Ok to branch a 120V receptacle from a 240V junction box?
About to install cabinets for kitchen remodel. I have a tall cabinet that will house a wall oven and built-in microwave. I’ve already roughed in a 240V junction box for the wall oven. Is there any reason why I can’t tie into one leg of that circuit to create a connection point for the microwave? Any feedback on this would be appreciated.
Michael
Replies
Three issues,
1. Is there a neutral present? (it should be)
2. How will you limit the 120v circuit to 15 or 20a?
3. Will that overload the circuit?
If you are not actually installing the oven you can put a 20a 2 pole breaker in there, and install two 120v circuits.
The oven will be the deal killer tho.
You really need another circuit
Sounds like I'm gonna need to upgrade the electrical.
Existing cable is 6 gauge, 3 conductor. Existing breaker is 40A. I haven't purchased the wall oven or the built-in microwave yet. I just want to be sure I've provided sufficient means for connecting them when I do.
In general, no, you can't do it, because there is not sufficient provision for overcurrent protection of the microwave.
So what about a combo unit?
I think I understand what you're saying. So how about an oven/microwave combo unit instead of two seperate appliances? I've got 6-3 cable with ground. I realize that a lot of this is relative to appliance specs, but I wouldn't think the typical combo unit would require more than 50-60 amp protection. Am I wrong in assuming I could upgrade my breaker with this cable, provided that the combo did not spec something larger than that? I'd edstimate the existing cable length to be 30 feet maximum.
BTW, thanks for the feedback.
So long as the combo unit doesn't require a separate service for the microwave (the couple I checked don't), and so long as the existing cable is 4-wire (2 hots, neutral, ground), and so long as it's of sufficient size to handle the load, then it should work.
Thanks, Dan.
I haven't been around in quite awhile, Dan. Good to know you're still sharing your wisdom.
I called mine a 3 conductor cable, but I was speaking of 3 conductors and a ground. It's definately two hots, neutral and ground. I don't always know the correct lingo. Thank you for weighing in on this, also. I'm getting ready to place some cabinets and I want to make sure I've adequately addressed all the mechanicals before I do.
Maybe I'll just shop for a combo when it's time to purchase applainces. I would have preferred to keep those two appliances seperate, but I sure hate to pull another circuit just for the microwave. I've been remodeling for six years now and I'm so friggin tired. I just want to be done with it.
It's always something.
When writing here I always specify the specific wires, vs, eg, 3wg, since many folks don't understand the notation. 3wg is fine.
Put in a sub panel one that will take a 2 pole breaker and 1 or 2 singles. A 30 will be plenty for 99% of wall ovens but you can use a 40and put in a 15a or 2 (single pole) for "fixed in place" appliances. 6ga can take a 55a or maybe even a 60a using the round up rule.
The 15s can't be used for "small appliance" circuits you need a 20. but a fixed in place MW is not a SA circuit.