Electrical Question

[George Bokros]

I am going to be installing some led lighting above our kitchen cabinets. I will have 12 ga romex coming from the wall switch and the led power supply has 18 ga input. Is it safe to run 18 ga standed wire ~36" from the 12 ga to the 18 ga input on the power supply?

Thanks

[Bruce Volden]

I would think it to be more than "safe".
My question would be why are you using 12g for lighting.

Bruce

[George Bokros]

My question would be why are you using 12g for lighting.Bruce

Because I am connecting them to a circuit feeds outlets that are wired with 12 ga from breaker to outlet.

[Bruce Wrenn]

Your lights most likely have a UL label on them. This means what they are doing has been deemed safe. All fluoresent lights use such a system

[Jason Roehl]

Get some of these--will make future replacement even easier:

https://www.homedepot.com/p/Ideal-102-Model-PowerPlug-Luminaire-Disconnect-25-Pack-30-372/303741498?cm_mmc=Shopping%7CG%7CBase%7CD27E%7C27-11_TOOLS_%26_ACCESSORIES%7CNA%7CPLA%7c717000000342 38984%7c58700003943782712%7c92700031954542200&gclid=Cj0KCQiA3IPgBRCAARIsABb-iGKK7leJ2kzTa09QWjQdCOzFw3R0xZsMrRCf_QAbFkpL2DROdL sGQzQaArayEALw_wcB&gclsrc=aw.ds

[Kevin Beitz]

The only problem I see is if you get a short in your 18 ga standed wire the circuit breaker on the line might not trip. The 18 ga wire could get hot enough to start a fire. You could put in a small 10amp breaker at the end of the 12ga. wire.

[Rod Sheridan]

Yes that's fine, most devices you plug in such as a radio, clock etc have 18 AWG cords.

The only issue may be if you're feeding the lighting from a dedicated kitchen receptacle as defined in the electrical code. Where I live the circuit cannot be used for anything except the receptacle...............Regards, Rod.

[Bob Grier]

I am not an electrician but I agree with Kevin. I am assuming that most appliances have a fuse to protect against their leads overheating if there is an internal short in the appliance. I have always wondered about how to protect if there is a short in the leads. In the case of fixtures, the house conductors are connected to the fixture leads inside the fixture box so the short circuit is contained. In your case if the leads are connected to the house conductors outside a splice? box or they run outside the box after connecting to the house conductors then I don't know what is protecting those 18 ga wires unless you install an appropriate fuse in the splice box. Maybe the short doesn't create enough energy to cause a fire, I don't know.

When I installed over the counter LED kitchen lighting I hard wired the house conductors to the the LED transformer and used metal conduit to the transformer. Maybe my system was different than yours and what I say doesn't apply.

[Art Mann]

I am not an electrician either but I am an electrical engineer. I spent a several years designing automotive circuits that incorporated overcurrent protection. All of these were tested to failure many, many times. I can say with some authority that the probability that a short of an 18AWG wire would not trip a 20A circuit breaker is very nearly zero. I could say the same thing about a 22AWG wire. As Rod already mentioned, if you are afraid of connecting 18AWG wire to a circuit with 12AWG wire, then you should immediately unplug every floor and table lamp in your house.

[George Bokros]

Thank for all the replies. My thinking was the same as what Art highlighted. It is comforting for this retired "Bean Counter (accountant)" to get consensus from someone that is knowledgeable in this area.