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Electrical Wiring in the Home/Sparks flying from extension cord


QUESTION: This is probably not the typical type of question you get, but I'm not sure whom to ask. My son is very into electricity and owns numerous extension cords and power strips. He recently ran a "circuit" in a big loop around the house. Basically, he piggybacked a couple of extension cords, then surge protectors running from his room, around the house, and back to his room to bring power to some Christmas lights. Today, the lights suddenly started to flicker. One of the extension cords has a clear female (3 outlet) end and, where the subsequent cord was plugged in to it, we saw sparks. Of course, we unplugged everything immediately. The cord, itself, is in good shape and I suspect that the issue was caused by water intrusion - the connection was right by the toekick under the sink (yes, stupid in hindsight). Is that the likely issue or is it possible that the issue was caused by the piggybacking (this was the third connection in the circuit)? Do we need to throw the cord away altogether? Obviously, if we hadn't been home and observing the lights, this could have been a real disaster.

Thanks for your time!

ANSWER: Claire,

Its possible the connection at that point under the sink may have gotten water in it if you have leaky pipes under there but its probably more likely a compromised (loose) connection between plug and receptacle caused it.

Extension cords connected to other extension cords and power strips is indeed a formula for disaster in terms of fire and shock hazzard especially when a novice is doing it. It would be in the best interest of everyones safety to curtail your sons experimenting in this area without suppressing his interest and enthusiasm of course. If he's of working age maybe let him work for a local electrician as a helper.


---------- FOLLOW-UP ----------

QUESTION: Thanks Bob!

Can I trouble you with one more question? I've been trying to understand the danger in piggybacking when the final load is small wattage (usually a strand or two of Christmas lights). What is the inherent risk? Is there a risk if there is no load at the end?

My son is very careful and is good about avoiding risk when the rationale is explained, so I'd like to better understand it. Of course, I do understand when you're trying to power numerous loads at once with a circuit that can't support it, but I feel there are larger issues that I fail to understand.

Many thanks,


First off I have to say I can't recomend piggy backing multiple extension cords because its just not safe to do wether its inside the house or outside. For example
you don't want to piggy back two 50' 16 gauge ext cords to serve an 8 amp load.
Better to have a 100' 12 gauge ext cord.

If the load is small compared to the ratings of the wires below then the risk of trouble tends to go down generally speaking. Its when you start "loading up" that connection points could begin to get hot if the connection is poor between receptacle and plug. The more connections you have the more potential trouble. Its important that plug and receptacle are making good contact. How can you tell ? If you pick the two of them up and they are cool to the touch then your fine. When you start "loading up" that could change to slightly warm which is OK. Its when it gets between warm and hot that you have to watch out. Trouble could be brewing and this is why you want to avoid piggy backing multiple extension cords.

If its outside make sure your plugging into a GFI receptacle.

16 gauge 10 amps

14 gauge 15 amps

12 gauge 20 amps

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"The Frank Williams School of Electrical Construction". My dear old boss is 100 ! and still going God Bless him. I started working for "Tenafly Electric" right out of high school at 19. He was tough but I learned more working for him in 8 and half years than most guys. We did mostly industrial work while doing some commercial and residential so I was fortunate to be exposed to all 3 areas of electrical construction. The guys I worked with were all good guys and I stay in touch with some of them still. Most of us went into our own buisness's which says something about the caliber of the guys I worked with. We had some interesting clients : Wella Corp. of shampoo fame, Farah Fawcett etc, I didn't buy shampoo for 10 years. It was a great place to work. Pan Am the former airline just before they went under, another great place to work, nice clean environment. C&C Metals, the largest button manufacturer in the US at that time, a not so clean environment but a very interesting place to work, lots of machine's cranking out buttons of all kinds but you had to be on your toes, it was a potentially dangerous place to be . All kinds of action going on around you.

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