DIY Temperature Control W/Dimmer Switch (WARNING PIC HEAVY)

Here is a little writeup I decided to do on building a device to control temperature using a standard dimmer switch and a few more parts available at any General store for a little under $20. And while some may say that a thermostat is not much more than that. I like the design and would like to share it among friends. I am an electrician by trade so I will do my best to explain the process and hopefully not embarrass the elders to badly.


First here is the list of supply's that I used to build this:

http://i1022.photobucket.com/albums/...psb4f0ba4e.jpg

1. Dimmer switch (I picked mine up at Wallyworld for $5)

2. Replacement cord (also obtained at wally world for around $5)

3. Metal box with outlet & switch cover (picked up at lowes for around $7)

4. Outlet (I prefer the nicer ones that squeeze the wires rather than wrap around)

5. Service cord clamp (around 40 cents at lowes)


List of tools needed to build this:

http://i1022.photobucket.com/albums/...pscbf5707f.jpg
1. Pair of wire strippers

2. Side Cutters (optional)

3. Needle nose pliers

4. Electrical tape

5. Multi screwdriver



Step 1: First thing I did was trimmed down the mounting brackets on the outlet to fit the box a little more conservatively. I used my orange side cutters. It should look a little something like this.

http://i1022.photobucket.com/albums/...ps29bbc12d.jpg




Step 2: Screw the outlet in place on the cover as shown in the pics below. The outlet should now fit in the cover without being to snug if trimmed correctly.

http://i1022.photobucket.com/albums/...ps7911a819.jpg

http://i1022.photobucket.com/albums/...ps9834a458.jpg




Step 3: Open the dimmer switch package, it will need trimming down as well (again I used the side cutters). Trim the dimmer mounting bracket as shown. It will take a little trail and error to fit it in with the outlet, just don't go too much at once. I ended up trimming a little bit off all 4 sides.

http://i1022.photobucket.com/albums/...psfad7a515.jpg

http://i1022.photobucket.com/albums/...psc5ccf538.jpg

http://i1022.photobucket.com/albums/...ps9f957975.jpg





Step 4: Once it fits fairly tight but not cramped, screw the screws in and make sure everything fits. Don't go to crazy the dimmer needs to be removed in order to wire the outlet. At this point it should look like this.

http://i1022.photobucket.com/albums/...psad1aa2ae.jpg





Step 5: Now lets move on to running the service cord through the box. Knock one of the small 1/2 knockouts out with your pliers (I used the middle one). Then install the service cord clamp into the hole and tighten it down with your screwdriver and pliers.

http://i1022.photobucket.com/albums/...ps284cc3ef.jpg

http://i1022.photobucket.com/albums/...ps1115a14b.jpg

http://i1022.photobucket.com/albums/...ps8a546bfb.jpg




Step 6: Run the service cord through about 6 inches and tighten the 2 screws on the sides down to clamp the cord in place. Once that is done strip the black insulation off down to about an inch leaving only the insulation on the black & white wire.

http://i1022.photobucket.com/albums/...ps6579834f.jpg

http://i1022.photobucket.com/albums/...pseaa709b9.jpg




Step 7: Once you have test everything and it all screws in no problems, your ready to wire it up. Remove the dimmer from the cover (the outlet can stay in). Attach the green wire from the dimmer to the ground terminal on the outlet, then wire the white (neutral) wire from the service cord to the silver terminal on the outlet. Silver is always neutral on the outlet, if your still unsure flip it over. The longer prong is neutral. Next wire one of the black wires from the dimmer to the load side (gold terminal) of the outlet. Should stop and mention here that I always use the clamp style outlets with stranded wire as it holds better and keeps the wire from fraying which on a metal box would be bad if one of the strands grounds the side of the box. Lastly wire the only other black wire on the dimmer to the line (black wire) coming off the service cord. Here's what it should look like completed.

http://i1022.photobucket.com/albums/...ps0097e66b.jpg

http://i1022.photobucket.com/albums/...ps6beb35ed.jpg

http://i1022.photobucket.com/albums/...ps6510bd60.jpg

http://i1022.photobucket.com/albums/...ps0f57d455.jpg




Step 8: Tape everything up & check then recheck to make sure no wires are touching where they shouldn't be. At this point go ahead and reinstall the dimmer back into the cover.

http://i1022.photobucket.com/albums/...ps7ebd50ba.jpg




Step 9: Carefully place the cover onto the box taking care not to pinch any wires. Install the 2 screws that hold the cover onto the box.

http://i1022.photobucket.com/albums/...ps9074b07b.jpg






And here's the finished project!

http://i1022.photobucket.com/albums/...ps58957159.jpg

http://i1022.photobucket.com/albums/...ps182cd28c.jpg


I have used these in the past with great success! I know I suck at doing these, I'm sure I'll probably come back multiple times and add stuff I forgot to mention. Just wanted to share with the crew of awesome people on this forum my method for regulating Heat. Peace :D:D

Nice write up!

