Mr. Homeowner ( this is as the electrician they call out...not the HI )...if the HI has a concern about the double tapping...give me a bit of history on your house and ask about tripping breakers and so on...( do I expect them to be totally honest...nope...) so I walk off the square footage, make a note of possible loads other than general lighting...and in most homes that are old...it is easy to calculate...trust me most electricians can do this....

Then and only then can I make a suggestion....but in many cases the system was 100A and under spaced in todays standards..for example we see alot of 100 - 20 and 24 ckt panels...while older 100A panels were 16-18 and some maybe 20....so in many cases over the years only 2-4 circuits were added and usually small ones 15A or 20A...and have been running fine...we AMP probe it.....turn on some of the major appliances and so on...take a few readings and in some cases give these options...

1.) I do not or cant justify a new service.....you simply have no modern day continuous load...if you plan to upgrade the house, build on or renovate you need to bring it up to a 200A....but I can't tell you to do that unless it is obvious....

2.) to eliminate the double tap issue....the solution may be as simple as tandom breakers ( if allowed ) or piggy backs in some older SQ D models....

The point is most panels are rated for that they have...a 100A 18 ckt panel is designed for 18 ckts....so lets say their is (2) double tapped..so you need 20 ckts....I will not justify a upgrade...the NEC does not mandate it as this home may be older...however my intent is safety and offering the protection of the above methods may bring that.

In the end...each panel is different and you have to use judgments and caculations...heck maybe a sub-panel will assist here and move 6 circuits over and free up space for a breaker to feed the sub...who knows..but again this is not a HI's call.....in the end refer it to the electrician.

Paul W. Abernathy- NACHI Certified
Electrical Service Specialists
Licensed Master Electrician
Electrical Contractor
President of NACHI Central Virginia Chapter
NEC Instructor
Moderator @ Doityourself.com
Visit our website- www.electrical-ess.com

Originally Posted By: wdecker
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That is one of the good things about conduit. No problem with changing 2 prong to 3 prong grounded. Almost all the time, the conduit is ground bonded.


Will Decker
Decker Home Services
Skokie, IL 60076