uber-simple HV wiring: Electrician really needed?

[IVB]

I need to install a light in 3 different closets where none exists. to keep cost down, i'm fishing the wires myself and running to junction box. (Or in the 2 closets where its barely visible, copping out and using surface-mount conduit).
 
I know High Voltage is a LOT more dangerous than low voltage, but do I really need to hire an electrician just to open up a junction box, add 1 more wire to the black, 1 more wire to the white? No access to the fuze box is required. I have a crazy # of low or barely utilized circuits (just did a full mapping of every light or outlet in the entire house). By barely utilized, I mean 2-5 60W lightbulbs on 2 different circuits.
 
These aren't long runs, the junction box is always within 10 feet. I'll make sure I staple the wire to the boards every few feet (except obviously inside the conduit).
 
If the answer is "yes" then okay, i'll respect that, but I want to make sure I'm not doing something silly.

 

[az1324]

If you know or learn and follow the code requirements and you are comfortable doing it then of course you should.  The only possible reasons not to are if you are worried about selling the property or insurance claims.  But even in those cases I believe you can pull a permit and get an inspection.

 

[wuench]

Absolutely no need for an electrician.  You can easily do it yourself as long as you are comfortable doing so.  And it sounds like you are already off to a good start.
 
1.) Do your load calcs for the circuit (sounds like you did, but hopefully you did it correctly, if you have outlets on the circuit you have to add estimates for those, never know what someone might plug in like a space heater).
2.) Do your box calcs, you are only allowed a certain number of wires in a box, if you have to, replace the box to get the right cu. in.
3.) Since you are using conduit make sure you are within the limits of it if it is existing, or use the correct size if new.
4.) Turn the power off, and I still always check with a circuit tester.  Things like shared neutrals can cause power to still be flowing thorough a box even if the circuit is off.  I always wear gloves and use insulated tools too as much as possible.  Had a couple of close calls/surprises.
5.) Use insulated staples, you are supposed to staple every 16in or so but that is not always possible especially in retrofit situations.  And leave a "service loop" enough wire outside the box so you have some extra to work with now and in the future.  Usually I just push it back out of the box a few inches.
6.) I like to use the wago lever nuts instead of twist nuts because in this hobby you usually end up going into a box several times and twisting wires weakens them.
7.) I also like to use adjustable deep boxes.  Make sure they are level or it will look bad when you are done (studs are not always plumb).
 
There's the planning and there is the skill part of it.  That's just something you have to pick up, like how much wire to leave in the box, how to push them back in so they are not under tension, etc.
 
EDIT: And CML's not that hard either  ^_^

 

[sda]

Even a cro-magnon can do it.  
 
Don't forget to add 1 more wire to the bare/green (ground).
You might need to get bigger wire nuts depending on the number of wires being connected.
 
Make sure you use the right size cable, 12g on a 20a circuit, 14g on a 15a circuit.
 
Don't overfill your boxes.
 
If you're using metal conduit ( a ) put a fitting where the NM enters and ( b ) pigtail a ground in the switchbox.
 
 
 
 

 

[IVB]

I'm using new PVC conduit, since there's only going to be 2 max 12/2 or 14/2 I stuck with 1/2" (which is within the limits, Home Depot had a cheat sheet).
 
The one thing I do need to look up is whether conduit needs to be fastened to wall every x inches or feet.
 
Thx for the replies. I'll have to talk it over with the wife and see what she prefers. I suppose 1 day of an electrician isn't too awful, I might be able to find enough stuff for 8 hours of work but gawd I hate spending even that much. (No electrician will come out for less than 6-8 hours)

 

[Madcodger]

So... a slightly different view...

We are selling our home repair & remodeling business at the end of next week, and after a few years of owning it (and admittedly being more of an investor than a worker, but still with a lot of renovation miles on me over the years), here's my advice:

If you are at all uncomfortable doing anything with electricity or plumbing (or framing, for that matter), hire a professional.

Whether you are a genius or limited in intellect, you can do something stupid. I've seen PhD's do some amazingly stupid things in home repair and have had excellent surgeons that never did quite understand a relatively simple lighting circuit. So don't feel bad if you don't know how to wire a house. It's a skill and it takes time (and aptitude) to learn it.

