First and foremost, sorry to hear about your loss and situation. I will be praying for you.
(sorry for the long post)
As a long time computer tech I hear about these types of things all the time. Having a father with almost 30 years at a power plant plus fire department allows me to see and hear the stories of what is possible.
There can be several causes:
First the age of the house, if it was built from 1990 or older, then it likely has 12 or 14 gauge wire
(or smaller in rare cases if the builder went cheap)In all my years I have NEVER seen a house wired in smaller than 14AWG. The first wiring done in the early 1900's was 12guage knob and tube, even later jute covered wiring was at least 14 AWG for current carrying conductors, though a few years they did use cable with a reduced size ground(when ground wire was first used)
instead of the suggested 10 gauge, which over the span of the entire house means it can be spread thin.
14AWG and 12AWG is what is commonly used, it is the NFPA 70(National Fire Protection Agency) or also known as the NEC(National Electrical Code), required wiring for most receptacle circuits, when installed properly and not overloaded, is sufficient.
They problem most people run into is builders skating by with code required minimums. In today's world of electronic/powered everything, it is often not quite enough. Proper installation of dedicated circuits, and installing more than the code required minimum circuits, you will not ever have an issue if you don't overload the receptacle or circuit.
The other big issue that I have witnessed is the stab-in receptacles. I have personally witnessed these being the cause of a fire. I have worked many burn jobs, when the cause was electrical these were often the start-combined with overloading.
Example:
14AWG wire------------[A]------------[B]---------------[C]-----------[D]
The receptacles a,b,c, and d are stab-in, and fed thru the receptacles, non pigtailed(unfortunately VERY common and is done this way alot of residential wiring)
The lady of the house had a floor lamp plugged into receptacle A, and she plugged in a space heater into receptacle D. A baby crib was in front of receptacle C, after some time she smelled something funny, and suddenly the smoke detector went off.
Receptacle C had started melting and caught the paper face of the wall board on fire. Fire was called out, investigation showed the wiring was stabbed into the receptacle and was being fed through the thin, little metal tabs inside the receptacle. The thermal cycles opened the gap between thin metal tabs and wires, causing arcing and heating, leading to the literal meltdown. There is no way to predict when and where such a failure may occur, why not in receptacle A or B? The
Thankfully no one was injured and the newborn was in a bassinet in the living room at the time.
Proper pigtailing and use of screw terminals with more contact area may have prevented the fire. Personally I prefer using "spec grade" receptacles with a screw clamp type of contact. The added benifit of these, the actual receptacle to plug connection is of better quality also.
Get a high powered draw on it like microwave, several computers, cheap surge protector, stereo equipment, big (tube style) TVs and so on, it can cause all sorts of problems.
Again overloading is the real issue here.
My house was built around 1980 so this is why I have mostly switched to lower draw LCD screens (TVs and computer monitors), more efficient power supplies in the computers and $40-60 surge protectors and battery backup. With 3 computers, 3 monitors, decent 5.1 speaker system, printer and the usual small items, I have measured the total power draw is just under 400W which is well within the old wiring capability. I have seen spikes just over 500W when I do some gaming where the video card, power supply and speakers are working harder but that is
still within the maximum 800W max draw for the house wiring (14ga wires) in this room to the junction box.
Incorrect. Not trying to start an argument, but also don't want this to mislead people. 14AWG (American Wire Guage) wire is rated for max of 15 amperes. The max recommended usage is 80%.
15 x 80% = 12 amps
P=IE Ohm's Law Power=AmpsxVolts
12 x 120 (volts) = 1440 watts per receptacle cicuit
It should be noted this is the MAXIMUM continuous usage for the circuit.
12AWG is 20 amps
20 x 80% =16 amps
16 x 120 = 1920 watts
Second, many times they are actually just a power strip, not a full surge protector. In those cases putting too much power can result anything from tripping the internal breaker on half decent units to causing the fire as seen from the original poster. Cheap units that also label themselves as a "surge protector" may be nothing more than just have an internal breaker that is supposed to trip if too much power (over 15A) tries to get in or is being drawn through it. If that breaker fails to do its job then we see the situation as seen in the original post. Stick with quality names, and ALWAYS look for a "Joule rating". The higher the joules the better the protection, but at minimum try to stay over 2000 Jouels per computer. 3 computers = 6000 joules.
Some quality names: APC, Belkin, Tripp-lite, CyberPower, Fellowes
Agreed. Too often folks cheap out on this.
It may help to spend $70-80 on a small battery backup unit, not for the battery protection but they also tend to have voltage monitoring, so if the computer tries to draw too much it will limit the power itself to prevent it from overloading. Also if the voltage drops or spikes, it will cut external power and use battery power until it returns to normal, many times just a few seconds. I usually hear mine beeping at minimum once a day from spikes or drops. Here is the UPC unit I have on my main system and modem/router:
APC BE650G (650VA, 390W). This is only suggested for one computer due to the 390W limit. If you have a high powered gaming computer or want multiple computers on one APC unit, then it would help to get at least a 600W or better unit.
Third, if you are making some home improvements or building an addition for a home office, speak with the electrician and ask him to only use 10 gauge wire in this room and all the way to the junction box on its own 30A breaker. Also having one or more GFCI outlets on the first outlet in the series for that room can help reduce the chance for problems as well. This means you would have 30A protection at the breaker, 15 or 20A at the GFCI (usually 15A for that outlet or 20A for other draw down the line from it), and usually 15A from the surge protector.
You would still have to pigtail to 12AWG or 14AWG at the receptacles, most receptacles available cannot accept 10AWG wire. You could wire most in 10AWG and pigtail in 12AWG with the circuit on a 20Amp breaker and it would still be legal.
In the case of the original poster, I might suggest 10 ga. wire to each room from the breakers, then 12 ga for the outlets, lights, and so on, except the computer room, insist on sticking with 10ga all around that room top to bottom. Some electricians may say that 12 or 14 ga is sufficient, but with my father working for almost 30 years at a power plant AND volunteer fire department, he has seen what electrician recommendations can do (same result as original poster). With more and more electric reliant devices out there, loading up a single outlet with cell phone charger, printer, wireless home phone, electric razor, may seem no big deal but 1A here and 4A there can start adding up quickly and pass the 15A rating.
It is up to the individual to spend the added cost of such a method, the other issue you run into is box fill. You can easily overload a box by using 10AWG in standard residential boxes. An inspector will shoot you down quick. An overfilled box can cause some of the same issues your good intention is trying to prevent.
Wow typed up a lot more than I expected.... as long as it helps a few people I am happy. I am looking for some exact distance and numbers for the various gauge wires but can't find my little black book... may edit and report back later.