New home electrical

I need some advice on our house, and I know there are some smart electrical guys here. New home construction. My wife was ironing in the upstairs hallway and the three lights in the hall dimmed and glowed as the iron heated up. Same thing happened in my garage when I turn on my table saw-I ran 2 direct runs of 10ga wire to the workshop-that problem is solved. I have never experienced the lights dimming when an iron is used. I lived in a house that was 30 years old and never had this kind problem with the “old” wire. Many of the new neighbors say they have similar issues with their electrical. The electrical sub says it is normal and to be expected-they used 14 ga wire except for the baths and a few other circuits. Could this be a connection issue at the panel? Are there safety concerns with the dimming? (The electrical contractor says not to worry.)

It is just effects of an added load to that circuit. Solution is run a separate cicuit for the iron.

I have seen this problem on ranch homes with long home runs, I usually spec #12 for the home run, then #14 within rooms for 15 amp circuits.

I see a lot of homes with 14ga wire now. So yes, the iron will dim the lights as the circuit gets near 15 amps.

Possibly an open neutral with a chance that neutral current is being returned on the ground system.
There needs to be somebody with a multimeter and an ammeter that knows where to check.
You know it's a serious problem when somebody lifts a ground wire somewhere or connects a ground wire . And either changes the voltage on circuits.

An iron, like many resistance heating devices, draws substantial current which can cause voltage drop, especially on a 15 amp 14 Gauge wire long run circuit. If a separate dedicated 20 amp 12 gauge wire branch circuit were ran to the iron receptacle that could help the problem.

Other problems like loose resistive wiring connections, hots or neutrals, could cause the problem.

Whats needed is NOT YT Mag lay or even professional in the dark guesses/advice, but a qualified professional electrician with volt and amp meter THERE ON THE LOCATION to find the problem.

John T

The bad part of using #12 from the panel and then feeding #14, is sometime later someone will install a 20 amp breaker think whole circuit is #12.

joe

My house was wired with 14 ga, which is code for a regular 15 amp circuit. That being said whether the lights dim a bit when you use the iron has a lot to do with where each circuit draws power (ie what breaker they pull off of). In my house it was wired with what I would call a zone approach. In other words each room tends to draw power off one or two breakers for everything. The result is the lights in my bedroom tend to dim a bit when an iron is used on one of the receptacles in that zone.

Sounds like the electrician you talked to has seen, and probably done, the same type of wiring design, so if he says it"s not a problem, I really wouldn"t worry about it.

Get a tester or something (a lamp) to plug into the circuit the iron is plugged into, and any other circuits you've noticed dimming. Turn off the breaker or breakers, test each outlet until you find every outlet on that circuit. Then with the breaker off, pull each receplical out and look at the wiring on the back. Chances are the wires were just pushed into the holes in back of the receptical, you'll probably find a neutral (the white wire) that's been hot. The best solution is to rewire the recepticals under the screws if they are not already wired that way.

Caution! Many times houses are wired with "shared neutrals", where one neutral serves 2 circuits. If you break the neutral, and the other breaker is still on, power will feed back through the open neutral. Best to check each neutral to the ground wire as you disconnect them just to be safe.

Iron draws up to 1200 watts. Your wife's blow dryer draws up to 1500 watts. You have a problem but it's going to take an electrician without a dog in the fight to find it.

When I built my house I only used #12 wire and lots of home runs. Never had a problem with irons or anything else. I think it a smart investment to put money in the infrastructure, you can always upgrade the paint and tile and etc. Harder to upgrade the framing, foundation, wiring, plumbing, etc. once it's covered up.

While I can't quantify dim until they glow . That sounds like about 80 volts. #14 wire is acceptable for runs with 1500W loads up to 100 ft with just 3% drop.
Those saying this amount of dimming to a glow is normal should be ignored .
As for your electrical contractor , they blotched the job by putting receptacles on lighting circuits.
Any decent electrician keeps all the lights on dedicated circuits with nothing else. That way there is no dimming when something is plugged in. The primary advantage is when somebody overloads a receptacle and trips a breaker. The occupants are not staggering around in the dark.
Offhand I would say your electrician deserves a good swift kick in your place of choosing the next time you see him.

Any decent electrician keeps all the lights on dedicated circuits with nothing else.





Agreed. Even amatures that have limited skill and knowledge usually follow that rule.

X2

Yeah, I was going to keep my mouth shut but you nailed exactly why that is bad practice.

B&D, 99% of residential wiring has outlets on same circuit as lighting for a room.

(quoted from post at 13:06:27 08/18/15) B&D, 99% of residential wiring has outlets on same circuit as lighting for a room.

Click to expand...

99% of slob installations does not make it right .

