Here is a highlighted image of a random electric dryer schematic.
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Notice that all the control circuits are 120V components, and that basically only the heater is 240V. Extending this image further, we can see how the dryer connects to a 120/240V split-phase system using a 3 wire cord.
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Due to the nature of the 120/240V split-phase system, the grounded (neutral) and grounding conductors in a dedicated single appliance circuit are basically the same. The dryer will work just fine whether the N
terminal is connected to a grounded (neutral) conductor, or a grounding conductor. However, connecting a NEMA 14-30R device in this way is nonstandard, and a code violation.
NEMA 14-30R
In the case of a three wire circuit, a NEMA 10-30R device should be installed.
NEMA 10-30R
When the wiring is connected to the proper device, the third wire in the cable becomes a grounded (neutral) conductor, and the code may be satisfied.
If you read point number three of the exception to section 250.140 of the National Electrical Code, you'll find that the neutral must be either insulated, or part of a Type SE cable. If this is not the case, your installation may still be a code violation.
An uninsulated, normally current carrying conductor running through your walls is typically a bad thing. Which is why this code exception is only valid, if the conductor is insulated.
tl;dr
Connecting a dryer in this way will work, but is a potentially dangerous code violation (according to the National Electrical Code).
If the receptacle is not of the self-contained variety, and is not in a box. That is defiantly a code violation (NEC 2011 406.5).
Extra Information:
If a proper 4 wire cable existed, the schematic from above would look something like this...
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If I've missed anything, or haven't explained something properly. Feel free to ask additional questions, or point out mistakes in the comments below.
First off, I would get approval from your landlord before making any wiring changes to your apartment. You never know, he might be friendly enough that he would hire an electrician to make the changes you want.
I would first attempt to figure out how the receptacles are wired to the switch. If there is a way to separate them, then I would do that.
If not, then I would bypass the switch and just make everything permanently on. then just use your wireless bulbs and remote app. You should be able to replace the switch with the wireless switch, but make sure it works with your bulbs.
Best Answer
Locking Receptacle Cover
Use something like this locking cover:
It has a hole for a padlock. Lock it when you're away. Unlock when you need it.
This particular one (and many others) specifically weatherproof for outdoor use since that is a common application - prevent your neighbor from using your electricity - but it will work fine indoors too.
This is also an in-use cover. So you could have a device plugged in even while this is locked. For example, you could have an appliance that should stay plugged in while keeping the other receptacle of the duplex from being used.