[Noisebridge-discuss] Computer Equipment in an old home?

Wed Jul 10 20:55:17 UTC 2013

all I can say about Dennis' post is: +1

On Wed, Jul 10, 2013 at 12:37 AM, Dennis Gentry <dennis.gentry at gmail.com>wrote:

> Everyone is right that you might not even be pulling too much current
> as-is, and it's cheaper to measure it than to add outlets.  In commercial
> buildings at least, the fire department will tell you to not daisy chain
> power strips, but you could fix that by getting a (UL approved) power strip
> with a zillion (OK, 24) outlets<http://www.amazon.com/Multiple-Outlet-Strip-w-Surge/dp/B00BHJCOSO/>.
>
>
> I searched pretty extensively for evidence that old "knob and tube" wiring
> was more dangerous than modern romex or wire in conduit, and couldn't find
> anything except hearsay.
>
> Two dangerous things are to cover it with (thermal) insulation (making it
> prone to overheating) or to splice in new wire (incorrectly?).  I recall
> finding something in the 2011 Electric Code<http://www.amazon.com/Wiring-Simplified-Based-National-Electrical/dp/0971977976>that said not to splice new wiring into knob and tube.
>
> I've found it pretty easy to run new circuits from a panel, and as stated
> above, fuses are reliable, safe technology as long as you don't bypass
> them.  Code in SF (deltas from NEC 2007 here<http://archive.org/stream/gov.ca.sf.electrical/ca_sf_electrical_djvu.txt> --
> thanks, Archive.org!) doesn't require conduit, only Romex protected from
> physical damage, and the biggest part of the work is crawling around
> drilling holes and fishing the wire through.  I can't remember if it is a
> requirement, but I keep my new romex and fixtures at least a foot from old
> knob-and-tube once it leaves the panel area.
>
> If there isn't room in the existing panel for new circuits, it is a
> slightly bigger deal, but it's often cheapest to leave the existing panel
> in place and add either a new panel or a sub-panel if the existing panel
> has the capacity for a sub-panel (you may have to poach one of the existing
> circuits and then feed it from
>
> Once you have the wire installed, the outlet itself is pretty easy, they
> make "new work" electrical boxes that are easy to install in drywall and
> possible to install in lath-and-plaster.  (In drywall, with a drywall saw<http://www.amazon.com/Stanley-20-556-6-Inch-FatMax-Jab/dp/B00005QVQH>,
> cutting a hole is trivial.)  I usually install GFCI outlets, but if there's
> no water anywhere near, a regular grounded outlet is fine.
>
> For adding outlets, you're supposed to get a permit.  Last time I got a
> permit for homeowner electrical work, it was about $45 and the inspector
> was super helpful -- neither of us wanted to burn down the building.
>
> Good Luck!
> Dennis
>
>
> On Tue, Jul 9, 2013 at 9:24 PM, Martin Bogomolni <martinbogo at gmail.com>wrote:
>
>> I second the "replace the wiring" strategy.
>>
>> In one of the older victorians near Alamo Square, I helped a friend
>> rewire the house using molded conduit in various rooms.   We also
>> replaced the mains panel with a new one that had breakers (rather than
>> glass fuses).
>>
>> It's not a trivial project, but it can be a relatively straightforward
>> one.   Cost of materials and wiring for that project was ~$1200.
>>
>> -M
>>
>>
>>
>> On Tue, Jul 9, 2013 at 5:49 PM, Adrian Chadd <adrian.chadd at gmail.com>
>> wrote:
>> > ... turn-on current.
>> >
>> > TThe rush of turn-on current on a strip of electronics is not
>> negligible.
>> >
>> > I'd also be surprised if ye olde house wiring is actually safe at
>> > drawing 15A. You may find it's actually not safe to drive it at that
>> > for very long.
>> >
>> > Combine that with all the myriad ways that these things are hooked up
>> > behind the scenes - American houses seem have this habit of having
>> > separate wiring for lights-that-terminate-on-wall-sockets versus the
>> > occasional high-powered wall socket for something more than a light.
>> > So it can all be quite deceptive. Your light circuit may not really
>> > terminate a full 15A, let alone the higher rush when all your devices
>> > turn on.
>> >
>> > Add in all the possible damage and failure cases with that wire, with
>> > say weather and other environmental effects, and there's quite a lot