I think most contractors I have encountered keep those circuiots of receptacles and lighting separated.It certainly is in commercial /industrial where the lighting is 277 v. Then again there was a time when residential contractors used quality metal boxes, which now you can't afford to compete with plastic junk.

Yeah, and its a lot of fun cramming two or sometimes three #12s back into the box with big enough wire nuts, huh? I did/do all my work with #12 but these old fingers sure complain. Metal boxes too but green screws and the extra jumper wire sure speeds things up. Leo the sarcastic

I agree with you that most do wire that way, however the best and most conscientious electrician I ever worked with would not hesitate to put lights and plugs on the same circuit. At the same time another electrician I worked with insisted on it at all times, but i watched him use a ground wire as a neutral in a new multi million dollar house. That being said I know which one I would rather have wire my house. If it were a safety issue it would be addressed in the code book which it is not therefore it is just a matter of opinion.
John T also nailed it when he said only the electrician standing there with the right tools can diagnose it properly
I personally would consider where the outlet is located before I blame the person doing the work. There could be many reasons why it is on the same circuit, for example when arc fault breakers were just beginning to be required in bedrooms my boss insisted we put lights and plugs on the same breaker to save buying an extra $50 breaker. Another place that comes to mind is an outlet in a closet, no real reason to have one in there but I am regularly asked to put them in "just in case" and that is one that could easily be used for an iron.

That shouldn't be normal.

I don't think I'd want to trust an electrician that tells me it is to sort it out.....

Undersized wires, or something not tight.

Paul

Yea, 14ga wire causes a lot of problems. I only use it for lighting. All my outlets are wired with at least 12ga wire. I think in your case it's more of a nuisance than a hazard. I think your only recourse is to upgrade the wiring.

Looks like another case of to get it done right you have to do it yourself. I have built a barn and two additions onto houses doing everything myself. I don't recall how I learned the right way to do it, but I made sure that I didn't skimp. Most outlets were on 20A circuits, with very few lights with them. I could have used a lot less wire, if I did it to code minimums, but I guess I had friends telling me the right way as opposed to the minimum to meet code. I also split lights and outlets in rooms so that a tripped breaker wouldn't leave you in the dark. I split outlets that were switch controlled so that only half of the outlet was switched. I suppose it comes from hiring the cheapest contractor. In my small town long time residents know what builders skimp and which ones build what they would want to own. I have known of some home owners who down the road had to live with the results of poor workmanship long after the warm feeling of a low price was gone.

I always suggest to friends/coworkers who are doing their own work or having a "friend" do it to pull the permit for the job and get it inspected as required. Being new construction, I would assume this wiring job was to code and inspected, thus pointing to a failure since then, but it never hurts to ask the local inspector. S/he may have insight or leverage to help get the issue resolved. Or not. Code is just the minimum.

When we were remodeling, I plumbed the basement bathroom drains so as to expedite the new basement floor pour. The inspector informed me that I needed to increase the size of the sink drain to 2 inches since it would be under the concrete, something I did not know. Much easier to fix then.

Man, how could I have missed the best response possible:

"Rewiring, huh? You gonna go 220?"

"220, 221, whatever it takes"


(Mr. Mom)

As always, Legal or Electrical questions draw the most opinions of any other topics lol. Everybody including yours truly crawls out of the woodwork with opinions about how to do things, including Billy Bob and Bubba who wired their shop while downing a case of beer and by golly it works fine HOW CAN YOU ARGUE WITH THAT ???????????

Regarding a few comments I saw below, in my many years as an Electrical Power Distribution Engineer, I NEVER PUT LIGHTS AND CONVENIENCE RECEPTACLES ON THE SAME BRANCH CIRCUIT. If I was working with a convenience outlet branch circuit, THE LAST THING I WANT IS FOR THE LIGHTS TO GO OUT OR THERE BE NO LIGHTS WHEN IM ON THE FLOOR IN THE DARK WORKING AN OUTLET. If an outlet load trips a breaker (MUCH more common then a light tripping it) I don't want the lights going out also.

Of course, Billy Bob and Bubba or even professional electricians are free to wire however they please (in accordance with or NOT in accordance with NEC), no argument from me. Its just NOT how I was taught or how I practiced, but yall do as you like.

My standard practice on convenience outlet branch circuits was to use 12 Gauge Wire, 20 amp rated receptacles, and of course protected with a 20 amp overcurrent protection device. On a lighting ONLY branch circuit where the max continuous load never exceeded say 11 or 12 amps, I "might" consider use of a 15 amp 14 gauge wire circuit.

Loose burned resistive connections, Neutral or Hot, too small wire, excess length of runs,,,,,,,,,,low input voltage,,, can all contribute to voltage drop and problems such as dim lights

Keep safe yall and dont work in the dark now

John T