Old house, lots of toys, am I going to burn down?

September 16, 2006 1:31 PM

I live in a hundred-year old house (in Los Angeles, no less!) that has limited electrical outlets. I have unlimited (it seems) electronics - three computers, monitors, two laser printers, two air conditioners, electric heater (in the winter), etc. The house was upgraded from old-style fuses to circuit breakers a few years ago. It is a rental so I am not able to do any upgrades. None of the wall outlets are three prong, so I am using adapters. In the summer, my office is just overdone with things drawing power - all three computers, the printers, AC, and probably 20 (or more) smaller items - cell phone, postage scale, radio, etc....

Back when I had fuses, doing anything "heavy" - like turning on the microwave in my kitchen - would blow a fuse. Since then, I'm fairly sure such activity hasn't tripped a circuit breaker even once (whether this is relevant to my question, which is coming, I promise, I'm not sure.)

I try to keep my cords neat - though I don't always succeed - and the biggest items are plugged into a heavy duty UPS/surge protector (I have several of them.) But pretty much everything seems to run into the same circuit.

So, am I at risk for a fire? I try to keep as many devices switched off as I can, but during work days, things go at full tilt; in the hottest months or summer and colder months of winter, it is almost mandatory to use AC/space heater. If I am at risk, what can I do about it? I am afraid of the place burning down while I'm out. Is the hassle of turning everything off every time I come and go (as well as at night, I suppose) worth it?

thanks!

posted by soulbarn to computers & internet (12 comments total)

Sometimes old Circuit breakers can do exactly what you describe, you have the microwave and the dishwasher running, it's time to run down into the basement to reset the breaker. Now I'm not sure its the same way with old timey fuses, but if you haven't had a problem so far, you're probably alright.

What probably happened is that they upped the amperage to compensate for the fact that you have very few circuits. Probably just lazy on their part. If you look at the inside of the circuit box, all of the circuits come back to the same spot, so your weak point is going to be wiring not being able to handle the load. And since you're running circuit breakers, if you do have a problem, you'll bypass overloading any of your expensive gear.

You can check this by looking at the circuit box, and seeing which circuits go to which outlets, and seeing what their respective amperage is. If they're mostly within 20A or so, I wouldn't worry all that much, we had an old house with breakers put in, and had no problems. Except for the time we needed to replace a breaker, due to it constantly switching off. In this case it wasn't due to load, but due to the breaker itself being defective. (Once we opened the breaker box, we saw sparks, so we knew something was up.) YMMV and IANAE (Electrician) but I wouldn't worry all that much, if you haven't had a problem already.

If there are any electricians in the house, tell me that I'm wrong, so I can correct my ways. I would look into some homeowners insurance just to be safe, though, it's a good policy either way, its cheap, and if you do have a problem, it's nice to know that you're covered.
posted by gregschoen at 1:54 PM on September 16, 2006

Probably just lazy on their part.

Just to correct myself a little more, I think I meant more along the lines of far cheaper for you, since they don't need to run new wiring, which is typically expensive.
posted by gregschoen at 1:57 PM on September 16, 2006

gregschoen has it pretty much correct. I would recommend that if you do not have a circuit directory, you would be wise to make youself one by turning only one breaker on at a time and taking something portable around to the outlets, determining which feeds what. If your breaker panel is reasonably new, you shouldn't have to worry too much about the breakers protecting you and your equipment. You may want to juggle where things are plugged in to balance the load, and when you have all breakers off, it might be a good idea to open the panel and tighten the screws on the breakers. NOT THE MAIN, of course. My e-mail is in my profile, if you have any further questions.
posted by scottymac at 2:20 PM on September 16, 2006

Assuming the electrical work was done properly, the circuit breakers will protect you from overloading a circuit. I would turn off the high current devices, the AC and space heater, when I was gone to save on the power bill. Don't worry about the hot water heater. It is on a separate circuit.

