Need help with house electrical problem.

We moved to a house that was built in the 50's. All of the plugins, except a couple, are the 2 prong with no ground. I tried charging my SL20XP, and when I use 2 prong plugins, the charge light comes on full bright, then gradually dims to nothing. The 3 prong 6 gang add on boxes don't do this, they work fine. If I just barely plug the light in where the prongs just make initial contact the light charger works fine.
I then took a volt meter and checked the current. It is at 112 volts. I then plugged the AC light adapter into the socket, and checked the 12 volts at the charging head. It registers 12 volts then the needle on the voltmeter steadily drops to 0. As I said there are 2 places in the house where there has been added a 6 gang, 3 prong plug, and the light charges fine in these.

Does it sound like replacing the pluggin box with a newer one will fix it? Am I going to need to ground these plugs? Or do I need to get an electrician in to check the system?

Thanks for any help

Bravo,

Sounds like you may have a intermittent electrical outlet... Over the years, the inside spring fingers can lose tension and may only make connection when the plug is first inserted. Especially if the (male) prongs on the plugs are solid (vs those that are two piece prongs that you can take a knife and spread apart).

I would try replacing the outlet, or for a quick test, use an extension cord plugged into the wall. You can then test the extension cord output with a table lamp and your charger--and see if you see consistent results. I believe the charging light slowly going out is just the surface charge on the capacitors being bled-off after an initial hit of 110 VAC.

At your local electrical/home center, you can find different grades of electrical outlets--I usually go one or two grades up to make sure that my outlets don't wear out too quickly.

In my parent's old home (about the same age), I found that the outlet box was grounded via a smaller gauge wire (something like 16-18 gauge). So--you should be able install a three prong grounded outlet without problems.

You can do a quick check with a meter or 110 VAC test light. The narrow blade is hot, the wide blade is neutral, the center mounting screw (cover mount) should be ground. You will measure 110 VAC between hot and neutral, and hot and ground. You should see between 0 and a couple volts between ground and neutral. Using a light (even a couple watt night light) may be better than using a high impedance digital meter (hard to tell if you have a "real" round or not unless you pull some current).

Regarding Grounding: I have seen some equipment that won't work correctly if it does not have a proper ground connection--but this was typically for uninterruptible power supplies ( such as UPS's for computers)--and it tested for a good ground. If your charger has only two blades, then grounding should not be an issue. If you have surge protectors plugged into an outlet with poor or no ground--then your down stream electronic equipment is much less protected against power surges. Your choice on playing the odds here as to whether or not you would want to ground or not (price of your electronics/data typically).

One other issue to watch for in older homes are for weak neutral connections (corroded or poor connections). Typically, you would see these when a heavy load on one circuit (washer, microwave, etc.) turns on, you notice tungsten lights on another circuit become significantly brighter (like they may burnout). Think of a center tapped transformer the outside two legs are your 110 VAC (220 VAC across them) and your neutral is the center tap. If the neutral breaks (example) then you have your motor and light (example) directly across 220 VAC--a good way to blow your expensive electronics.

Last issue is aluminum house wiring--if you had no major electrical work done in the 1960's, then you probably either have copper wiring or, at least, electrical outlets designed to work with aluminum wire (late 60's into the 70's???). History of failing connections (and sometimes fires) when using aluminum wire with connections designed for copper.

Hope I was clear--if you have any questions, let me know.

-Bill

Bill I must say I appreciate your knowledgable and detailed posts. You must have quite a varried line of interests to have, good, detailed info in such a variety of subjects. I've noticed several of our posts over the last week or so. Have you just started posting more? And a sincere thanks for the posts I've noticed. /ubbthreads/images/graemlins/thumbsup.gif

Is 112 volts normal these day?

[ QUOTE ]
eluminator said:
Is 112 volts normal these day?

[/ QUOTE ]

I believe 110 to 117 is considered normal
Bill thanks for the reply. I'll post my findings.

I've been going around this house and replacing all the electrical outlets a few at a time whenever I have a chance. As is typical of construction they are the cheapest kind you can buy and installed in the cheapest, fastest manner. Which is passed through the receptacles using the backstabbed connections.

