In my kids’ bedroom, there is fan and 4 light lamp attached to the same fixture. There are two pull strings 1 for the fan and 1 for the lights. There is one switch which controls the power to both. I want to replace the switch with a smart switch but if I turn off the switch, both the lights and fan goes off. How do I get it to only turn the lights off
Hi @Arun_Nayar.
You need to control each separately. I used a GE Fan Control switch for the fan and an Aeon Micro Switch for the lights.
Also, be very careful connecting a fan to a switch, especially a dimmer! If you use the wrong type of fan control you could start a wall fire.
Here was my approach to this:
Aeon Micro Switch DSC27103-ZWUS to control the lights
GE Fan Control 12730 to control the fan
This setup assumes that you have line, neutral, ground and separate pairs of wires for the fan and lights in the switch box. There are other ways to handle this (like having the Aeon Micro Switch up in the fan canopy), but this should give you the general idea.
I dont think I have separate wires for fan and light which is the whole problem.
So basically you want to leave the fan running and have the wall switch control the lights. I would put a regular smart switch in the wall and wire it just to be a dummy switch and run constant power to the fan and lights. There should be room to put the micro switch in the light housing. Set the dummy switch to control the micro switch and now you have control over your lights without changing the state of the fan. You would still need to manually pull the chain to turn the fan on or off.
Similar situation here, but used a ge Switch (non dimmer) to control the light from the wall and then used a aeon micro going to the fan from the ceiling. I can control both, but still have to use fan control to lower and increase the fan speed. However I find that leaving the Fan on Medium works for my family.
Wire a dual relay like the monoprice or enerwave one, in the canopy so it has one leg to fan, the other to light. Then wire a dumb switch to the two conductor going down to the light switch, but wire it instead to one of the relay triggers, lights would be my guess as best. Then the light switch no longer has “power” and only switches the light relay, the fan is then remote controlled via whatever you want. Suggest a minimote or button device next to the light switch. Then get rid of the ugly fan pull chains! 
Edit: Oh and then you are only buying the one device for it instead of a micro switch and smart switch.
I would not try varying the speed with this setup… then again, I wouldn’t do this at all, but that is me.
Are you referring to my method or any of these in general? My method would still allow speed changing via the pull chain, with no consequences to anything else that I’m aware of. And since the relay module is in the fan’s electrical box/canopy where current already comes in, it’s no different than having it behind a switch.
Are you concerned about the fan’s motor resistor when you set a lower speed heating up?
Yes, my concern would be to vary the motor speed based off of a relay, as opposed to a fan control.
Maybe I am just paranoid. 
The relay’s are rated far higher than the fan would ever draw. The entire point of a relay is to switch a higher powered line via a lower powered one. A three speed fan, which I dare say if the most common, has either a multiple winding motor that the switch selects a different winding per setting, or a resistive switch IN THE FAN that increases resistance for 2 of the three speeds.
What you are concerned with is what happens when you put a traditional light dimmer on a fan and expect to vary the resistance in the light switch to control the fan. If the light dimmer is resistive, it’s already set up to handle the heat dissipation a lower fan speed would need. Since a fan uses less power than a 60watt bulb, this should be a non issue. Obviously if using a dimmer with a fan you’d keep the fan’s internal switch set at it’s max speed so that wouldn’t come into play, having a lower speed set however would cause a more resistive load to the dimmer possibly causing issues, but that would be stupid.
I have no basis in real experience to say this, but the thought of a fan on a light dimmer causing a fire seems like a myth to me.
I’ve seen relay’s switch WAY more than 110v @ a few amps and not burn up. The internal structure of a relay is such that when a low voltage is applied to the relay, an electromagnet pulls a switch that would be just as robust as it’s rated for, between the load and feed legs. There will be a small increase in resistance between the materials, just like a wire nut screwed onto two wires, but nothing that would cause a fire.
I’m not an electrician (my brother is, but I didn’t ask him) so I’m in no way going to say I’m right, but I have dealt with lots of electrical stuff in my life. So hopefully I will be critically rebuked if I’m off base by someone more knowledgeable than myself!
Edit: You did get me thinking and I found this explanation, I just can’t see why someone would want to have a fan speed control at switch level, my moms house had this and it bugged the crap out of me tbh.
A dimmer will reduce the wattage to the fan motor meaning that you are increasing the impedance over time, meaning that heat will buildup until it becomes a potential fire hazard. This is the same reason that you shouldn’t use a normal dimmer switch for incandescent bulbs as they have a large initial current draw.
Edit 2: Did ask my brother, he gave me a quick reply:
The load is inductive not resistive. I’ve never heard of fire danger. Just loud and poor performance. You just have to get a different type of dimmer.
So…use a relay and the fan’s built in three speed. 