Differential Thermostat

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Brianellul
Brianellul Solar Expert Posts: 95 ✭✭
Can anyone recommend a good differential thermostat similiar to the 'Kera tech DSD-2'? I've read in an article of Home Power about someone who used it in a Water Solar system but I can't find it on the net... their website is down!

Regards
Brian

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  • BB.
    BB. Super Moderators, Administrators Posts: 33,468 admin
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    Re: Differential Thermostat

    From an earlier thread here... One guy used this controller... And other link on the same thread, another guy decided to build and market his own DC powered differential controller.

    Don't know anything about the vendors or the controllers other than what I have read on their websites...

    -Bill

    Of course, from the Home Power article (PDF file), they listed Kera Tech's address:

    Kera Technology, Andy Lukas, 1320 Midway Blvd., Unit
    21, Mississauga, ON L5T 2K4, Canada • 905-566-0823
    Fax: 905-566-9036
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • sawmill
    sawmill Solar Expert Posts: 93 ✭✭✭
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    Re: Differential Thermostat

    I recently purchased a Steca 301 differential controller for a solar hot water system. I have been very satisfied with this unit and the many programmable options it provides. This unit is made in Germany and was reasonably priced.
  • Brianellul
    Brianellul Solar Expert Posts: 95 ✭✭
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    Re: Differential Thermostat

    This is proving to be a nightmare!!!! I found the Steca 301 differential controller specs really attractive BUT it seems that I'll be having a problem to have it shipped to Europe since all of the suppliers I found on the net don't even answer back my emails. Well I guess I have to keep on looking ;)

    Regards
    Brian
  • BB.
    BB. Super Moderators, Administrators Posts: 33,468 admin
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    Re: Differential Thermostat

    Steca is a German company--Try www.stecasolar.com and see if they can help you directly...

    By the way, I fixed my link to the GL-30 controller that was used in this project...

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Solar Guppy
    Solar Guppy Solar Expert Posts: 1,989 ✭✭✭
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    Re: Differential Thermostat

    I think a GL-30 would work just fine on 230/50hz. I have used the GL-30 and its a great contoller and very reasonably priced

    http://www.solar-components.com/gl30.pdf

    The differnce in 240vac/60hz and 230vac/50hz for this devices would not make any operational difference
  • BB.
    BB. Super Moderators, Administrators Posts: 33,468 admin
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    Re: Differential Thermostat

    This thread was about differential thermostats and turning on/off a pump to move hot water to a "cool" water storage tank for solar hot water.

    Your issue sounds like your thermostat is set for Celsius/Centigrade scale instead of Fahrenheit.
    • 20C = 68F
    It sounds like you just need to look up your thermostat's programming manual and find out how to switch between C and F.

    Today's electronic thermostats are pretty reliable. And you can get many that are very programmable (programmable temperatures during the day, and even ones that will randomly turn on the fan to filter your air).

    Define your needs then pick one that will fill them.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Cariboocoot
    Cariboocoot Banned Posts: 17,615 ✭✭✭
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    Re: Differential Thermostat

    I'd say you're right, Bill, except that 20 C is 68 F:

    degrees Celsius * 1.8 + 32 = degrees Fahrenheit

    (degrees Fahrenheit - 32) / 1.8 = degrees Celsius

    Try these formuli with 0C (32F), 100C (212F), and -40 (same in both systems). :D

    I grew up dealing with both, and still can't get away from having to do Metric/Imperial (and SAE) conversions! :p
  • BB.
    BB. Super Moderators, Administrators Posts: 33,468 admin
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    Re: Differential Thermostat

    Marc,

    I goofed. Was in a hurry and added 36 instead of 32.

    Bill:blush:
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset