This is for a walk-in closet that will have lighting in each individual closet unit. The lights in each closet unit will be connected to a wall plug.
First question: Is there any reason I can't have all the outlets wired to be controlled by a single smart switch so I can control all of the outlets w/that one switch? Actual on/off via local control, not via the hub. Most of the time the lights will be managed via hub motion/contact automations (switch will be left in the on position) but also want the ability to turn the power to all the lights on/off via local control for special cases.
Second question: To calculate the load on the switch it is simply adding up the wattage of each unit's set of lights, correct? So if there are 7 units, and if the rated watts for the lights for each unit is 45 watts, 7x45=315 watt load, so at that level I'd need a switch that can handle a >315 watt load.
Have I got that right? Please tell me it's all that simple.
You select switches based on their current handling capacity, not power. So you'll just need to do the extra calculation (or get that from the light specs) to determine what maximum current your lights will draw and if this exceeds the rating of the switch. This is just a broad brush calculation which should generally suffice if you leave enough headroom.
Just wondering if there might be an electrical code issue with one switch controlling 7 outlets.
In theory each outlet might someday have a heater or hairdryer or ?, drawing high current through that switch when someone turns it on/off.
Is that a thing?
While that seems rational, in reality, the in rush current during startup with different types of loads can vary quite a bit. Based on load in-rush differences, smart switch manufacturers (@danabw is looking for a smart switch) have limits based on the type of load.
For example, here are the specifications for the Zooz Zen21 switch:
A 315 Watt LED load could exceed the relay's rating - especially if the LEDs are old, and it takes a lot of in-rush current to get them going - much like Dana and me
Without more specific details to the contrary, 315 w load on switch should be fine. A mechanical with for 15 amp rating would work. On the above example from aaiyar you can see the capacities have already been derated. The 960W Incandescent load max versus the 1800W resistive rating takes into account of inrush current. Thats because an incandescent filament, when cold (off) has very little resistance allowing a high surge in current. (That's why most of the time a bulb fails it "pops" right when you turn on the switch) As the filament warms up (on) the resistance goes up and the current demand goes down.
I would also be very concerned if you wire a switch to seven different outlets at once.
I was wondering about code issues that might limit the number of outlets one switch can control. Other uses (hair dryer) his should not be a concern about hair dryer as the outlets will only be used for lighting in the closet.
First you should be concerned about total load as @Ranchitat pointed out. If you have a large room and lots of things plugged in, what happens if someone comes in and plugs in a vacuum cleaner? most likely an overload. This would be probably a circuit breaker tripping unless you have the misfortune of turning off the switch while the vacuum cleaner is running causing an Arc across the switch.
A further concern may also be local building codes. Since the codes are mostly local I would probably ask a local electrician.
Yup...talking to the electrician who's going to do the work is the next step. I was just trying to get some smart-switch specific info (assuming there was any) before I talked to the electrician. No idea what his experience is w/smart devices. This is part of a permitted remodel so we will be doing things to code.
I recall a number like 8 receptacles max on a 15 amp breaker. If your switch is rated for 15 amps then I can't see an issue.
There is some NEC text stating there should be a light switch in every room. Not sure if a closet is a room.
Regarding someone plugin in a hair dryer into one of the outlets. That's irrelevant to the switch question. Somebody can always over load a circuit. Like a window A/C + a vacuum cleaner.
Thanks...I still want local control from the switch to be able turn all the outlets on/off, and the LED strips themselves are zigbee so I have hub control over them from that perspective.
