Electrition/electrical help needed

[GamesterX]

I want to install a temp controller in my fridge to lager beers in it and as always I'm looking for cheaper alternatives then buying from the brew stores, I found two on ebay but not sure which to get, one is a 110v 5A other is 220v 10A,I can run the 220v but it would have to be unplugged 20min every other day for my wife to use her tanning bed and I don't trust her to plug it back in when done.

Heres the question,my beer fridge says its 6.5A "amps",the the 110 regulator says its 5A max and the 220v is a 10A max, is the 6.5 on my fridge constant or initial current? will the 110v work or should I go with the 220?

http://cgi.ebay.com/ws/eBayISAPI.dll...=p5197.c0.m619

http://cgi.ebay.com/Mini-Aquarium-Di...65002716234369

[LeftyMPfrmDE]

Take a look at the name plate of the fridge its useally on the compressor or motor in the back or bottom of the fridge. it'll tell ya the voltage of the unit (either 120 or 240 volts), unless its a fridge from a commerical kitchen, more then likely its a 120v. as far as the 6.5 amps, that vaule should be on the name plate under the "F.L.A.", or full load current. that's your running amperage draw of the fridge. start up current is useally 4-5% higher then then FLA, but thats only for a spilt second when the compressor kicks on.

that being said, if your fridge is 120 volts, with a 6.5 amp FLA, and get the 120 v control unit, it'll work for a little bit, but, over time, i think the amp draw from the fridge with fry the control unit, or you'll have fuses blow left and right in the control unit. (assuming it has interal fuses.)

now, if your fridge is 220v, you should just be able to wire the 220 control unit by intercepting the power cord of the fridge, and wire it between the fridge and wall outlet. but, you can't make the 220v controller work with a 120v source


you can always look around in the 'net for a johnson contols refrigerator thermostat, either digital or analog, for 120v refrigerators. they work great.. i got an analog, and hasn't let me down in two years. they are just plug and play; plug the thermostat in the wall, and then plug your refrigerator into the thermostat. done and done.

digital- http://cgi.ebay.com/Freezer-Fridge-T...item1e59e35491

analog- http://cgi.ebay.com/JOHNSON-CONTROLS...item45edeaabc8

Im all for DIY and modifying equiment for the brewhouse, but the last thing i want to do is incorperate my day job with my hobby

[NoonInGodinTepe]

I agree with Lefty. It'd fry at some point. On most 120 volt motors, which may apply to compessor motors, the amp reading is the "start" amperage. This amp draw is short, but deadly to under-rated contacts. Depending on the data plate, you may find it easier to properly size your t-stat by using a HP rating.

[Taz]

I agree with Lefty. It'd fry at some point. On most 120 volt motors, which may apply to compessor motors, the amp reading is the "start" amperage. This amp draw is short, but deadly to under-rated contacts. Depending on the data plate, you may find it easier to properly size your t-stat by using a HP rating.

You could use a Digital Thermo Controller with a SSR output. SSR's are cheap and can be sourced from china via ebay in 25 amp or 40 amp units The controller below is like the ones I use very reliable and well made and sell for around 20 bucks. You would need to mount the controller and the SSR with it's associated wiring in a PVC box.
Note that the DC input 3-30V can be sourced from a redundant mobile phone charger and there has to be thousands of them around. Just cut the phone plug off and wire it into the SSR making sure the DC polarity is correct. Either way round with the AC connections

http://www.homebrewchatter.com/board...attach/jpg.gif
http://www.homebrewchatter.com/board...attach/jpg.gif SSR around 5 bucks P&P included

[Lamppa]

I am not being rude here, just informative. Taz you need to slow that down a bit. I have a pretty good grasp on how ac systems work, due to my years diagnosing 12v dc automotive issues. that said, Im confused iwth what your saying and I think I speak for others as well.


you are saying to use a relay on the controler to limit the load on the controler from the compressor. is that correct?

[Taz]

I am not being rude here, just informative. Taz you need to slow that down a bit. I have a pretty good grasp on how ac systems work, due to my years diagnosing 12v dc automotive issues. that said, Im confused iwth what your saying and I think I speak for others as well.
you are saying to use a relay on the controler to limit the load on the controler from the compressor. is that correct?

No I am saying you are using a controller with a relay that can't handle the current.
What I proposed is a controller using an external relay that is well equipped to handle the current and voltage range 120-240V up to 25 amps that GamesterX is looking for to suit his problem without getting involved in split voltages with different appliances.
There is no limiting function implied with what I proposed just an easy approach to the problem. If GamesterX needs a wiring diagram I will draw one up and post it here to clarify the situation. The temperature controller I have shown has no internal relay but is designed to drive a SSR it has a PID function incorporating a wide temperature range.

[NoonInGodinTepe]

I know it got it covered Taz, but an explanation for some --

Instead of the thermostat supplying power directly to the compressor, where all the power for the motor runs through the t-stat (unheard of in commercial equip), the t-stat only powers a coil on a relay that suppies the motor voltage. And a SSR type of relay would be best as Taz said.

And you might check the unit out, it stands a good chance of having a relay on the side of the compessor.

[Lamppa]

I understand all that, I must have missed the original question or sometghing.

[Taz]

I know it got it covered Taz, but an explanation for some --

Instead of the thermostat supplying power directly to the compressor, where all the power for the motor runs through the t-stat (unheard of in commercial equip), the t-stat only powers a coil on a relay that suppies the motor voltage. And a SSR type of relay would be best as Taz said.

And you might check the unit out, it stands a good chance of having a relay on the side of the compessor.

Bear in mind the inrush of current to the motor under load will be well in excess of the running current. I am not familiar with your dual voltage setup over there but this may be compensated by a cap start. We have two phase and three phase setup here, two phase residential usually separates appliances like heat pumps and hot water systems as they are on a cheaper supply rate while the other phase is for power and light which are individually metered. Three phase of course is 415V usually for industrial application.