.

[Zulu Kono]

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[Whitegas Extraordinaire]

If a guy were adding a circuit, is there any good reason why he shouldn't
mix 12 and 14 gauge wire along it, provided he's using a 15-amp breaker?

[Northman49]

What do you mean by "mix"? You have a junction box somewhere along the way?

[Zulu Kono]

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[Ridge_Runner]

If a guy were adding a circuit, is there any good reason why he shouldn't
mix 12 and 14 gauge wire along it, provided it's on a 15-amp breaker?

No, not really. Unless it’s copper and aluminum conductors—they don’t play well with each other.

If it’s solid copper conductors just make sure your splices are nicely twisted and made up tight. Sometimes the two don’t “marry-up” quite like stranded conductors.

Just out of curiosity, is this a project where you’re trying to use up some scrap lengths of wire? Or over sizing the wire to compensate for the voltage drop of a long distance run?

[bowenstudios]

Simple answer is it should be fine. That being said I would make sure the 14 is what is attached to the breaker. You dont want someone coming in later and thinking they can upgrade to a 20 amp circuit only to create a fusible link along the way. Also check code, some areas are very strict. My house has a fun mix of wire gauges, but all I've dealt with so far are heavier along the circuit, lighter at the breaker.

[Zulu Kono]

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[mksmth]

We fuse the circuit for the smallest wire attached. We also mix conductor sizes all the time. Especially in long runs like parking lot lighting. Mostly for voltage drop. Motor loads like ACs you can have an over sized fuse for the conductor.

[bowenstudios]

Thanks for the replies, gentlemen.
All solid copper 12-2 and 14-2 romex.
The idea is to re-use lengths of wire from circuits I removed
previously, plus add in a couple of lights using 14 gauge,
which is obviously cheaper and waaay easier to work with
I guess "adding" a circuit isn't really what's going on here.
I'm more like re-configuring and extending one.
It already comes out of the panel and to the first J-box as 12 gauge, so I'm leaving that.
I'll write on the wire in Sharpie that the circuit has 14 gauge wire on it.
Not worried about code, no inspector will ever see this while I'm alive.
I trust my own work more than some licensed electricians I've known.

Your last sentence is so very true. My dad was an electrician for the county, lots of stories where things like like union electricians buildings a new school were behind so they just put receptacles in without attaching the wires, about half of a new school. I helped a community center with a kiln once that I swear was trying to burn the place down to get insurance money. Their "licensed" electrician wired a 60 amp circuit for an electric kiln, I had to turn the receptacle over to relieve the tension on the wire and found that he didnt tighten the lugs down, the wires just fell out.

I'm glad I've had good craftsmen in my life to teach me how to do most things and to always double check others work.

[bowenstudios]

We fuse the circuit for the smallest wire attached. We also mix conductor sizes all the time. Especially in long runs like parking lot lighting. Mostly for voltage drop. Motor loads like ACs you can have an over sized fuse for the conductor.

So would you mark the panel box or wire at the breaker like zulu kona said to make sure that it was known there was a lighter gauge wire in the circuit? Also as I understand that 14 will handle 20 amps just fine, but is not technically recommended.

[Ridge_Runner]

>>Your last sentence is so very true. My dad was an electrician for the county, lots of stories where things like like union electricians buildings a new school were behind so they just put receptacles in without attaching the wires, about half of a new school.

Mike, funny you mention that. We’ve been chasing this exact issue in a couple buildings on campus for several years. Large apartment style dorm buildings that were built by the same GC and subs. Once in a while we still get a call for a room with an outlet(s) that have no power, only to remove the receptacle and find the wires tucked in the back of the box...

[Zulu Kono]

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[Rfieldbuilds]

Thanks for the replies, gentlemen.
All solid copper 12-2 and 14-2 romex.
The idea is to re-use lengths of wire from circuits I removed
previously, plus add in a couple of lights using 14 gauge,
which is obviously cheaper and waaay easier to work with
I guess "adding" a circuit isn't really what's going on here.
I'm more like re-configuring and extending one.
It already comes out of the panel and to the first J-box as 12 gauge, so I'm leaving that.
I'll write on the wire in Sharpie that the circuit has 14 gauge wire on it.
Not worried about code, no inspector will ever see this while I'm alive.
I trust my own work more than some licensed electricians I've known.

Your last sentence is so very true. My dad was an electrician for the county, lots of stories where things like like union electricians buildings a new school were behind so they just put receptacles in without attaching the wires, about half of a new school. I helped a community center with a kiln once that I swear was trying to burn the place down to get insurance money. Their "licensed" electrician wired a 60 amp circuit for an electric kiln, I had to turn the receptacle over to relieve the tension on the wire and found that he didnt tighten the lugs down, the wires just fell out.