If your level of understanding is "black to black / white to white", I'd hire an electrician. We've run across many a circuit where that white wire has been repurposed, for example. So CAN a homeowner do an excellent job at rewiring? Absolutely! We see it all the time. But they've normally had someone teach them (by far the most common way to learn) or they spent quite a bit of time learning on their own, with mistakes along the way.

And finally, you CAN find an electrician who will come out for a couple of hours. We sent them out all the time for that! Find a reputable person you can work with, respect the fact that they need to make a living just like you (so pay for quality and skill!), and form a relationship where you have a company you can call when needed.

Just my two cents, since you asked.

 

[IVB]

Sigh. Like all of my HA projects, nothing is as easy as it seems in this 102 year old house. Turns out there's tons of knob & tube in the crawlspace (which I knew). What I didn't know was that its in pretty awkward condition.
 
I may need a sparky after all. Looks like a bunch of this should get ripped out before the next big earthquake.

 

[pete_c]

I didn't know what you meant by knob and tube so I looked it up.  Yup; here wife had it in her grandparents home.  We did pay to have the electrical updated throughout the home.  I have a DIY friend who did whole sections of his home while living there with his family.  They would just move to a different section of the house; party DIY and subcontracting stuff.  It was an over the years type update.  Here in current home have added electrical conduit and new circuits to the fuse panel (newer though) doing one at a time. 
 
Attached is a picture of knob and tube wiring.

 

[sda]

I'm using new PVC conduit, since there's only going to be 2 max 12/2 or 14/2 I stuck with 1/2" (which is within the limits, Home Depot had a cheat sheet).
 
The one thing I do need to look up is whether conduit needs to be fastened to wall every x inches or feet.
 
Thx for the replies. I'll have to talk it over with the wife and see what she prefers. I suppose 1 day of an electrician isn't too awful, I might be able to find enough stuff for 8 hours of work but gawd I hate spending even that much. (No electrician will come out for less than 6-8 hours)

You might be able to get two 14/2's into 1/2" pipe, but you're over filling it.  Even pipe has fill rules.  You should still put a fitting on the end, I use a coupler.  And staple the cable a few inches before entering the pipe.
 
IMO and experience, PVC only belongs in the ground.  It looks awful when exposed, its never straight.
 
You'll notice that when the conduit enters the box, there will be a gap between the wall and the pipe. Its hard to make a proper offset in PVC, but they do have these.  It probably won't bother you today, but next year it will.

 
For all the hassle you're going through, fishing the wires in the wall would be easier and look better.
 
K&T?  Ugh.  That puts a whole new spin on this.  You're not supposed to tie into an existing K&T circuit. 
 
There's was nothing wrong with K&T when it was originally installed.  80 to 100+ years later the insulation is decaying and who knows what previous owners have done to it.
http://en.wikipedia.org/wiki/Knob_and_tube_wiring
 
Here's something you don't want to hear.  These days, if you modify just about any circuit (K&T or otherwise) you're supposed to retrofit it with an AFCI breaker (or GFCI for wet areas).  If you have an old panel there probably isn't an AFCI breaker for it.  This triggers a panel replacement (or a subpanel install), or even a service upgrade.  A simple project can quickly turn into a many $K upgrade. 

 

[IVB]

You might be able to get two 14/2's into 1/2" pipe, but you're over filling it.  Even pipe has fill rules.  You should still put a fitting on the end, I use a coupler.  And staple the cable a few inches before entering the pipe.
 
Here's something you don't want to hear.  These days, if you modify just about any circuit (K&T or otherwise) you're supposed to retrofit it with an AFCI breaker (or GFCI for wet areas).  If you have an old panel there probably isn't an AFCI breaker for it.  This triggers a panel replacement (or a subpanel install), or even a service upgrade.  A simple project can quickly turn into a many $K upgrade. 

