Hi
I am replacing all of the appliances in my kitchen.
Currently I have:
- cook top – attached on 220V, 2x40A beakers
- oven – attached on 220V, 2x30A beakers ( red, red, white wiring)
- fridge – attached to the outlets on 110V, 30A beaker
I am buying:
- slide-in range – I will attach it to the old cook-top wiring
- dishwasher – “15A, 110V” required
- microwave – ‘15 OR 20 A, 120 Volts’ required (1.2kW)
- fridge – ‘15 OR 20 Ampere, 115 Volts GROUNDED CIRCUIT IS REQUIRED’
- garbage disposal

The question I have is what are the optimal, save, and legal electrical connections. I am planning to convert the 220V (3x30A beakers) into 2 x 30A x 110V and I have an extra 30A beaker for the outlets. I don’t want to install new breakers.

Choice 1
– dishwasher + garbage disposal on one 30A breaker
– microwave on the second 30A breaker
– fridge attached to the countertop outlets – 30A breaker

Choice 2
– dishwasher + garbage disposal on one 30A breaker
– microwave + fridge on the second 30A breaker

Choice 3
– dishwasher + microwave disposal on one 30A breaker
– garbage disposal + fridge on the second 30A breaker

Any other suggestions?
Thanks
DJ

Since the appliances will be using all standard 15 or 20 amp receptacles, you are not able to use the existing 30 amp breakers. You need to have at least two appliance 20 amp circuits in a kitchen just for the counter outlets. The fridge can be included in these circuits. The DW,disposal, and microwave should be considered as stationary appliances and are in addition to the appliance circuits.

Using all #12 wire and 15 or 20 amp devices and 20 amp breakers, use one circuit for the frige and one counter outlet, one for the DW and disposal, one for the microwave, and another for one more circuit for counter outlets.

Using 30 amp breakers is not standard and never done and is not allowed for what you proposed.

Hi tk
Thanks for the answer. Seems that I can not use the existing 30A breakers for the purpose. My original kitchen is very old and this is that’s why they used 30A breaker for the kitchen outlets.

I have the following question. Seems that I need total of 4 x 20A breakers to complete the rewiring. Is it possible to use the existing wiring for the 3x 30A breakers (the wire seems to be thicker than #12) and replace the breakers with 20A to match the receptacles. And I will need to add only one extra circuit/breaker?

Thanks again

As far as the wire size, need to be sure what size it is, and insure you have at least #12 wire to these appliances and outlets. You can get a wire stripper that will have a wire gauge builtin at any hardware/tool store.

Yes seems you will need one additional 20 amp breaker and circuit.

Hi Tk
Thanks a lot. You seem to be an expert and I hope you don’t mind if I ask you a last question.

As you can guess the kitchen is old ~40+ years and the wiring is done without ground wire (hot + neutral only). I would like to ground all of the kitchen circuits – outlets and appliances. Is it OK to do this locally (only in the kitchen) by grounding everything to the nearby pipe. For example use #10 wire and ground everything to a single spot. My 220V uses 3 wires (red/red/white) and I want to use one red, one white and ground for the two new 110V circuits.

Thanks

Sorry, no short cut here. If you want, and really should since you are remodeling, all the outlets and appliances grounded, then all new cable that has a ground wire, such as Romex, technically NM-B cable, needs to be installed.

What you proposed is not allowed.

The 240 volt cable idea is fine, but only for one 120 volt circuit, the 3 wires will get you 1 hot, 1 neutral, and 1 ground. Not sure how you plan to get tow circuits with only 3 wires, of course, unless you plan with no ground.

Yes I can consider myself an expert. Been working in the electrical field since 1972, worked my way up from apprentice to a Licensed Master electrician in two states, and a State Certified Electrical Inspector, along with being an insurance inspector. Haved wired more homes than I can count, from 750 sq ft bugalows to mansions, and 400 unit luxury apartment buildings, supermarkets, malls, strip plazas, high rise office buildings, and from light to heavy industrial plants, IT data centers, on, and on and on.

For the last several years I have been involved with the more scientific approach to electrical service by doing inspections and surveys of power quality, preventive maintenance using hig tech instruments such as infrared cameras, ultrasound detectors, and many other "toys". To find and solve problems before they become disasters.

In a nut shell, I know some stuff.

I will only tell you the way it should be , to conform to code, and to be safe and secure with the wiring that is done. It is your home, some things I say may not be agreeable, so it is your choice to do whatever you think is best.

And I do not mind, ask as many questions you need to get it right.

Hi tk
Seems there is no easy way out, if I want to have the grounding done. Even for the new range “ELECTRICAL GROUND IS REQUIRED”, so seems that I have to pull a new 4-wire’s cable (currently the two 220V circuits have 3 wires) or a separate ground wire.

Just to make sure I understand what you are saying I will repeat what I am going to do, and please let me know if there is any problem.

- use new NM-B 3-wire #12 cables for the 20A circuits.
- install 4 x 20 A circuits / breakers
- microwave
- fridge + one outlet
- DW + GD
- more countertop outlets
- pull a single ground wire just for the 220V range
- connect all green wires from the cables ( 4 greens) and the ground from the 220V to the neutral line in the junction box (I assume that this is the correct place to ground all electrical circuitry in the house. Let me know if this is not coorect)

I am an electrical engineer myself, but working in a ‘micro’ world of IC’s. I think I can handle the job of wiring my kitchen, but just want to make sure that I follow the building code and is safe.
Thanks again

OK, just a few clairfications:
The 3 wire is called 2 wire and the ground is understood, or call it 2 wire w/ground.