Scottymac alluded to balancing your load. What he means is to try to spread your equipment around, if possible, so that it is not all on the same circuit. I wouldn't worry about all of your office and electronic equipment being on the same circuit since they don't amount to all that much. But I would try to avoid plugging the AC or space heater into that same circuit if you can. As he said, make a table or map of the circuits by turning on only one breaker at a time. Make a note of which outlets, lights and kitchen appliances work for that circuit. Using your map, you can move some things around so that different circuits share the load.

If you are the analytical type, you can add up all of the stuff on each circuit and determine the load yourself. First look at each circuit breaker. They should be labeled either 15Amp or 20Amp. Wattage is amps times volts. So for a 15 amp, 120 volt circuit, the maximum watts is 1800. For a 20 amp circuit it is 2400 watts. On the back of each appliance or piece of equipment there is a label. It will indicate either the watts or amps used by the device. If in amps, just multiply by 120 to get watts. Add up the watts for everything on the circuit. If you exceed the maximum for the circuit, it tells you that you shouldn't turn on everything at once. Keep in mind that the labels only indicate the worst case power. Most equipment doesn't use their full rated power at all times so you have some margin.

For example your toaster and microwave are probably plugged into the same circuit. Since they each use around 1200 to 1500 watts, you probably don't want to operate them at the same time. Note that most circuit breakers have a time delay built in. For example a typical 20 amp breaker will allow 30 amps for up to 3 minutes without tripping. This is okay because at that current it would take a long time to generate enough heat in 12 gauge wire to start a fire. This saves you from tripping a breaker if you turn on your toaster and microwave at the same time because the toaster will probably turn off before the breaker trips.
posted by JackFlash at 5:03 PM on September 16, 2006

By the way, if a licensed electrician installed a breaker box and didn't label the circuits, I'd be suspicious of the quality of the installation...
posted by plinth at 5:04 PM on September 16, 2006

It sounds to me like you need to practise extreme caution!

Do the following:
(everyone should do this anyway, at least informally in your head)

• Diagram or list which breakers control which outlets and lights.
• Determine the rating on each breaker, and try to confirm that the breaker is appropriate for the gauge of wire in the outlet box (or leading from the panel).
• Compile a list of everything connected to each breaker, including power ratings (if you really want to, you can probably ignore the little wall adapter stuff, like cell phone and battery chargers, but it is important to be thorough, so there isn't really any point skipping stuff).
• Add them up and see if you are out of spec on any breaker.

Having done all that, you probably have a good idea of problem areas, and where you might find outlets that can help transfer load to fix those problems.

The fact that you have gotten away with it so far is nice, but materials deteriorate over time, so it isn't a guarantee.

As for the two-prong / three-prong problem.. I will go collect links to previous threads discussing it later..
posted by Chuckles at 5:22 PM on September 16, 2006

While you are waiting for Chuckles to come back with the 2/3 prong threads, terrify yourself with this one about ACs that I remembered off the top of my head...
posted by nanojath at 7:33 PM on September 16, 2006

If you don't have grounded outlets, there's not much you can do other than installing GFI outlets in their place and if you are renting, your landlord probably won't do it for you.

So should you resort to kerosene lamps and fireplaces? No more than you would stop driving if the only thing available was a car with no seat belts. We lived for sixty years without grounded outlets and people weren't dropping like flies. There is a slightly higher risk, but that wouldn't stop me from using modern electric appliances.

Your original question was whether you should be worried about your equipment starting a fire. The answer is that your breakers, if installed properly, will prevent a fire.
posted by JackFlash at 8:36 PM on September 16, 2006

Actually, the thread nanojath links is pretty thorough :)
So, I think I will collect the 2-prong 3-prong thing some other time.

