226W TEC on a Thermaltake Purepower 420 PSU?

[Gregz]

Can I run this 226W TEC on a Thermaltake Purepower 420 PSU ?

From the TEC spec sheet:

Power Supply Requirements

* Auxiliary power supply :
o The TEC module is provided with "bare wires" to facilitate installation with screw type terminals.
o We recommend the "Meanwell S320-12" power supply, rated for 25A at 12 Volts.

* While it is possible to connect the MCW5002 to the computer power-supply, users should be aware that only high-end power-supplies can accommodate the Peltier module 18amps current draw (at 12 volts). Accordingly, users should verify that their power supply features at least a 40 Amps ratings for the +12 volts rail.

I don't understand how the same TEC requires 25A, 18A, and 40A all in the same paragraph.

Do they recommend the 25A PSU because of inefficiency? The spec sheet for the Thermaltake PSU claims 18A at 12V, is that going to be sufficient assuming the TEC is the only load?

PSU
Specifications:
# 3.3v - 30A
# 5.0v - 40A
# 12.0v - 18A

I'm very much hoping I can use this PSU because it's the only spare I have laying around. Naturally I'd prefer to save a buck and use what I have. Can I get away with that here, or do I need to buy the PSU they recommend?

-Greg

 

[Premmer]

Can I run this 226W TEC on a Thermaltake Purepower 420 PSU ?

From the TEC spec sheet:



I don't understand how the same TEC requires 25A, 18A, and 40A all in the same paragraph.

Do they recommend the 25A PSU because of inefficiency? The spec sheet for the Thermaltake PSU claims 18A at 12V, is that going to be sufficient assuming the TEC is the only load?



I'm very much hoping I can use this PSU because it's the only spare I have laying around. Naturally I'd prefer to save a buck and use what I have. Can I get away with that here, or do I need to buy the PSU they recommend?

-Greg

Greg:

The chart below notes various operating voltages and corresponding current draws for a 226W peltier. The wattage column is the peltier’s cooling power, not to be confused with the peltier’s power consumption. Power consumption at the various voltages listed is simply the product of the desired operating voltage and the corresponding current listed; i.e. at 12V the power consumption is 12V* 18.94A or 227.28W. That means your 226W cooling power peltier is operating at ~ 62% (140.9/226) of its maximum cooling rating. If in your situation you wanted/needed additional cooling power and you are using a fixed output 12V PC power supply, you’re SOL.

If however you were to purchase the Mean Well Model S-350-13.5 Power Supply, you have the option to increase or decrease the supply output voltage by as much as 10% of the rated nominal output, 12.15V to 14.85V. The nominal output of this supply is 13.5V, 0 to 25.8A. This power supply is a better selection than the S-320-12. The downside is that is will take ~ 8 weeks for delivery from Component Distributors, Inc. http://www.cdiweb.com/PortalManufacturerDetail.aspx?ManfNo=332
You will have to get a price quote from them but my guess is that its cost will be ~ the same as the S-320-12 purchased from Sidewinder or Crazy PC, $86 - $95.

Specs for the 350 Series:http://www.meanwellusa.com/DataWebForm1.aspx

226 watt / 15.2 VMax / 24 IMax
5 volts: 24.5 watts; 7.89 amps
6 volts: 35.2 watts; 9.47 amps
7 volts: 47.9 watts; 11.05 amps
8 volts: 62.6 watts; 12.63 amps
9 volts: 79.2 watts; 14.21 amps
10 volts: 97.8 watts; 15.78 amps
11 volts: 118.4 watts; 17.36 amps
12 volts: 140.9 watts; 18.94 amps
13 volts: 165.3 watts; 20.52 amps
14 volts: 191.7 watts; 22.10 amps
15 volts: 220.1 watts; 23.68 amps

So let’s work through the confusing 18A, 25A and 40A ratings. The 18A @ 12V should be obvious from the chart above, not exact on the current draw but close enough for non-government work. If your supply is capable of delivering 12V @ 18A, it will work. The 25A must be a typo which relates to the peltier’s maximum current draw. Swiftech's website has 15.2V/24A which agrees with the table above. If you were to operate the peltier at its maximum ratings then you would need a supply capable of delivering 15.2V @ 24A. As for the 40A on the 12V line statement, I believe that would be a minimum current rating required if you were using your PC supply to power both the PC and the peltier. This is not the case for you as I understand it so its irrelevant.

