Inspected new construction home yesterday. At the bottom exterior of the service panel is a photo cell that controls an exterior light at the garage door. The wires coming from the photo cell go on to a 15 amp breaker, neutral bus and ground bus and are 16 guage wire. It appears that the (spliced) wire from photo cell goes out to the light and is also a 16 guage wire. Does this pose a problem because of the 14 guage minmum size rule or is there some exception for photo cells that I am not aware of?

Thanks,

Eric

If I understand you correctly then:
The photo cell wires are 16 guage
Nothing wrong with that as long as the light or lights it controls will not overload it.

The photo cell is wired to the neutral side
That is wrong. Switches are to be installed so that the power is removed from the light. Switches wired on he neutral side will turn off the light but power is still at the light.

All automatic controls should (must) have a manual shutoff located before the automatic control.
Appliances (lights or whatever) that are controlled by an automatic control must have markings (label) saying so.

Circuit breakers are not suitable to substitute for a switch.

Not sure, but I don't think it is allowed to install the photo cell in the panel.

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Rick Cantrell
Columbus GA

Rick, are those code requirements? (I've yet to see a light labeled per the second portion of that...)

Michael
I cannot say for a fact, however, electric water heater must have, A/C must have. Most motion detection and/or photo cell lights are a single unit, and have a light switch.

Industrial equipment that is automatic has a sigh that states
"This equipment may start up at any time
to be serviced by qualified and authorized personal only"
or something to that effect.

I said "I cannot say for a fact". But I hold a Low voltage contractors license ( burglar /fire alarms, intercoms, video, etc.). It also covers control systems for automatic equipment used in industry (most are low voltage). I don't work on the industrial controls, but I did have to study it in order to get my license.
It is an OSHA requirement for industry, and I would think (hope), required for homes.

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Rick Cantrell
Columbus GA

"At the bottom exterior of the service panel is a photo cell that controls an exterior light at the garage door. The wires coming from the photo cell go on to a 15 amp breaker, neutral bus and ground bus and are 16 guage wire."

That is okay because the photo cell is a listed and labeled unit.

"It appears that the (spliced) wire from photo cell goes out to the light and is also a 16 guage wire."

The 16 AWG coming from the photo cell is okay, however, the spliced on #16 to the light is not, unless (of course) that is the wire coming *directly* from (part of) the light, which is another listed and labeled unit.

If the #16 AWG conductors are spliced to get from point A (the photo cell) to point B (the light), then those conductors would need to be #14 AWG minimum. The photo cell is only acting as a 'powered switch', so it will have a ground, a neutral, and a hot going to it. Then, it will also have a hot (switch leg) coming out from the photo cell to the light. The light will have a circuit containing a ground, a neutral and a hot going to the light. The switch leg from the photo cell connects to the hot circuit conductor to the light. The light will also have a ground, a neutral and a hot.

The photo cell and light are listed and labeled units, and as such, they may have #16 AWG conductors made as part of those units. The circuit (conductors) connecting the two together, however, will need to be #14 AWG minimum.

Now, if the wires coming from the photo cell 'are too short' to reach the breaker and the terminal bars (for the neutral and ground), then *those* circuit conductors will also need to be #14 AWG minimum.

Sounds crazy? Why use #14 to connect to #16 just to connect to #14 just so you can connect back to #16? Because the #16 are 'part of' the listed and labeled units (photo cell and light), while the #14 are 'branch circuit conductors' (which could conceivably be used for another purpose.

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Jerry Peck, Construction / Litigation Consultant
Construction Litigation Consultants, LLC ( www.ConstructionLitigationConsultants.com )

Thanks all for the replies.

The light also has a wall switch that ultimately controls power to the light. I tested it and if the wall switch is not on then the photo cell will not turn on the light.

The photo cell is not "in" the panel per se, but mounted below it with the conductors coming into the service panel.

Jerry,

That doesn't sound crazy but actually makes good sense to me.

Thanks again guys.

Eric