I love the design, it looks slick, but I'm just wondering, is there any advantage to this over a basic lamp dimmer (under $10), or is it just a nicer appearance?

Curious why you would use a 2 prong cord to run to a 3 prong receptacle?

Quote:

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Originally Posted by Shera

I love the design, it looks slick, but I'm just wondering, is there any advantage to this over a basic lamp dimmer (under $10), or is it just a nicer appearance?

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No there isn't. This is just something you can put together yourself if you have parts lying around. You don't have to go with a metal box. There are plastic ones that are cheaper. I just think the metal looks cool and they have always worked for me. :sweeet:

Quote:

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Originally Posted by Raven01

Curious why you would use a 2 prong cord to run to a 3 prong receptacle?

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Thats what they had at walmart. The neutral acts as ground but yes if you have the 3 prong wires they are better. Just what I could find. Thanks :)

Quote:

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Originally Posted by led-zep

No there isn't. This is just something you can put together yourself if you have parts lying around. You don't have to go with a metal box. There are plastic ones that are cheaper. I just think the metal looks cool and they have always worked for me. :sweeet:

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Ok, cool, it does look really nice with the metal box.

The 2 wire service cord I found at walmart is usually used for power tools that are double insulated (this box isn't). But this is what I found and it will work, is it the best probably not. But since on my house 99% of the outlets are missing the grounding wire (Not my handy work) the ground wire on this plug is useless anyway.

This is cool and all, but I really don't think the average person with little to no knowledge of proper wiring should even attempt this, and rather just buy one of these for half the price:

http://www.homedepot.com/p/Lutron-Cr...0#.UmxbdZGzfRo

Quote:

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Originally Posted by The Serpent Merchant

This is cool and all, but I really don't think the average person with little to no knowledge of proper wiring should even attempt this, and rather just buy one of these for half the price:

http://www.homedepot.com/p/Lutron-Cr...0#.UmxbdZGzfRo

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Aaron. With all do respect, if this was even remotely hard I couldn't do it. I'm not saying you need to be an electrician, but if you can change an outlet in your house you can do this.

Quote:

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Originally Posted by The Serpent Merchant

This is cool and all, but I really don't think the average person with little to no knowledge of proper wiring should even attempt this, and rather just buy one of these for half the price:

http://www.homedepot.com/p/Lutron-Cr...0#.UmxbdZGzfRo

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This was my thought as well, but I figure if someone is going to do it anyway, it's nice to have comprehensive guide rather than trying to wing it with limited knowledge. Maybe a disclaimer saying that it's for people with wiring experience?

Ok guys I get it. Not as practical as I had thought. I respect that. I'll go in and add a disclaimer. Thanks :sweeet:

Quote:

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Originally Posted by led-zep

Aaron. With all do respect, if this was even remotely hard I couldn't do it. I'm not saying you need to be an electrician, but if you can change an outlet in your house you can do this.

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I agree with you, but there are sometimes 13 year old kids on this site who might mess this up. My husband would have no problem doing this, he does change outlets and has some experience with wiring, so it could be helpful to him. I personally wouldn't attempt this myself, but I've always relied on him for this sort of thing, so I have zero experience.

Quote:

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Originally Posted by Shera

I agree with you, but there are sometimes 13 year old kids on this site who might mess this up. My husband would have no problem doing this, he does change outlets and has some experience with wiring, so it could be helpful to him. I personally wouldn't attempt this myself, but I've always relied on him for this sort of thing, so I have zero experience.

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That's understandable. Thanks :D

You can plug one of this into a thermostat and use it as an emergency backup in case your thermostat fails open...if you're using it with one of the on/off thermostats that has a lot of bounce in the temp range, you can take a lot of that +/- bounce out of it also.

Quote:

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Originally Posted by led-zep

Ok guys I get it. Not as practical as I had thought. I respect that. I'll go in and add a disclaimer. Thanks :sweeet:

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It does have a practical application. For those that cannot afford proportional control thermostats could use this in conjunction with a cheaper thermostat. Running let's say IR bulbs of 150W @ 1/3 or even 2/3 rather than a 50W or 100 at full power on a cheap thermostat does two things.
First the bulb lasts much longer and secondly, it reduces the amount the temp can spike if the thermostat fails.
Some tweaking would be required to get it set right and personally I would prefer a dimmer that could be "locked" in at whatever you finally set it at after tweaking to help prevent mishaps.