Hope this helps a little. Good luck on your new TEC adventure.

 

[Gregz]

Premmer,

Thanks so much for the detailed reply.

If your supply is capable of delivering 12V @ 18A, it will work.

I've been told it's bad practice to run a PSU at its maximum amperage rating over a long period of time. How can I test the Thermaltake's resilience to long-term usage of 18A on the 12V rail? Is the 18A number a theoretical maximum for the PSU, i.e. should I expect the PSU to operate below 18amps?

Again I'm mostly trying to avoid buying another PSU as I'm already overbudget. How can I test to see if the Thermaltake 420 can indeed maintain 18A at 12V continuously for say...2-3 years?

 

[Premmer]

Premmer,

Thanks so much for the detailed reply.

I've been told it's bad practice to run a PSU at its maximum amperage rating over a long period of time. How can I test the Thermaltake's resilience to long-term usage of 18A on the 12V rail? Is the 18A number a theoretical maximum for the PSU, i.e. should I expect the PSU to operate below 18amps?

Again I'm mostly trying to avoid buying another PSU as I'm already overbudget. How can I test to see if the Thermaltake 420 can indeed maintain 18A at 12V continuously for say...2-3 years?

Thermaltake has published that the supply will deliver 18A on the 12V line. I have no reason to believe this is a theoretical rating and I would not be concerned about operating the supply at this rating for a long period of time as long as the ambient operating temperature is ~ 25C or less.

Also, do you realize that a minimum load must be present on the +3.3v and +5V lines to maintain supply functionally? You will have to calculate, purchase and install a dummy load resistor on each of these lines.

Just curious, what processor, speed and Vcore do you plan to operate at? I don't want to discourage you from using a TEC, but after reading dozens of threads on the subject, results are not that good.

 

[speed bump]

The 12v line on these PSUs is adjustable just undervolt it a bit and you should be fine since the amperage stays the same voltage goes down.

 

[Gregz]

Also, do you realize that a minimum load must be present on the +3.3v and +5V lines to maintain supply functionally? You will have to calculate, purchase and install a dummy load resistor on each of these lines.

I've never heard of that, now I know thanks.

Just curious, what processor, speed and Vcore do you plan to operate at?

AMD 3700+ San Diego, hopefully OC to around 3.0ghz @ < 1.65V.

I don't want to discourage you from using a TEC, but after reading dozens of threads on the subject, results are not that good.

Factual information is always good information, no need to apologize. In truth I'm beginning to think using a TEC isn't for me either. I did a calculation last night and learned I'd be spending an extra $250 a year on electricity just powering the TEC and water pump!

Power costs weren't something I had considerred until now, and they are very high...in my case prohibitively so.

I'll probably end up using a Thermaltake CL-P0114 Heatsink with a 2,800RPM 120mm fan. This should be comparible to a mid-grade water kit. The $400 I'll be saving(as well as the $250 annual from power) can be used to buy a faster processor.

 

[Premmer]

I've never heard of that, now I know thanks.



AMD 3700+ San Diego, hopefully OC to around 3.0ghz @ < 1.65V.



Factual information is always good information, no need to apologize. In truth I'm beginning to think using a TEC isn't for me either. I did a calculation last night and learned I'd be spending an extra $600 a year on electricity just powering the TEC and water pump!

Power costs weren't something I had considerred until now, and they are very high...in my case prohibitively so.

I'll probably end up using a Thermaltake CL-P0114 Heatsink with a 2,800RPM 120mm fan. This should be comparible to a mid-grade water kit. The $400 I'll be saving(as well as the $600 annual from power) can be used to buy a faster processor.

I think you've make a wise decision. I believe a high performance water-cooled setup, vs. a TEC setup, offers the best overclocking results for dollars spent.