Replacing old elecitric range in kitchen with gas range. The existing circuit is 40 amp with 8-4 nm-b cable. New range only requires 15 amps to power clock, light and gas ignitor. Can I simply install a 15 amp receptacle to the existing wiring and circuit? If so do I cut and cap the 4th wire since it us not required? Trying to avoid installing new circuit breaker and running new cable if possible.

 

Basic answer to your question is no. The solution may be simple. Isn't there a counter top receptacle near by you can plug it into?

 

20 amp circuit for microwave oven installed next to range in island. Can I install junction box with another cable run to 15 amp receptacle adjacent to range?

 

Is it a fastened in place microwave or does it just set on the counter?

 

Microwave drawer fastened in place. Install manual for microwave recommends running on its own 15 amp circuit but doesn't say is required.

 

Microwave is 1000 watts. Range no idea since manual doesn't provide detail. However I can't see it requiring much since it only has 2 less, display screen and ignitor.

 

And you have no counter top receptacles in your kitchen? What do you do when you need to plug in a toaster, or mixer, or radio?

 

The microwave and range are located in an island in the middle of room. I designed the island to hide all electric within cabinets because it aligns with contemporary style of the overall kitchen design. Therefore the only b electric going to the island I can work with is the 20 amp circuit hidden with cabinet for microwave drawer.

 

Then probably not code compliant. A 20 amp counter top receptacle circuit was required when built. You will need to add one now. Not Ideal but the existing cable can be used. I assume even though you wrote 8-4 it is 8-3, black, red, white, bare. (8-4 would also have a blue.)

At the island in a 4x4 box cap off the red. Connect #12 pigtails to the black white and bare. Connect the black and white pigtails to the line side of a 15* amp GFCI receptacle. Assuming the box is Metal using #12 pigtail the ground to both the GFCI and the box. (It is unlikely #8 will fit the GFCI receptacle so #12 pigtails are required.)

At the breaker panel remove the 40 amp 2-pole breaker and replace with a single pole 20 amp breaker and a fill plug for the remaining space in the panel cover. Cap the red wire. Using a #12 pigtail connect the black wire to the 20 amp breaker.** White and ground remain connected as before the change. (The neutral and bare fit the bus bar so no pigtail needed.)

*A 15 amp GFCI receptacle is normally used on a 20 amp circuit. Code permits that if two places to plug in and in residential use you are unlikely to have a 20 amp plug.

**A 20 amp breaker not a 15 amp breaker is used to meet the code requirement that was not met when the original wiring was done.

Note: The existing 20 amp circuit is not used due to code for fixed in place appliances which require a dedicated circuit.