[geeks] D'OH!

[geeks at sunhelp.org]

~ -----Original Message-----
~ From: Mike Hebel [mailto:nimitz at owc.net]
~ Sent: Saturday, February 02, 2002 4:22 PM
~ To: Jim Carver
~ Subject: Re[2]: [geeks] D'OH!
~ 
~ 
~ JC> Mike Hebel wrote:
~ 
~ >> I put in two 30A circuits myself for my systems.  Wired 
~ with 12/3 in
~ >> conduit no less.
~ >> (I figured a '50's cape cod style house I wasn't going to 
~ take chances
~ >> on the existing wiring being heavy enough.)
~ >> 
~ >> 'Course I also have a 25A that runs a sump pump, fridge, 
~ iron, small
~ >> fountain, and paraffin hand tub at once as well.
~ >> A little overkill for those...but hey, better safe than sorry!
~ >> 
~ 
~ JC> You're out on limb Mike. 12 ga. copper is only rated for 
~ 20A. For 30A
~ JC> you should be using 10ga cu. You probably won't be exceeding the
~ JC> built in safety overload factors, but you are exceeding the NEC or
~ JC> National Electrical Code. That "little book" that 
~ inspectors and your
~ JC> insurance company look at as the "bible".
~ 
~ _That_ I didn't know but probably should have.  (My mind is re-growing
~ brain cells after my two months of retail OKAY! ;-)
~ 
~ Still,  I'm thinking about re-wiring again so maybe I should go with
~ 10ga wire.  The problem is that I think I'd have a hard time fitting
~ that into the existing conduit.  Thankfully this is no where near a
~ "finished" basement.  Probably won't be happening soon though - and I
~ happen to have half my systems in the process of being re-configured
~ so the load at the moment is quite light.
~ 
~ Mike                         mailto:nimitz at owc.net

While your at it, you should know that everything on the branch needs to be
rated for the breaker value. In other words, you CAN run 10ga on a 30A
breaker for an outlet branch, but you CAN'T find 30A "normal plug" outlets.
In fact, you aren't supposed to use inexpensive 15A outlets on a 20A branch
either. 20A 110V non-locking combo-outlets look like normal outlets, but the
right hand pronghole looks like the letter T on its side so it can accept
both 15A and 20A plugs. I will admit that its a common cheat to use a 15A
outlet on a 20A branch though, and I'm guilty. Also, both 15A and 20A
outlets won't properly accept 10ga wire. Use two 20A branches for your
application. The systems will like it better too, as you will surely get
voltage sag if you approach 25A on your current branch wiring, and the
inrush current of a switchmode powersupply starting (ie: most computer
supplies after 1985) will be better accomodated.