No single ground wire allowed for the range either.

All the cables, with grounds need to be brought back to the panel. If the panel has a main breaker/fuse in it, the grounds and neutrals all connect to the main neutral bar, if the main is remote, outdoor for example, then the neutrrals only connect to the main neutral bar, and the grounds need to connect to an equipment round bar that is bolted directly to the panel back box.

IC chips, now you got me, I have no clue.

I am completely confused about the terminology then. My 220V has 3 wires – red/red/white. I know that the two reds are 110V each w.r.t. to the neutral, but out of phase to each other. Thus they add up to 220V. I assumed that the white is called neutral, but what you are suggesting is that it is actually ground as there is no current flowing through it (all of the current is drown through the reds). If this is the case, then the circuit is actually grounded and I don't need to pull an extra wire or reinstall it. Is that correct? The requirement for the range is “40 Ampere, 120/240 Volts, 60 Hertz (1/second). 3-WIRE OR 4-WIRE. ELECTRICAL GROUND IS REQUIRED”

My panel has a main breaker and is located outside the house, but on the side of the stucco. I think is grounded , because I can see a thick bare copper wire (probably #8) connected to the neutral and going down, most probably to the ground. I guess I can buy a tester to verify if it's grounded.

Is the cable with the two reds and one white the cable that is part of the range? What exactly is this cable? Is the cable a metal type? If so the metal raceway can be the ground, and the white is a neutral.

Are you measuring 220 volts?

Is this in the USA? Canada?

Lets get through this, the 3-WIRE OR 4-WIRE. ELECTRICAL GROUND IS REQUIRED will then get explained, if I try now it will only confuse you more. I need to get a better idead the type of cable and where your located.

Yes if the main breaker is at the meter, the you should see that ground wire.

This means the any neutrals need to be separated from equipment grounds in the panel.

I am located in USA in CA. Currently in the kitchen I have two 220V circuits. My initial plans were to use one of them for the new range, and the second to convert to 2x110V for the DW and Microwave. At the end we decided that I have to pull new wires, because I don't have a ground wire. I did not measure the voltage either.

Both 220V circuits have 3 wires each – two reds and one white per circuit (I don't see them to be part of a single cable - they are separate). As far the cables are visible - I have a metal junction box below the cook-top, and I have metal raceway (tube) running from the junction box to the old cook top and another to the old oven. I am not sure what is behind the wall, i.e. if the metal raceway continues to the junction box.

“This means the any neutrals need to be separated from equipment grounds in the panel” – I am not sure that I understand what you mean. In the moment I can see that all neutral wires are connected to a the neutral from PG&E and I can also see that there is a thick bare copper wire connected to the same spot and running down (most probably ground).

Can you provide some pictures?

I just cut s small opening in the dry wall to see what's behind. Here are the pictures:

Picture 1 –the junction box below the cook-top. These are the 2 x 220V circuits. I have two black and a white (left) going to the cook-top and two red and a white going to the oven (right). All six wires go into a metal tube, which goes down to the crawl-space.

Picture2 – this is the cut in the dry wall below the junction box of picture 1. All six wires go into this metal tube to the crawl-space.

Picture 3- the main box located outside the house (on the sidewall). Bottom 4 breakers are for the 2x220V circuits above ( 2x 40A – black wires and 2x30A red wires). Top green are 2x100A Main breakers. On the left are all neutrals connected to the neutral of the main power supply. You can also see the thick bare copper wire connected to the same bar, which I assume is the ground.

Picture 4 – a close up of the bare copper wire on the left

Picture 5 – all six wires from the 2x220V circuits above go through this opening into the junction box (not very clear, close to the right of the picture). It’s located in the bottom right corner. To me it looks to be a plastic pipe and a plastic screw but could be wrong. If it’s a plastic, then the pipe does not seem to be grounded to the metal of the junction box (unless is done inside and I can not see it). To be grounded, the metal pipe protecting the 6 wires, could be connected to the ground somewhere in the crawl space or to the main junction box, but I can not see it.

OK great, pictures tell a thousand words. Your system is done in EMT, the metal tubing you see in the walls. This raceway is the equipment ground, the white is the neutral.

So, you can use the two reds and the one white as two 120 volt 20 amp circuits with a shared neutral. Connect and greens or bare grounds directly to any outlet box, the EMT will provide the equipment ground back to the panel.

If you run any new cable, use BX or MC, with BX the sheathing is the ground, MC will have a green wire. Any green wire or bare brought back to the panel connects to the Main Neutral bar, because the Main Switch is in the panel. Be sure all cable and conduit connector locknuts are tight everywhere, as the ground relies on the continuity of the these being tight.

The two dark green breakers tied together at the handles I believe is the Main Switch. Is it rated 100 Amps? Sure looks like the Main.

Are they Zinsco breakers? I don't see those very often, just not popular here on the East coast. They are available from surplus breaker suppliers, can find many of these suppliers on the Internet, if you need any additional or replacements. If the two pole with the two reds is a 30 amp, then you need to find two single pole 20 amp breakers for the two reds.

Yes the thick bare copper wire is the Grounding Electrode Conductor that goes out to the ground rod and is Grounding the Main Neutral. This is connected here in the panel because the Main Switch is here.

See if this info helps, if not get back with more questions.

Definitely helps… thanks a lot. I think everything makes sense now. The breakers are Zinsco.

One concern though is that I don’t see the neutral for the 50A 220V for the drier (the largest breaker in the middle). What I think is that the thick bare copper wire may not be the grounding but the neutral for the drier and that the main junction box is not grounded. I will figure it out.

Once again thanks for the help