 
Thanks for the note. Am I reading the fill chart wrong, I thought I was well under capacity? Here's one online chart: http://sparkyjohn.com/pipefill/pipefill.pdf
 
The panel itself has been upgraded, but it looks like for perhaps 3-4 lights they just took a circuit, ran a new style wire off it, and connected to the knob & tube. I think its just the one wall that needs to come down, potentially two. Ugh.

 

[pete_c]

Guessing here I just like metal conduit over pvc conduit. 
 
Typically I will bend the pipe if needed and put together the pieces loosely to see the fit and never really have put in more than 6 14 guage wires in a 1/2 inch EMT.  Outside over doing it some used PVC and burial type of jacketed electrical cable.  That was me though. Over did it a bit with GFCI's just about anywhere in the basement and adding GFCI's to the outside boxes.   Last week I was just doing some electrical and having a bit of a hard time putting a GFCI outlet in an all metal 4" metal box as it had conduit running through it on both sides.  I loosed the conduit connectors a bit moving the box a touch such that it wasn't near the conduit when I installed.  I do tend to use all metal boxes and covers for basement stuff; looks a bit utilitarian (pun there) though.
 
I have added pvc jacketed wire in Florida to existing wiring.  Always paranoid about doing something to the wall and damaging the wiring; that is me.
 
I have a small collection of those glass / porcelain insulators that they used many years ago; so rare to see them these days ...thinking of them as collectors items.  (that and glass door knobs).
 
Think though if you take walls down to upgrade your electrical stuff; upgrade or pull LV wires for your automation stuff; as its much easier to do with no walls up.
 
Yup I have a peer I worked with who was working there on the left coast in 1989 during the Loma Prieta earthquake.  He left minutes afterwards in his rental car driving back to Chicago direct non stop; never to return again. (worked for an airline).  Thinking it did cause some deep seated psycological issues as he wouldn't even work on any left coast projects afterwards.

 

[wuench]

There is nothing about hiring a professional that means it will be done right.  So it is still good to educate yourself so you can supervise the job.  That being said,
If it were me, I would either look into running it new all the way back, or get a local inspector and/or an electrician or two to look at it.  I might still do the job myself, but I would want some advice from a pro.
 
I have not worked with knob and tube, you can tie into it, but the biggest concern in my mind would be that you are adding extra load to the knob and tube wiring and you may risk overloading it, especially if it is at all damaged/brittle.  I definitely wouldn't put any outlets on it, since you never know what might be plugged in and I wouldn't add anything unless the entire run could be inspected.  You really don't want to add load to it and have a weak spot in a wall or something that would heat up.

 

[IVB]

And the hits keep on coming. I went up into the attic to confirm that the junction boxes were of the new wiring, not the knob&tube (only 20% of the house is k&t).
 
The damn roof support bars are bowing something wicked.  Fixing it now is several thousand, fixing it after the roof caves in is, uh, more.
 
My token comfort is that I found this myself now when its hopefully cheaper than later. Plus there is some stuff I can do myself, stemming the blood flow.

 

[JimS]

Ummm...  I can't resist saying "If you have to ask, then maybe you shouldn't do it yourself."    But you have gotten good advice from others.  And I second that if you pay someone else that doesn't always mean it will be done right. 
 
I've dealt with some messed up electrical work, including a splice in a wall behind a meter base (no box) that then went to three fuse panels, but never had to deal with knob and tube.  I would be ripping that out at the first opportunity and not messing with it before removal.  Splicing into it sounds like just asking for trouble.  But I am not an electrician - just my opinions. 

 

[sda]

Thanks for the note. Am I reading the fill chart wrong, I thought I was well under capacity? Here's one online chart: http://sparkyjohn.com/pipefill/pipefill.pdf
 
The panel itself has been upgraded, but it looks like for perhaps 3-4 lights they just took a circuit, ran a new style wire off it, and connected to the knob & tube. I think its just the one wall that needs to come down, potentially two. Ugh.

Those charts are for THHN, a single wire, solid or stranded.
NM (aka Romex) is obviously bigger.
All you can get is one 14/2, maybe a 12/2, in a 1/2" pipe.     
 
You can extend K&T with more K&T (NEC article 394), but you can't extend it with NM or any other wiring method.
And K&T is supposed to be run in the open, no insulation around it.