I'm glad I've had good craftsmen in my life to teach me how to do most things and to always double check others work.

Easy to make assumptions like this, but often and especially with high draw circuits that heat up alot, the expansion contraction will cause wires to loosen up. Whenever I install panels that I know will have high demands, I’ll ask my customers to have me back in 6-12 months to retighten everything.

[Zulu Kono]

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[Rfieldbuilds]

Easy to make assumptions like this, but often and especially with high draw circuits that heat up alot, the expansion contraction will cause wires to loosen up. Whenever I install panels that I know will have high demands, I’ll ask my customers to have me back in 6-12 months to retighten everything.

The only circuits I have that I'd think are high-draw would the the obvious ones,
I.e., range, dryer, and water heater, all of which I wired into the panel myself.
I know I torqued them in tight, but maybe I need to revisit?

Here's another question, maybe sort of a "myth-buster".
Someone (not an electrician) once told me that the more
wire you have in your house, the higher your power bill will be
because all of that wire is always energized, even though particular
fixtures might not ever be used, e.g., electric wall heaters.
I don't buy it, but I am curious as to whether or not it's actually true, because
in some cases I like to leave extra wire in a given run in case it's ever needed.
I get that a guy could just shut down the breakers, but that's beside the point.

Old wives tale. You wont notice a difference one way or another.

As far as the loose connectors, we regularly receive custome built panels for special applications and I go through everyone and retighten lugs after receiving the panels. From a metallurgical standpoint, the wires kind of “relax” according to an engineer friend. I cant speak to that but do know the expansion contraction issue I mentioned above is real. Retighten your (de-energized) lugs and you will be a believer.

[mksmth]

We fuse the circuit for the smallest wire attached. We also mix conductor sizes all the time. Especially in long runs like parking lot lighting. Mostly for voltage drop. Motor loads like ACs you can have an over sized fuse for the conductor.

So would you mark the panel box or wire at the breaker like zulu kona said to make sure that it was known there was a lighter gauge wire in the circuit? Also as I understand that 14 will handle 20 amps just fine, but is not technically recommended.

There is no requirement in the NEC to do that. In a home maybe a good idea. Commercially were this would happen the most it's never done. NEC lowers the rating of #14 to 15 amps.

[Stovie]

Sort of OT, how does the line voltage factor into the power bill? I've noticed the average voltage in the area has crept up over the years. Utilities are buried, and after they redid everything recently the line voltage is 125 to 126 volts. I remember reading numbers (in books) that line voltage in the US is 110, 115, 117, 120 ... Can see a pattern developing here!

Higher voltage = more current = more $$ on my bill? I dunno. I've heard AC motors definitely don't like sag.

[mksmth]

Sort of OT, how does the line voltage factor into the power bill? I've noticed the average voltage in the area has crept up over the years. Utilities are buried, and after they redid everything recently the line voltage is 125 to 126 volts. I remember reading numbers (in books) that line voltage in the US is 110, 115, 117, 120 ... Can see a pattern developing here!

Higher voltage = more current = more $$ on my bill? I dunno. I've heard AC motors definitely don't like sag.

Appliances typically run more efficient with increased voltage but your example won't really help. An AC running on 208 v 3 phase will pull more current than one the same tonnage but using 480v.

[MYN927]

Connections will loosen up or 'relaxed' over time. That's because you've got something called 'metal creep' and things get deformed permanently after being mechanically stressed for a while. They are accentuated further by heating on instances where current draws are relatively large. It gets worse if there are repetitive heat-cool cycles. The 'mechanisms' are different but they do add up with each other and eventually result in a loosened connection.

[Ridge_Runner]

Sort of OT, how does the line voltage factor into the power bill? I've noticed the average voltage in the area has crept up over the years. Utilities are buried, and after they redid everything recently the line voltage is 125 to 126 volts. I remember reading numbers (in books) that line voltage in the US is 110, 115, 117, 120 ... Can see a pattern developing here!

Higher voltage = more current = more $$ on my bill? I dunno. I've heard AC motors definitely don't like sag.

Basically, those voltages are all in the nominal 120 Volt classification in the US. However, it is common to have different measured readings depending on the characteristics of the electric distribution in a given area, even so over the course of the day.

>>Higher voltage = more current = more $$ on my bill? ...

Eh, it's not quite like that, higher voltage will actually result in lower current. Aside from all the junk we keep plugging in, the biggest thing I see affecting my electric bill is the ever-increasing generation and distribution charges.

[Phredd]

The current in my house and shop can vary from about 114 to 121. Not sure why. I do live in a older neighborhood with most homes built from the 1920-1950's.