I totally agree with JackFlash when it comes to the magnitude of the threat, but it just isn't the kind of answer I want to be giving. In particular:

This comes back to my personal ideas about what good AskMe advice answers look like, and it will help to change the way I write them. I only want to assist people to find their own way, and I am happy to be responsible for the implications of that

Hopefully I will learn to make it less terrifying, and more empowering - just, you know, sensible empowerment.

One more thing from a previous question - Will I burn down my apartment?

You should not be relying on the breaker to tell you when you have overloaded the circuit. The breaker is your safety mechanism, it is supposed to be a back up, it is not your first line of defense. You should know how much load you are putting on a circuit, and you should make sure that you don't overload it.

My statement did imply that you could use the breaker as a gauge for when you have over done it. That is not correct!

posted by Chuckles at 9:56 PM on September 16, 2006

Chuckles is correct, and as a matter of course you should restrict loads to 80% of the wattage figures Jack Flash gave you, especially for the A/C and Space heater.
posted by scottymac at 10:56 AM on September 17, 2006

- Yes, you could start a fire. Breakers and GFCI's prevent sharp/uneven draws -- i.e., electrocution -- not slow burns. Fires start when wires (e.g., extension cords and whatever's in the wall) melt. Spreading stuff around is a good idea.

- Three-prong-to-two-prong adapters are always a bad idea, for a couple reasons. (1) No 3-prong outlets in the house may mean nothing is grounded, which means you can get shocked if there's a short in any of your electrical stuff. (2) Your surge protectors don't work at all without a 3-prong outlet, for various reasons. None of your electronics are protected.

Advice (i.e., what I would do): Since you're in LA, and in a 100-year-old house, I'm guessing you live near Baller Hardware in Silverlake or Tritch in Eagle Rock. Go there and buy a $1.99 tester and ask them how to shove it in the outlets to test for groundiness. You may be lucky and the electrical box and cables in the wall may act as a ground, which means you can just replace the 2-prong outlet-guts (after shutting off the breakers) with a 3-pronger.

Much, much better advice (i.e, what my wife would insist that I do): Call your landlord, and tell him/her your concerns. Without grounded outlets, you're not safe in the house, which in LA is a totally legit reason for you to insist that they repair the place. Even in the worst-case scenario (shitty old wiring in the walls, no ground), an hour of a licensed electrician's time is only about 75 bucks, and he/she will give you much better advice about how to run your electrical life better than we can. And in the best case, the electrician can wire up your outlets with 3-prongers and you can go on your merry way!

(Seriously, even if you have to pay for it yourself, call an electrician -- then deduct the cost from your rent.)
posted by turducken at 3:11 PM on September 17, 2006

Breakers certainly do protect against fire.. You just shouldn't use your safety system to measure the load. One way to think about it.. You want to be protected from a single failure, but if you are using your safety mechanism as a basic functional element (measuring load), then a single failure could burn down your house. If, on the other hand, you independantly determine that the load is safe, and you have a breaker, then your estimation and the breaker both have to fail..

No 3-prong outlets in the house may mean nothing is grounded, which means you can get shocked if there's a short in any of your electrical stuff.

You can only be electrocuted if you complete a circuit (the current has to come into you at one voltage, and go out at another). In a house with grounded outlets, this can happen with only one failure, because you are never too far from ground (computer case, metal body of permanent light fixture, anything with a three prong plug). In a house without grounded outlets one failure is enough in the kitchen and bathroom (your water and sometimes drain pipes are basically ground), but the other rooms are complicated. The grounded shield on the television cable or antena wire might be enough to complete the circuit, a damp enough floor might, and metal framing around a window might too. Or, a failure in a second electrical device..

Finally, having lived in a large city all my life, I find that surge supressors are uneccissary. I have a few now, but only because they were as cheap as any reasonable alternative. I don't recommend spending extra money on surge suppressors unless you are solving a problem you know to exist. Of course it's a moot point, because surge suppressors are so incredibly inexpensive, but..
posted by Chuckles at 9:15 PM on September 18, 2006