Cabinet Temperature Controller

[mangoat]

ive just done up a tempterature display that i will put behind clear perspex in the door of my enclosure so i can see the temp inside, shows me the temp without opening the enclosure, and well, if it is ok for the first couple of runs, means it should be the same for all, provided the weather doesnt change.

people would love central temperature reading data and stuff, but im not that smart.

my thing does for me, as everyone's own idea works for them.

id personally prefer to run fans from the get go, cause well, i am in australia, and its blimmin hot at christmas.

my 2 cents

cheers
goat

 

[multicast]

My method is to use a meanwell HRP power supply as these are very reliable but also have a fan on the end and air flows across the whole power supply.
I fit this into a smaller box where the power supply and controller fit snuggly and then fit vents on either side of the control box. This allows the air to be directly suicked from outside and then blown back out using the meanwell built in fan and control, this ensures that temps never get too high and im not relying on a secondary fan circuit to remove the heat. Ill need to add some pictures next time i build some more to show the design.

This is the ideal solution, and its what we did in our E16-ii controllers of which many thousands ran very happily. Just the fan that was in the power supply. The important thing is to ensure that the exhaust air doe'snt recirculate in the box. If you can achieve that, your all good. get creative with some ducting!

 

[plasmadrive]

I know I am a bit late to this thread but why not just use a Kliixon?

http://www.sensata.com/klixon/thermostat-precision-7bt2.htm

 

[Greg.Ca]

Wow, just came across this older thread and wanted to offer how I cooled my power supply cabinet for my pixels. I did it a very simpler way. Much simpler and VERY reliable.

I have a power supply box that has 12 SE350 5V Meanwell power supplies (see enclosed photo). This box obviously needed to be cooled when the pixels were running or when outside temperature caused the internal temperature to rise. I had to protect my power supplies as well as make sure that everything was working properly.

I selected a simple 'snap' switch which closes at a pre-determined temperature. I chose 20 degrees celcius which is approx. 70 degrees Fahrenheit here in the USA. When the switch determines that the internal temperature has risen over 20 degrees, then the switch closes and provides AC power to my AC fans. I have two 120VAC fans in the cabinet as well as two 'inlets' for providing input cooling.

Everything worked perfectly last year with the enclosure cooling. No issues what so ever, however I should mention that I built into the design a manual fan shutoff and a manual 'on' switch which is wired in parallel with the snap switch to test everything and to have the availability of by-passing the fan.

If you look just above the portable temp monitor, you will see the manual 'on' switch and just to the right of the switch you will see the snap switch. WAY easier and cheaper to cool your enclosure. Also MUCH more reliable. --Greg--

Firstly I didn't set out to make a cheap HoHoHo solution. I set out to use what I had available.
Bymetal strip have their place. sure. But I am lacking to see how using multiple metal interfaces conducting heat from the base plate is "better" than measuring the ambient air temperature.
I am also failing to see how turning them on at 20 degree C is "better" than just leaving them to run at full speed permanently. Where as my fan turn on slowly and ramp up as the temperature rises higher. On coolish days they stayed off or turned on for short periods only.

Finally Please explain HOW and mechanical Bimetal switch is MUCH more reliable than an electronic cct.

OK, it looks like I may have touched a nerve here. Not sure what to think bout that? I'm always open to different ideas to how someone else's solution to the same problem is different from my own. Isn't that the purpose of these forums?
Sorry you felt I designed a 'cheap HoHoHo solution'. I designed a solution a couple of years ago that was simple, reliable, easy and inexpensive. It keeps my power supplies operating between 15C and 20C. Exactly what I designed it to do.
It measures ambient air inside my power supply cabinet as the switch is free standing and isn't mounted or touching anything inside the cabinet. It senses AIR temperature. Look at the photo again.

In the city where I live, (Denver Colorado USA) we can in our Christmas season have day time temperatures from 20C down to -30C at night time. I don't want or need my electronics being cooled off when it's snowing and yes it certainly does snow in November-January. This is our winter season. It occosionaly does get hot enough at times in our winter season that this box absolutely needs two AC fans to cool off the 12 350 watt 5V power supplies. The snap switch reconizes this condition, closes and allows the AC fans to operate at full AC voltage until the internal cabinet temperature goes down to 15C. It simply works perfect. My design also included a manual switch in parallel with the temperature switch and also in series was a 'disconnect' switch should I ever need to force the fans off or force them on. A simple 'no brainer'. These have been in operation for years and has never failed. All of my subsequent power supplies for new pixel projects use this same design for cabinet cooling. I see no reason to change.

These bimetal switches have been used for decades by hundreds of manufactuers with no problems in all kinds of industrial and commercials environments. As far as how this is more reliable than a electronic circuit, I am only going back to the simplicity of the design and the lack of parts, components and connections. All of the connections are done on PLC din rail which is how all industrial applications are constructed. See photo. All of my pixel projects are done on PLC din rail.

Please see attached data on snap switches. Below are just a few sites that offer data on these snap switches. You can find them on ebay for just a couple of dollars including shipping.

http://www.ebay.com/itm/10pcs-KSD301-Temperature-N-O-NO-Controlled-Control-Switch-20-C-68-/121516647563?pt=LH_DefaultDomain_0&hash=item1c4af4e48b

http://www.sensata.com/klixon/thermostat-precision-m1.htm

http://thermodisc.com/en-US/Products/Bimetal/Documents/60T%20Product%20Bulletin.pdf

http://www.senasys.com/

--Greg--