EBay fish tank controller build using Wal-mart parts

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Misplaced_Canuck

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When I first saw/read about those eBay aquarium controllers, I thought they were great and I immediately bought 5. I built my first one out of a gray junction box (the sealed type) and it took me a good 2.5 hours to build one. I built a second one out of a 2-gang electric box, but it's a bit hokey (no fit and finish).

So yesterday I was at Wally World and decided to get a few parts to build my 3rd one. The first thing that came to mind was that those "square" electrical face plates look darn close to the size of the controller. May be it would work... So I got the parts to make it happen.

The build time was about 1h20m, including fetching tools, taking pictures, answering text's, answering calls, and flipping through TV channels. :D

Parts needed

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1x 2-gang electric box
1x 10-ft 13A electrical cord (some folks have used spare computer power cords)
1x square electrical outlet
1x square 2-gang electric box face plate
1x pack of wire nuts (only 2 are needed).

Total cost was around $15, the electrical cord being the most expensive part ($8 I think - Darn copper prices!)

Tools required

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Continuity tester (volt-meter) (optional, really)
Wire strippers
Razor blade cutter
Small flat screwdrivers (for the controller's posts)
Pliers
Small Phillips screwdriver
Dremel tool with de-burring drum attachment (not pictured).

Fitting the controller to the faceplate

The face plate looks like it would hold a controller nicely...I verified to see that the controller would fit in the face plate.

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And... It doesn't. It's actually a touch wider (may be 1/8"?) than the hole. Bummer. No despair, I took it outside (I didn't want plastic dust in the kitchen) and gently enlarged it with the Dremel tool. The de-burring drum really doesn't sand it down, it really melts the plastic from friction/heat. I did a little bit at a time, until the controller fit snugly (but not tightly).

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After the work with the Dremel tool, I mounted the controller into the faceplate, and latched the holding clips snugly to lock the controller in place.

Fitting the controller into the 2-gang electrical box.

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The gang box has a number of spots that can be made into openings for running wires. They also protrude INSIDE the box and this prevents the controller from fitting properly inside it. I punched out the top-right hole, and the 2 on one level lower (from the inside out).

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Then I used the Dremel tool to grind away any protrusions from the holes that I opened up. The idea is to make the bottom as flat as possible where the controller will go. It really didn't take that much time, may be 5-10 minutes. Just go slow and remove a little bit at a time and do not "punch thru" the back of the box.
 
Wiring

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I wrote a crude schematics on a post-it note (the next best thing would be a paper napkin of course). I wrote Black, Red and Green thinking it the cord had a red wire, but it was in fact white. (I'm no electrical engineer).

I counted the number of wires I would need, and figured out I needed a total of 8 wires. I figured that I'd need about 4" per wire for the connections.

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I cut the end of the extension cord, leaving a few inches on the head in case I wanted to use it to build a 3-way dongle.

I checked that the green wire is the ground by checking the continuity of the ground leg on the cord to each of the wires. Green = ground, check.

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I cut an extra 12" of the cord to get the 8 wires I need for the connection, and cut that piece into 4" pieces.

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I removed the outside insulation on the last 4" of the main cord, and removed all of the outside insulation on the 3x 4" pieces.

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I stripped and tightened the ends of each 4" wire to be used. I left about 1/4" for the ends that go into the controller, 1/2" for the ends that get wire-nut'ted, and about 3/4" for the ends that go on the outlet posts.

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I ran the main cord through the bottom opening of the box (a new one I punched out), and made a simple loop to prevent the cord from being yanked out the back.
 
Assembly

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In the above picture I screwed in the ground (green) wire of the main cord to the ground leg of the outlet. I've also attached one 4" wire to the "left" leg of the outlet.

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I'm continuing the wiring job by attaching the 1/4" ends of the 4" wires to the controller. I tightened each one snugly into the controller but did not overtighten.

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I intentionally broke the "right" side connector between the upper and lower portions of the outlet, so that one will operate for hot, and the other for cold.

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That's the final wiring.

Putting it all together

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I've wired the 2 wires for the sensor, and routed them through the same hole as the main cord. I also made a loop around the main cord to prevent it from being yanked out.

