Controlling temp in refrigerator conversion

[silversurfer513]

My set up is a door mounted refrigerator converson. The lowest temps I have seen are 40 to 41 degrees. What are my options for getting colder temps? I have seen the external temp controllers and my worry is that it would just cause the compressor to run ALL the time. Thanks in advance!

[NoodlesWIU]

The Brewer's Edge II would work well. Set your temp to as cold as it goes on your fridge, and you would set the Brewer's Edge II to your desired temperature. Then set the Differential say of +- 2 degrees. Then their is also an overload short cycle setting so to speak that says wait from 0-12 minutes before adding power again to the female plug.

IE if your set point is 36, with a 2 degree diff and a 10 min short cycle, and your unit starts at say 41, the unit will kick on giving juice to the female plug (which your fridge will be plugged into), and once it reaches 36 degrees it shuts off power to your fridge, so in essence power to the compressor is gone because their is no power to the fridge. now if the temp raises to 39 degrees it would normally turn on right away, but if you have the short cycle set to 10 minutes, and its only been 8 minutes since the temp reached 39 from that 36 set point where the Brewers Edge II shut off power to the fridge, it will wait 2 more minutes before turning back on.

So which ever is greater will be when it kicks on. If the temp is outside the range you set it will kick on, unless your short cycle time of say 10 minutes has not elapsed yet.

Oh the reason why you set your fridge to as cold as possible is you dont want that fridge to overide your Brewer's Edge II setting. An example would be if you have your fridge set to 41, and your brewers edge to 36 with a 2 degree diff. If the fridge is at 40, the Brewers Edge will give power to the unit because its outside its set range, but the fridge's internal thermostat says its 40 degrees, you set me in the fridge for 41 to maintain, im not turning on my compressor because im not supposed to go any colder than 41.

Hope this helps!

[silversurfer513]

The Brewer's Edge II would work well. Set your temp to as cold as it goes on your fridge, and you would set the Brewer's Edge II to your desired temperature. Then set the Differential say of +- 2 degrees. Then their is also an overload short cycle setting so to speak that says wait from 0-12 minutes before adding power again to the female plug.

IE if your set point is 36, with a 2 degree diff and a 10 min short cycle, and your unit starts at say 41, the unit will kick on giving juice to the female plug (which your fridge will be plugged into), and once it reaches 36 degrees it shuts off power to your fridge, so in essence power to the compressor is gone because their is no power to the fridge. now if the temp raises to 39 degrees it would normally turn on right away, but if you have the short cycle set to 10 minutes, and its only been 8 minutes since the temp reached 39 from that 36 set point where the Brewers Edge II shut off power to the fridge, it will wait 2 more minutes before turning back on.

So which ever is greater will be when it kicks on. If the temp is outside the range you set it will kick on, unless your short cycle time of say 10 minutes has not elapsed yet.

Oh the reason why you set your fridge to as cold as possible is you dont want that fridge to overide your Brewer's Edge II setting. An example would be if you have your fridge set to 41, and your brewers edge to 36 with a 2 degree diff. If the fridge is at 40, the Brewers Edge will give power to the unit because its outside its set range, but the fridge's internal thermostat says its 40 degrees, you set me in the fridge for 41 to maintain, im not turning on my compressor because im not supposed to go any colder than 41.

Hope this helps!

Good info, thanks. I guess Im still a bit perplexed on how this controller will override the fridge thermostat. If it is only controlling power to the compressor wont I still somehow have to bypass the fridges built-in thermostat?

[NoodlesWIU]

If you are plugging the power cord of your fridge into the female plug of the Brewer's Edge II, all the Brewer's Edge II is acting like a light switch, turning on, or off power to the whole Fridge.

So the internal thermostat of the fridge technically has the highest priority.

Here's an example.

Your fridges thermostat you set to 42 degree. And it acts normally that when the temperature goes above 42 degrees, the compressor kicks on until its cooled to 42 degrees. Simple enough, works the way any fridge should work.

However if you plug the fridges cord into the Brewers Edge, and your settings on the Brewers Edge are for say a 36 degree set point, the probe from the brewers edge will read inside the fridge that its 42 degrees, so give power to the fridge because its above the 36 degrees you set for it, so it flips that switch giving power to the Fridge.

But now your fridge says ok im on, but my temp is 42 degrees, and thats "MY" internal set point. I know nothing about this brewers edge, my thermostat says not to turn on the compressor until I go above that temp so I will stay at 42 degrees.

End result power will always be given to the Fridge by the brewers edge because it will never reach the 36 degrees because the fridges thermostat says dont cool past 42 degrees!

So by setting the fridge's thermostat to as low as it can go, say 28 degrees the brewers edge is free to control the unit because your not going to set your brewers edge below 28, unless you WANT frozen beer. *laughs*

Example: fridge thermostat set to 28, brewers edge set point to 36, internal temp of unit is 42 degrees. The Brewers edge gives power now to the Fridge because its above the set point. The fridge now has power and sees the internal temp as 42 and wants to get to 28, so it turns on the compressor trying to get down to 28 degrees. Once 36 degrees is reached, power is cut to the fridge from the brewers edge so of course the compressor cant run, and could never get to 28.

Does that help any?