When you get new outlets blow the extra buck a piece at the hardware store and get the ones with "backfed" instead of "backstabbed" connections. These are relatively new, but are almost as easy to install as the backstabbed ones but they are still reliable under load and last as long and are safe as the screw terminals. You can tell the difference easily enough, if the wires are pushed into holes in the back and you have to stick a nail or small screwdriver into some release slot then they are the evil backstabbed connection. The BackFed outlets use the screw to pull a clamp down on the wire.

a voltage reading of 112 should be no problem, but what kind of service does the house have? Do you have a fusebox or breakers? is 220 available? Your house was built before the aluminum wiring came into widespread use in the early 70's, but if the electrical system was updated or added to in that time frame you might have a mixture of aluminum branch wiring and copper, which is potentially very dangerous, and the bad connections that causes could definitely cause intermittent, or lower voltage connections as it heats up in other places along the run. So definitely keep an eye out for that as you replace that outlet. (it's always aluminum that feeds the service box and breaker panel, so if you see aluminum wire as the big wire coming into the breaker or fusebox thats OK, it's only aluminum wire leaving going out to the rest of your house that is a problem.)

Voltage...

Around here the elec company has 120 volts plus or minus 10 percent. So 108 to 132 volts is ok. They usually shoot for 120 though.

Just took a car load over to the house, and while there I checked the wall sockets with a lamp. They all work fine. Just not with the SL charger. Strange!

Did you try an extension cord to the SL charger (and wall lamp)? I have seen geometry issues between different plugs where one works pretty reliably, and another does not in an old outlet. Thus the recommendation to use an extension cord to see if wall outlet is just intermittent with your SL charger.

Also, it is possible that the SL charger has an intermittent connection--again, playing with it on the end of an extension cord can help isolate wrt to the wall outlet.

I would still suggest replacing the old wall outlet (check with meter that power is off, both hot to neutral, neutral to ground, and hot to ground--I have seen older homes/garages where somebody messed up and put a breaker on the neutral or reversed hot/neutral connections)--they are pretty cheap. Also, when you take the outlet out, make sure that the wire is copper (scratch with a knife). If it is aluminum, make sure that the replacement outlet is Aluminum rated (I think they make a connection grease for aluminum too which helps prevent connection failures). (FYI--failure is, aluminum expands with heat, extrudes out, then contracts when cool, forms oxide on contact surface exposed to air, next load causes more heat because of higher resistance, extrudes more, cools, more oxide, more heat on next load, etc., until high enough resistance for failure or even fire--Aluminum rated connections, as I remember, withstand the expansion/contraction cycle better and prevent oxide formation).

And with old wiring, try not to flex it too much--the insulation can be pretty brittle (especially in overhead lighting fixtures where heat from lamp speeds aging).

Bravo and Wits' End, thanks for the Kudos'... I sometimes post more or less, depends on what is going on in CPF and home--I have read CPF for a long time before registering (back when the member numbers were around 600). I enjoy both technology and politics--but I do try and resist /ubbthreads/images/graemlins/wink.gif turning CPF into a political forum. Very few people want their minds changed--most (and I can fall into this trap too) want to convert others to our way of thinking. For myself, I try to keep discussions more towards facts, cause and effect, root cause, etc. (my engineering background--I may need to convert people to my design concept, looking at possible pluses and minuses of the design, etc. But when something is broken, it does not matter what I think is wrong, only what is wrong, and you need to gather facts and opinions to make that determination). It can be frustrating debating whether or not X is more right than Y in a vacuum. But if X causes Z and Y does something else, then people can have a more fact based discussion on what works or not. That is why you see me posting more when facts need to be corrected or supplied in discussions--my very own pet peeve.

Back to Bravo's wiring discussions.

Take care,
Bill

You can get copper entrance cable if you look hard enough. Electricians know where to get it because that's what they use in their own homes.

I think whether your local electrical store stocks copper or not depends on the price of copper that day, which depends on whether the copper miners in Chile are on strike that day.

At least that's the way it used to be.