Question about American Department wiring standard/requirement

[RMSMajestic]

It's wintertime and also time to restart Bitmining.

But when I was running my mining hardware (draws about 700W) yesterday, there was suddenly a power cut and resetting those circuit breakers doesn't work.

Today the management repair guy just came, looked at the wiring, and there's a big chunk of wire that completely burnt out.

The apartmant management office warned me about the safety and usage, However I noticed that they are only using 12AWG wires.

A bit of googling suggested that a 12 AWG wire can handle "41amps for chassis wiring and 9.3A for power transmission" which totals about 1023 Watts.
That number is a bit shocking cos a hairdryer/vaccum cleaner/ workstation computer can very easily exceed that number.

Am I legally eiligible for requiring the apartment to replace the wiring for my safety? Or is a mere 12 AWG still meeting the standards?


Many thanks in advance

[Cigarguy]

Don't know where your getting your info from but 14-2 Lumex is sufficient for 120V house wiring. They are rated for 15A/1500W and are North American building code certified. 12-2, properly installed, is rated for use in 20A circuits. How everything is installed and put together matters too. I suspect you are overloading the circuit. Get a hold of a copy of your local and state electrical building code and follow that guide. Better yet spend the money on a journeyman electrician.

[RealBlackStuff]

I think you should check the "burnt" wiring, that may have been 14AWG or even 16AWG.
What they should use in any case, is at least AWG12 (a.k.a. 12-gauge) with 3 copper cores (2 standard cores plus an extra ground core).
In USA this is the standard wiring for wall receptacles, light fixtures and small appliances.
At 120V AWG12 can handle max. 2400W (full load). Recommended use is no more than 80% (1920W).
At 240V AWG12 can handle max. 4800W (full load). Recommended use is no more than 80% (3840W)

For a more detailed explanation, see this: http://www.homedepot.com/c/factors_to_c ... e_HT_BG_EL

Off-topic:
If I had known that (most) houses in USA also have 220V options, I wouldn't have sold all that electrical gear when I moved here from Ireland!

[Cigarguy]

Off-topic:
If I had known that (most) houses in USA also have 220V options, I wouldn't have sold all that electrical gear when I moved here from Ireland!

We wired a few circuits for an English friend as 220V for precisely that reason. Not difficult to do and consists of mainly bridging 2 breaker circuits together.

[RealBlackStuff]

I know, I have 220V in my workshop and in my office, done by the local electrician.
I happened to bring over a few wall sockets from Ireland (same as in UK) that came in handy for that.
We brought adjustable beds over that run on 220-240V. They each have a transformer that drives the adjusting 24V motors.
I had planned to get a 110V-24V transformer for the beds, but (my self) laying a 220V cable from my workshop to the bedroom (above it) was a lot easier and cheaper.
Probably not by the book, but I can rip that cable out again in less than 5 minutes.

[theterminator93]

Typical for residential applications is 14/2 for 15A breakers and 12/2 for 20A breakers. GFCI receptacles and 12/2 are required for any applications feeding bath/sink/utility pumps. Longer cable pulls reduce the overall load capacity as increased distance causes greater voltage drops when current rises, causing a greater current value for a given power transmission rate - hence the overhead in "rated" cable amperage ratings.

If it was 12/2 wiring that burnt out, then the circuit breaker should be looked at. It sound to me like the wire that burned up was probably the feed from the load center for the circuit which your mining rig was on, but wasn't dedicated so it was feeding multiple outlets/devices and for a moment, the overall load on that circuit exceeded its design supply limit. Under normal circumstances the breaker would have tripped long before premise wiring would have gotten hot enough to cause damage to itself or anything else, but I'm wondering if there might have been a problem with the breaker that caused it to trip later than it should have, causing a fire hazard...

In short - if the circuit breakers were connected and functioning properly, there is no reason the premise wiring should have burned out.

[RMSMajestic]

Typical for residential applications is 14/2 for 15A breakers and 12/2 for 20A breakers. GFCI receptacles and 12/2 are required for any applications feeding bath/sink/utility pumps. Longer cable pulls reduce the overall load capacity as increased distance causes greater voltage drops when current rises, causing a greater current value for a given power transmission rate - hence the overhead in "rated" cable amperage ratings.

