Help with DIY dedicated circuit

Your stove should be on a 40 amp circuit, which requires 8/3 Romex cable. Change the breaker from the 40 amp twin breaker to a 20 amp twin breaker then make the stove receptacle box a junction box where you splice some 12/3 Romex to the 8/3 Romex and then run the 12/3 to a duplex 20 amp receptacle with the tie on the hot side removed. This will give you two 20 amp receptacles. 

It is definitely a 30 amp twin breaker with 10/3 (orange) Romex. Do I need to change it to a 20 amp breaker? Is it ok to use the 10 gauge wire with the 20 amp breaker to a 20 amp Porter Port outlet?

You can use 10/3 with a 20 amp you can always go larger gauge but never go smaller. 

So I will change the 30 amp twin breaker to a 20 amp twin breaker. If I install two 20 amp Porter Port outlets and use 1 hot of the Romex 10/3 to each outlet (red and black) sharing the common white wire, will that defeat the purpose of having 2 dedicated 20 amp circuits. By the way, the stovetop was a cheap radiant electric cooktop and was a piece of crap.

A word to the DIYer re: DIY electrical mods

check with your insurance company first...

You may require a licensed electrician sign off or risk voiding your insurance policy.

If you have to ask how to connect wires within a junction box I’d suggest getting professional help.

Best of luck


Peter 

You're not suppose to use the same neutral wire for 2 seperate breakers you can for a double pole since any overload on the neutral will trip both. 

You also need to make sure the new 20amp  double pole is on different phases in the panel box. It should be if the old 30amp was installed correct. 

pbnaudio....the physical wire connections are not what I'm asking about. I am comfortable with that. I'm asking whether to use the 30 amp twin breaker and the 10/3 cable that is currently in place (too short to reach wall outlet) with a piggytail from a junction box I'll install to the outlet, or I'll have to pay significantly more to have an electrician run a new 20 amp line from the panel to the wall. Also, could I install 2 independent outlets without running a separate cable since there are 2 hot cables with the 10/3? It appears best to change the 30 amp twin breaker to a 20 amp breaker since it will be serving a 20 amp rated outlet.

Not sure if it was suggested, but you could run 12/3 and have 2 separate 20 amp outlets. :) Get an electrician to do it.

If it were me, I’d use 15 amp breakers with spark detectors. You don’t need 20, and 15 will be safer. There’s no audible difference. Also while there ask the electrician about a whole panel surge protector.

Also, in some high-heat areas, you may need to underrate your wiring anyway.


Best,
E

I also recommend an electrician.  One of the comments indicated to make sure both of the "HOT" wires to your two new outlets are on the same phase.   Your stove ran on "220/240 Volt" which means that, in the United States, the two "HOT" wires are just 120V that are out of phase.  When you wire these to the stove, the stove uses both 120V in a push/pull configuration.   You really should have an electrician do the work because you want either one single 20A breaker with both "HOT" wires leading out of that.  Or you could install two 20A single that are BOTH ON THE SAME PHASE to connect to your two "HOT" wires  of your romes 10/3.  However, there are definitely electrical codes to follow and I'm not sure of this particular configuration.  So, again, I highly recommend an electrician do the work and discuss the options with you.

Read your own link jea48 it clearly states to use 2 PHASES ,  I suggest you quit giving advice you are past clueless. If he puts 2 20amp breakers on the same phase using the same neutral wire then the neutral could carry 40amps  his 10/3 existing wire is rated for a 30 amp load which could cause the neutral wire to overheat causing a fire. The breakers need to be on seperate phases where they balance and the neutral carries the difference between the loads, on the same phase the neutral would carry the sum of both.  You can use 2 seperate 20 or 15 amp breakers running one hot black and one hot red  and both use the same white neutral as long as those breakers are NOT on the same phase. Code is to use a linked 2 pole breaker IF it's a 240v  single phase OR multi- wire branch circuit with a SHARED  neutral. The OP needs to call an electrician mental is right  to much nonsense to confuse him. 

After all this and watching the YouTube link, I am more confused. If I do the work, I think I will use the 10/3 wire that is in place already, but change the 30 amp twin breaker to a 20 amp single breaker only using one of the hot cables and capping the other on both ends. I'll piggytail either a 10/2 (will it fit in the wall outlet?) or a 12/2 cable from the junction box to only one 20 amp outlet and forget about installing 2 outlets at this time.....or I'll get an electrician....

Pigtail with 12/2 it's easier to use and is fine for a 20 amp receptacle. Most likely the old 30 amp breaker is on 2 phases and you would be fine running 2 new breakers but unless you know for sure do what you said. 

Sorry he deleted his posts it looked as though you were directing it to me as I didn't see his post. I can see I made a mistake going back and reading it again. 

@djones51 is correct in his last post, except for the terminology of phasing. In residential electrical systems, it is actually called “split phase”, which is because the utility supplies only one leg of a three phase feed, via a center-tapped secondary on a step-down transformer, where the center tap is considered the neutral conductor, and bonded to ground at the main service panel.

Thank you mental, that's my plan.

jea48 "Again, what was the last NEC Code edition book you hand in your hands"
It is so funny when one person uses Google to pretend to be an expert meets another person who uses Google to pretend to be an expert and then they both try to convince themselves and the other that he is an expert!

For those who may not be aware, the many posts Jim (Jea48) has provided here over the years about electrician-type matters make it abundantly clear that his background and expertise in this area are second to none. Second to none not only at Audiogon, but I would feel safe in saying among electricians everywhere.

I for one have learned a great deal from his posts over the years, despite the fact that I have a very extensive background in electronic design. And the help he has provided to a great many members here has earned widespread recognition and appreciation.

Regards,
-- Al 

Done! 20 amp breaker. I went with Romex 10/2 from junction box to a single Porter Port outlet which was a little frustrating manipulating the 10 gauge solid copper connections. I decided against 2 outlets at this time since all my gear is connected to a PS Audio P10 Power Plant. Now, to see if I can hear a sound difference.

Nice thread -Jon,
I look forward in reading more about your aural impressions, thoughts, post-installation of 20A breaker and Porter Port outlet.

Happy Listening!

A definite, noticeable, small incremental improvement with the dedicated circuit. I was skeptical because I thought the PS Audio P10 should be able to produce near perfect power from what comes through most any wall outlet. Voices and instruments float a little more distinctly into position and sound-stage is a little deeper. I was already very happy with the sound of my system, so I never expect big changes with these tweaks. I do think it was worth the effort.