[Gunhippie]

Thanks for the replies, gentlemen.
All solid copper 12-2 and 14-2 romex.
The idea is to re-use lengths of wire from circuits I removed
previously, plus add in a couple of lights using 14 gauge,
which is obviously cheaper and waaay easier to work with
I guess "adding" a circuit isn't really what's going on here.
I'm more like re-configuring and extending one.
It already comes out of the panel and to the first J-box as 12 gauge, so I'm leaving that.
I'll write on the wire in Sharpie that the circuit has 14 gauge wire on it.
Not worried about code, no inspector will ever see this while I'm alive.
I trust my own work more than some licensed electricians I've known.

Your last sentence is so very true. My dad was an electrician for the county, lots of stories where things like like union electricians buildings a new school were behind so they just put receptacles in without attaching the wires, about half of a new school. I helped a community center with a kiln once that I swear was trying to burn the place down to get insurance money. Their "licensed" electrician wired a 60 amp circuit for an electric kiln, I had to turn the receptacle over to relieve the tension on the wire and found that he didnt tighten the lugs down, the wires just fell out.

I'm glad I've had good craftsmen in my life to teach me how to do most things and to always double check others work.

Easy to make assumptions like this, but often and especially with high draw circuits that heat up alot, the expansion contraction will cause wires to loosen up. Whenever I install panels that I know will have high demands, I’ll ask my customers to have me back in 6-12 months to retighten everything.

Reistive loads--heaters, water heaters, ranges, etc are notorious for this. When we used 108 kW of 6 kW heating elements to heat our brewery water, I found myself tightening every connection once a month or more. A even slightly loose connection would start heating up and burning the insulation off the high-temp, over-sized wires.

[mksmth]

The current in my house and shop can vary from about 114 to 121. Not sure why. I do live in a older neighborhood with most homes built from the 1920-1950's.

things that can effect voltage changes are load, distance and sometimes bad connections. If you happen to be at the end of the line and the load increases you could get fluctuations in the voltage. However If you are having fluctuations that much you might want to call the power company and have them check their transformer. I had one customer that kept having electronics fry because he would occasionally get spikes above 130v. Ended up being a bad transformer.

[Gunhippie]

The current in my house and shop can vary from about 114 to 121. Not sure why. I do live in a older neighborhood with most homes built from the 1920-1950's.

things that can effect voltage changes are load, distance and sometimes bad connections. If you happen to be at the end of the line and the load increases you could get fluctuations in the voltage. However If you are having fluctuations that much you might want to call the power company and have them check their transformer. I had one customer that kept having electronics fry because he would occasionally get spikes above 130v. Ended up being a bad transformer.

If your house feed--the line from the transformer to the house panel--or panel are undersized, this can be caused by varying loads in the house. If so, it's a potentially dangerous situation as lines/panels that are that overloaded have a tendency to get hot--really hot.

[mksmth]

The current in my house and shop can vary from about 114 to 121. Not sure why. I do live in a older neighborhood with most homes built from the 1920-1950's.

things that can effect voltage changes are load, distance and sometimes bad connections. If you happen to be at the end of the line and the load increases you could get fluctuations in the voltage. However If you are having fluctuations that much you might want to call the power company and have them check their transformer. I had one customer that kept having electronics fry because he would occasionally get spikes above 130v. Ended up being a bad transformer.

If your house feed--the line from the transformer to the house panel--or panel are undersized, this can be caused by varying loads in the house. If so, it's a potentially dangerous situation as lines/panels that are that overloaded have a tendency to get hot--really hot.

Loose neutrals can cause some funky readings too. Found lots of those at weatherheads.

So this is funny. I keep getting these home electrical warranty letters from our power company. They are trying to get people to pay them $5 a month to warranty our electrical services. I keep writing back saying no worries i can fix it if needed. But now I think thats cheap if I dont have to mess with it LOL

[Ridge_Runner]

The current in my house and shop can vary from about 114 to 121. Not sure why. I do live in a older neighborhood with most homes built from the 1920-1950's.

things that can effect voltage changes are load, distance and sometimes bad connections. If you happen to be at the end of the line and the load increases you could get fluctuations in the voltage. However If you are having fluctuations that much you might want to call the power company and have them check their transformer. I had one customer that kept having electronics fry because he would occasionally get spikes above 130v. Ended up being a bad transformer.

If your house feed--the line from the transformer to the house panel--or panel are undersized, this can be caused by varying loads in the house. If so, it's a potentially dangerous situation as lines/panels that are that overloaded have a tendency to get hot--really hot.

Loose neutrals can cause some funky readings too. Found lots of those at weatherheads.

Yea, a fluctuation of a few volts is pretty normal, but 114—121V is a good spread.

It wouldn’t hurt to look into it. The power company should come out and check their equipment no charge. If they don’t see anything odd, having an electrician give your service an inspection would be a good thing, peace of mind if nothing else.