>> > of potential "wtf?" going on that a fuse just won't tell you about.
>> > And that's the kind of thing that can start fires and/or kill people
>> > in other creative ways.
>> >
>> > Circuit breakers can detect and cut off these transient current
>> > rushes. Fuses in mains wiring tend not to. I'd personally upgrade
>> > everything to circuit breakers. If you start having some intermittent
>> > circuit breaker resets, you can be sure you've done something stupid
>> > or there's some transient dodgy wiring somewhere.
>> >
>> >
>> >
>> > -adrian
>> > (I don't fuck around when it comes to mains electricity.)
>> >
>> > On 9 July 2013 17:40, Jake <jake at spaz.org> wrote:
>> >> Hi Brian,
>> >>
>> >> I agree with what Gopi says - use a kill-a-watt to measure how much
>> power
>> >> you're using if you're afraid of overloading the wiring.
>> >>
>> >> but instead of that, you can simply get a power strip and plug
>> everything
>> >> into that.  A power strip has its own circuit breaker (15 amps) and
>> that
>> >> will trip before you blow a fuse.
>> >>
>> >> If your whole room is running from an extension cord from somewhere
>> else,
>> >> use a power strip (with its own circuit breaker - they all have one)
>> where
>> >> that extension cord plugs in.  You can also use a GFCI adaptor like
>> this:
>> >>
>> >>
>> http://www.amazon.com/GFCI-Outlet-Adapters-Single-Adapter/dp/B001OE3JHC
>> >>
>> >> That will get you a lot of protection.  If you take too much power in
>> your
>> >> room, you might pop the breaker in a power strip, or you might blow a
>> fuse,
>> >> but it shouldn't cause a problem otherwise.
>> >>
>> >> The thing is, most modern electronics don't use very much power.  You
>> can
>> >> have ten desktop computers and LCD monitors on one 15 amp circuit (1500
>> >> watts total).  A cellphone charger is up to 5 watts - you can have 300
>> of
>> >> those!
>> >>
>> >> All this goes out the window if you try a toaster, electric oven, or
>> space
>> >> heater.  Forget it.  Also those big hot halogen lamps use a lot of
>> power.
>> >> But you can read the labels and do the math.
>> >>
>> >> If you want to preserve the wiring you have and keep it from messing
>> up,
>> >> just don't mess with it or allow things to flex.  The solid wires in
>> the
>> >> walls are not meant to move, they are stiff.  So if an outlet is loose
>> and
>> >> flops around, either tune it up or plug a power strip into it and
>> screw the
>> >> cord of the power strip to the wall, so it doesn't move things around.
>> >>
>> >> The fuses in your fuse box are fine.  This technology is very reliable,
>> >> moreso than many circuit breakers!  A fuse is very unlikely to fail to
>> fail,
>> >> if you know what i mean, which means it will protect you.  Of course
>> if a
>> >> fuse has a penny stuck under it (someone tried to save the cost of a
>> new
>> >> fuse) then there is no protection.  The screw-in fuses were designed to
>> >> allow you to put a lightbulb in place of a fuse to diagnose shorts.
>> When the
>> >> bulb stopped lighting up, there was no more current draw and you could
>> >> install a new fuse.
>> >>
>> >> long story short, it's not the number of things you have, it's the
>> total
>> >> power draw, which will be limited by the fuse and any power strips on
>> the
>> >> way.  And don't let that old wiring move around or it might break.
>> >>
>> >> -jake
>> >>
>> >>
>> >>
>> >> Brian Perez wrote:
>> >> Hey all, since SF has a lot of old buildings I'm sure someone could
>> help me
>> >> with this problem I'm facing.  I have an old home (circa 1930s) and
>> all the
>> >> wiring is the old copper cloth-covered kind and there's BARELY an
>> outlet in
>> >> the house.  My room has no outlet; my power is pulled through the
>> window to
>> >> the back room and up to the light socket.  BAD, I know.
>> >>
>> >> Being the tech guy I am I'm starting to run out of sockets with the
>> >> extensions I have.  There's basically three surge protectors daisy
>> changed
>> >> to power everything in my room.
>> >>
>> >> What are my options to make this more secure and safe? (And
>> potentially add
>> >> more sockets)
>> >>
>> >> Thanks!
>> >> Brian
>> >>
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