Using a Metal box with no ground is not the best choice and taking the ground from the dimmer to the plug is not really doing anything, kind of pointless really. I would definitely use a 3 wire cord in this application and ground the metal box.

Also trimming the heat sink off the dimmer will reduce the wattage that the dimmer can handle so make sure it will still handle the load you intend to put on it.

Quote:

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Originally Posted by jason79

Using a Metal box with no ground is not the best choice and taking the ground from the dimmer to the plug is not really doing anything, kind of pointless really. I would definitely use a 3 wire cord in this application and ground the metal box.

Also trimming the heat sink off the dimmer will reduce the wattage that the dimmer can handle so make sure it will still handle the load you intend to put on it.

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You are absolutely correct. Taking the ground from the dimmer to the outlet is kinda pointless but it was there so I tied it in. Truth is I would use the 3 wire cord to ground the metal box but as I stated before none of my outlets in my house are grounded to the ground bus on the panel ( I didn't build this house ) so that's pointless too. If done properly this way will work fine though, is it the best way NO but it does work. O well if the admins feel this is more of a risk they can delete it I won't have any hard feelings. I was just showing a way I do mine that has worked for a good while. Back in the old days when my house was built a lot of times workers would take a pigtail and jump from the neutral to the ground on outlets, Its not the right way but its what they did a lot of times. For the record I am not saying do this. DO NOT DO THIS! Thanks

Quote:

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Originally Posted by led-zep

You are absolutely correct. Taking the ground from the dimmer to the outlet is kinda pointless but it was there so I tied it in. Truth is I would use the 3 wire cord to ground the metal box but as I stated before none of my outlets in my house are grounded to the ground bus on the panel ( I didn't build this house ) so that's pointless too. If done properly this way will work fine though, is it the best way NO but it does work. O well if the admins feel this is more of a risk they can delete it I won't have any hard feelings. I was just showing a way I do mine that has worked for a good while. Back in the old days when my house was built a lot of times workers would take a pigtail and jump from the neutral to the ground on outlets, Its not the right way but its what they did a lot of times. For the record I am not saying do this. DO NOT DO THIS! Thanks

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I was not trying to be hard on you but you have to remember a lot of the people that read this have very little to no knowledge of electricity and if the see an electrician post that this is a good way they might try it. If you are going to build this set up and go with an underground 2 wire cord I recommend you use a plastic box so It is not possible to energize the box accidental. the plastic box is cheaper also.

I'm glad to see another electrician in Texas in to reptiles though.

Quote:

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Originally Posted by jason79

I was not trying to be hard on you but you have to remember a lot of the people that read this have very little to no knowledge of electricity and if the see an electrician post that this is a good way they might try it. If you are going to build this set up and go with an underground 2 wire cord I recommend you use a plastic box so It is not possible to energize the box accidental. the plastic box is cheaper also.

I'm glad to see another electrician in Texas in to reptiles though.

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NO WORRIES! No hard feelings, you are right plastic would be better. For the record the metal boxes did concern me when first building these. Thats why I tried to stress the outlets with squeeze type terminals versus wrap arounds. To keep stray wires to a bare minimum. Also why I taped the hell outa it.

Quote:

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Originally Posted by The Serpent Merchant

This is cool and all, but I really don't think the average person with little to no knowledge of proper wiring should even attempt this, and rather just buy one of these for half the price:

http://www.homedepot.com/p/Lutron-Cr...0#.UmxbdZGzfRo

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Note those lamp dimmers don't take grounded plugs so you'll also need an adapter for many applications: http://www.homedepot.com/p/Leviton-1...9#.UmyAsH7D_4g

After positive feedback I would like to add on to this DIY. After finding an old 3 wire computer wire in my junk drawer I rewired the dimmer for 3 prong use. Please see updated pics. This would be the safer method to go with. Again always put plenty of tape around the outlet to minimize wire exposure.

http://i1022.photobucket.com/albums/...ps4e686852.jpg

http://i1022.photobucket.com/albums/...ps120e0256.jpg

http://i1022.photobucket.com/albums/...pse69f791a.jpg

http://i1022.photobucket.com/albums/...psd0034cd8.jpg

Quote:

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Originally Posted by bcr229

Note those lamp dimmers don't take grounded plugs so you'll also need an adapter for many applications: http://www.homedepot.com/p/Leviton-1...9#.UmyAsH7D_4g

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Very few heat sources used in the hobby have grounded plugs, but yes one of those adapters might be necessary.