If it was 12/2 wiring that burnt out, then the circuit breaker should be looked at. It sound to me like the wire that burned up was probably the feed from the load center for the circuit which your mining rig was on, but wasn't dedicated so it was feeding multiple outlets/devices and for a moment, the overall load on that circuit exceeded its design supply limit. Under normal circumstances the breaker would have tripped long before premise wiring would have gotten hot enough to cause damage to itself or anything else, but I'm wondering if there might have been a problem with the breaker that caused it to trip later than it should have, causing a fire hazard...

In short - if the circuit breakers were connected and functioning properly, there is no reason the premise wiring should have burned out.

The burnt out part is right at the part closest to the connection to circuit breaker. although there must be other places (2/3 outlets are completely out in my room. And the remaining one show bad damage from heat)

I have always try to keep the total load under 2000W which is the safe limit I assumed. Last year there was a similar power loss, just that the power mysteriously come back the next day. (At that time I was running 3 miners, 700W+ 500W+300W, my W701 runnign BOINC (~150W) and two lamps ~72W), pretty high but still below safety limit.

On a side note last year my power bill was $70 less (excluding the bitcoins I have earned) than 2014,despite that winter last year was much colder. And now I kind of wondering if they charge different transmission fee for different lines. (The air conditioner is in a different line than those outlets )

Could this be a result of aging of wiring?

[theterminator93]

Replied to your PM just now.

What are the breakers rated for, 20A or 15A? It still really strikes me that the wiring got hot enough to burn without tripping the breaker and appears to have permanently affected several receptacles.

[thinkpadcollection]

Apartment wirings are infamous for being scrimped. My bedroom and nearly whole living room's is on one breaker. I had to put on a ban on a/c parents were trying to use had power kept cutting out on occasion long ago. 10K BTU by the way, too big.

12AWG is rated for 20A, 14AWG is 15A but with headroom as you did know correctly. Outlets are commonly used 15A design, when you see a 20A outlet you'll know, it is a T slot where widest slot is. You'll have to trace all the outlets and lights if are hooked into that breaker to that particular breaker, in order to see if these circuits are overloaded by design. And one bad news usually landlord will not separate the wirings ever.

Secondarily, PSU is your enemy, has losses which means 700W internally could be translates into around 900W even bit more if you are talking about drawing 700W at the outlet is plenty enough for everything else within limits depending on design of wiriing hook ups to one breaker.

And, YES, you are eligible to tell apartment to rebuild and split wirings if required as I like to say were scrimped on fewest breakers back then. By the way, previous apartment we lived in did have aluminum wiring, but we moved out almost 22 years ago and large, long 3 floor building is still there. Oh the memories, there was a 3 phase main switch/breaker, one of three contacts fizzled out left us in darkness and prompted emergency bypass on that contact to get same apartment powered back on in middle of winter. Later on, that switch/breaker rack panel were swapped out and I had seen the results of blown out contact. This is 800A breaker/switch panel btw for the main transformer, didn't remember if it is before the transformer or after that.

Make sure you do have copper wiring, not aluminum, replace all connections, switches, screw nuts and outlets, these outlets have 2 screws per phase as needed to daisy chain to next wirings. (hot and neutral); but in kitchen is required to wired as 2 breakers per outlet, one outlet socket to a breaker each, that is why there is a bridge between two outlet sockets is made to be broken into two as needed, insurance will *not* cover that aluminum wirings. I forgot to mention that previous apartment has the fuse panel ,yes fuses is about 8 fuses in total. Also make sure the wiring insulation covering is not silver or black and looks like cloth covered using pitch too but wire insulation were rubber or early plastic.

When things fry (as in burning, arcing, corroding, going black) cannot reuse/insurance issues as well the stuff by reusing wirings, scruffing the contacts and clean terminal screws especially high ampere power circuits because I used to be tv/electronics techanican repair for several years.

Update, you can see many wirings old and new, in most places usually are white plastic covered these days. The silver painted over cloth covered romex I seen that before in one older post war house we lived in with stepfather's during rework of wiring during running in natural gas pipes along properties also also we had converted over to natural gas for both new hot heater and water boiler. Was ancient oil fired giant boiler and electric hot water heater.

https://www.nachi.org/forum/attachments ... re-002.jpg

Cheers, thinkpadcollection