[cubby_swans]

It's a good explanation, but I see in the 1st post by silversurfer that his fridge doesn't get any colder than 41 or 42. I would assume he's got it at the lowest setting. So, if that is the case, the brewers edge will only work if he re-wires his fridge to bypass it's own thermostat.

[silversurfer513]

It's a good explanation, but I see in the 1st post by silversurfer that his fridge doesn't get any colder than 41 or 42. I would assume he's got it at the lowest setting. So, if that is the case, the brewers edge will only work if he re-wires his fridge to bypass it's own thermostat.

Thanks cubby, that is correct. Im assuming there is way to bypass and wire the compressor directly but I have no idea how to go about doing that correctly.

[silversurfer513]

Ive been chewing on this all day and a few more thoughts come to mind. If my thermostat on the fridge is at the lowest setting (which it is) and the coldest temp Im seeing is 41 degrees, what is the final determining factor for that temp? Is the the thermostat set up to have 41 deg. as its lowest possible temp or have I reached the maximum cooling capacity of the refrigerator itself?

Im realizing that if the frigde itself is at its capacity to cool then an external temp contoller wont make a difference even if the internal thermostat is bypassed.

[jumper]

Unless your compressor is running non-stop your fridge isn't at its maximum capacity. It sounds like the thermostat is at its lowest level and/or there is a function limiting the compressor cycle to legnthen its service life.

The Brewmaster II would bypass all these controls and run the compressor to the set temp. It'll increase the duty cycle on the unit but you'll get your beer cold.

[cubby_swans]

Unless your compressor is running non-stop your fridge isn't at its maximum capacity. It sounds like the thermostat is at its lowest level and/or there is a function limiting the compressor cycle to legnthen its service life.

The Brewmaster II would bypass all these controls and run the compressor to the set temp. It'll increase the duty cycle on the unit but you'll get your beer cold.

NO NO NO The brewmaster will not bypass all these controls. The brewmaster is nothing more than an outlet and a temperature sensor. It doesn't control the compressor, it only supplies power to whatever is plugged into. The brewmaster will simply supply power to the refrigerator always because the refrigerator's controls will not allow it to get below 41. If the fridge can not get below 41 on it's own, and you set the brewmaster to, say 36, the brewmaster will always supply power to the fridge and the fridge will still never get below 41 because it's own thermostat will kick off the compressor. It would be no different than plugging the fridge into the wall.

The only way to bypass these controls is to rewire the refrigerator itself to bypass these controls so that the compressor always runs when the refrigerator is on.

[jumper]

I know what the unit is and how it hooks up. I'm assuming he's going to bypassing the stock thermostat. If it won't go down past 41 why would you leave it in the loop?

[cubby_swans]

I know what the unit is and how it hooks up. I'm assuming he's going to bypassing the stock thermostat. If it won't go down past 41 why would you leave it in the loop?

You wouldn't. But you said "The brewmaster II would bypass all these controls". A bit mis-leading (and contradictive to earlier posts) to someone who read that statement and doesn't necessarily know what the unit is and how it hooks up, because it doesn't bypass anything.

[KingPin461]

I know what the unit is and how it hooks up. I'm assuming he's going to bypassing the stock thermostat. If it won't go down past 41 why would you leave it in the loop?

You wouldn't. But you said "The brewmaster II would bypass all these controls". A bit mis-leading (and contradictive to earlier posts) to someone who read that statement and doesn't necessarily know what the unit is and how it hooks up, because it doesn't bypass anything.

Gentlemen.......Lets take the gloves off and just have a pint (or two)

[silversurfer513]

Update. I removed the upper shelf I had been using to store extra bottled beers and things have vastly improved! Measuring temps from a bottle of water at the bottom of the fridge at a consistent 37-38 degrees. Tapping a new 1/6 of Goose Island 312 Urban Wheat this afternoon. Cheers!

[BrewGuru]

Congrats!

So it sounds like you have an airflow problem, a small blower inside the unit to improve circulation might allow you to continue to store bottled beer and get proper dispense temp in your keg.

I prefer not to recommend the brewers edge or any unit that controls an appliances main power source for home-built kegerators, as they directly cause the evaporator fan to shut off, killing air circulation and impeding defrost of the evaporator in air defrosted models.

Imagine the ice buildup that occurs on electric defrost units! Esp. in certain environmental conditions, the controller turns the fridge on, it runs down to temp and the controller shuts it off off, now if the unit is electrically defrosted, the internal thermostat would open, and the elec defrost kicks on, to melt away the condensate on the evap, however, in the exterior controller scenario, when the external control cuts power, the condensate and ice is still built up on the evap coil, slightly melty (and not melting off quick at 30-40ish F, which exacerbates the problem), and still there the next time the control kicks on, which makes for a MASSIVE solid block of ICE at some point in the cycling future. If you're lucky, the compressor doesn't sieze, the ice doesn't put enough pressure on the evap to cause a refrigerant leak, then you either manually defrost, or WAIT a LONG TIME for it all to melt off and hope your refrigeration system works when you fire it up after the melt off...


Generally it is best to install a proper controller to control the compressor of a unit, wired in with any other necessary electrics, freezestat, elec defrost, etc... and leave circulation fans running all of the time.