Here, I've screwed down the electrical outlet to the box, but not tight to leave a little bit of wiggle room.

I then gently tucked the wires behind the electrical outlet, and put the controller and faceplate on top of the box to try it out.

I adjusted the outlet, tightened it down, and put the faceplate on top of the box, and used 2 of the screws to hold down the face plate. Since the faceplate screws into the inserts (and NOT the box), there's nothing for the top screws to go into, so I just left them out. For looks, you could glue the remaining 2 screws into the outlet, but I'm all about functionality over looks.

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That's the final product. Looks decent, works great.

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The back of the box can be left as is, as there are no wires that show metal.

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Or, you can put electrical tape to cover the holes.... Or whatever other material you so choose.

M_C
 
:tank:
awsum cheap build im a contractor and i never thought about using 2 gang box i got a good 20 laying around. Totally stealing this idea..thanks

:ban:
 
That's nice. I used a open end junction box, cut a hole in the side, and screwed the "open" part into the wood countertop it's mounted under....doesn't look NEARLY as nice , or as neat, as yours. Well done.
 
Perfect timing, I literally just got my controller out of the mailbox about an hour ago. This is a great build and less bulky than the Radio Shack box build. I'll pick up the gang box and front plate tomorrow after work, thanks for taking the time to post this. :mug:
 
I have a large chest freezer I am usingas a ferm. Chamber, with a Johnson control temp probe power control. Say it gets too cold in the winter toferm in my garage, what could I plug into the"hot" outlet?
 
I have a large chest freezer I am usingas a ferm. Chamber, with a Johnson control temp probe power control. Say it gets too cold in the winter toferm in my garage, what could I plug into the"hot" outlet?

Anything up to 10A running load... A 100W light bulb or two, or a small space heater (10A or under)...

M_C
 
Anything up to 10A running load... A 100W light bulb or two, or a small space heater (10A or under)...

M_C

I've heard of folks using heating pads too, (like the kind you use for a sore neck...). Also, since light can be a ***** to beer, (although incandescents put out rather little UV, and CFLs are useless for heating), many folks prefer ceramic aquarium heater bulbs, (screw into any normal light bulb outlet), that only put out heat.
 
What about wiring it up as a replacement for my freezer's thermostat? I know I have seen a write up on this but can't find it now. HELP! PLEASE!
 
Good point on the UV from incandescent. I suppose a judiciously placed towel around the carboy would protect it from UV.

As far as the chest freezer bypass, personally I wouldn't do it. The freezer is already designed to go below the temperature of either of serving or fermentation. Just plug it into the temp controller, put the probe inside, and you're done. No messing with the freezer.

M_C
 
Misplaced_Canuck said:
Good point on the UV from incandescent. I suppose a judiciously placed towel around the carboy would protect it from UV.

As far as the chest freezer bypass, personally I wouldn't do it. The freezer is already designed to go below the temperature of either of serving or fermentation. Just plug it into the temp controller, put the probe inside, and you're done. No messing with the freezer.

M_C

I would,but the orginal themostat does not work. This is going to be my replacement themostat for a Ranger brand 6 cf chest freezer.
 
Cool... what is the OUTLET for? Does this whole thing go in the wall next to BOTH of ur units and then you plug the freezers into it?
 
If you used a 1k Watt or 1500 Watt element you could control the heat exchanger in a HERMS rig with this. What I'm wondering is if the temp probe that comes with this would take the 168 degree hot water during mashout? Obviously the probe is waterproof but I'm just wondering about direct contact with water that hot.
 
Cool... what is the OUTLET for? Does this whole thing go in the wall next to BOTH of ur units and then you plug the freezers into it?

Top of the outlet is for "heat" (aka you plug a source of heat to keep fermentation warm) and the other (bottom) is for cooling (you plug the fridge/freezer into it to cool down the fermentation).

M_C
 
I would,but the orginal themostat does not work. This is going to be my replacement themostat for a Ranger brand 6 cf chest freezer.

You need to find the wiring diagram, or try to figure it out yourself. You need to find the line and load wires going into/coming out of the original thermostat, and run those instead to the line/load, (the two contacts for cooling) on the ebay t-stat.

Wires should be pretty thick, coming out of the original T-stat. one should always be powered when the freezer is plugged in. The other should only go "live" when the compressor kicks on, (when the temp rises too much in the freezer). The line wire should be traceable back to where power comes into the freezer. The load wire should be traceable up to the compressor. Two other wires coming out of the compressor should be a ground and neutral, both traceable back to the power cord coming into the freezer again.
 
I was just at lowes last week looking for a box and decided on a 3 gang for for an always on outlet as well (for me a small fan, but a friend suggested a small radio for the yeast to jam too... sure).

I'm glad someone else test fitted this to make it work first while I still have the receipts! Thanks!

I've heard of folks using heating pads too, (like the kind you use for a sore neck...). Also, since light can be a ***** to beer, (although incandescents put out rather little UV, and CFLs are useless for heating), many folks prefer ceramic aquarium heater bulbs, (screw into any normal light bulb outlet), that only put out heat.

Not my idea, but what I did.

I substituted a 40W oven lightbulb and it worked for garage temps in the 20s, ferm temps in the 60s. Also, I wired the outlet to the lid so no light escapes the can.
 
Is it two stage; can you set both the heat and the cool parameters and have them both active all the time? I noticed the directions on eBay mentioned that the heat and cool indicator lights can't be on at the same time, but I don't know if that matters with your setup.

Thanks!
 
Is it two stage; can you set both the heat and the cool parameters and have them both active all the time? I noticed the directions on eBay mentioned that the heat and cool indicator lights can't be on at the same time, but I don't know if that matters with your setup.

Thanks!

It is two stage. You set a temperature and a swing (as low as 2*F) and it will take care of cooling and heating for you. The cooling and heating lights only are one when it's performing that function, hence the lights won't be on at the same time. So, if the temp gets too hot, the "cool" light turns on; gets too cold, the "heat" light will turn on. If it's the right temp (within the swing) neither will be on.

Also, you can set a "compressor delay" (0-10min IIRC) so your compressor doesn't pop on and off rapidly if the temps are unstable. You can also calibrate it.

If you go to ebay and type in "mini digital temperature controller" it will bring this up, for the folks who want links.

My only gripe is that it's in Celsius, so I have to have a little chart next to it. Definitely not a deal breaker for the price.
 
Yeah, I don't really know the advantage of the Ranco. Maybe they can get a 1*F swing or something. I don't know if 1 degree is worth an extra 100 bones though. Even for that reason, you could probably pick up a Love for around $50-60 with a 1 degree swing. My guess is that the Ranco is more ready to go out of the box. I have no experience with them, so I could be completely wrong.
 
great write up. I was looking on Ebay for these temp controllers. Question: do they only display in C and not F?
 
I ordered a couple. I can deal with Celsius, especially for the price.
Anybody know the life expectancy of the Love, Ranco, Johnson Controllers, STC-1000?
I have read where some of these fail after a few years. Might as well replace the $30 controller if I have to.

Question, we don't want too small of a temp swing right? We need to keep some swing to keep the compressor from constantly turning on and off. Don't want to wear the compressor out.
 
great write up. I was looking on Ebay for these temp controllers. Question: do they only display in C and not F?

There are sellers on e-bay that have an almost identical unit that reads in fahrenheit, but it's only single stage. I have one controlling my keezer and two in the control panel of my HERMS. If you want dual stage for a ferm chamber, they're all celcius.

Question, we don't want too small of a temp swing right? We need to keep some swing to keep the compressor from constantly turning on and off. Don't want to wear the compressor out.

Correct. It is highly reccomended to max out the compressor delay feature (10 min?), set the temp differential to at least a couple degrees F, and if possible secure the temp probe to something with some thermal mass so that it doesn't change drastically every time the door is opened. At least one of these things is a must to prevent short cycling the compressor and killing it. And FWIW you can actually set the STC-1000 to have a smaller temp differential than you can on the ranco controllers (0.3C < 1F), not that you'd want to.
 
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