Portable A/C modification help


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Old 06-19-20, 08:59 PM
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Portable A/C modification help

Weird situation here. Hoping someone can help.

Im trying to make a glycol chiller for beer making. I have a newish portable ac that I tore apart for the chilling component.

I need to bypass all the circuit board electronics. I want to send the electric from the plug, to the capacitor, to the condenser and fan.

is this possible? And if so, can anyone help me with the many different wires and relays?

I figure I donít need the relays. I want to use a temperature controller outlet to turn on and off based on glycol temp, but there are three relays. I just donít understand the wiring enough to do this.

any help would be greatly appreciated!!
 
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Old 06-22-20, 09:13 AM
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Connect the fan motor to the incoming power cable just like the compressor. That motor runs on 120v. The splash motor should no longer be needed but if it's 120v it can also be connected the same way as the fan motor.
 
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Old 06-22-20, 10:43 AM
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They will kink extremely easily.
Best to use tubing benders.
What temperature glycol are you trying to achieve?
 
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Old 06-23-20, 03:44 PM
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Don't forget to post some pictures of your brew rig and frermenters. This weekend I'm making a Chinook IPA.
 
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Old 06-20-20, 06:14 AM
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Boy, using a mini fridge or chest freezer is much easier.

If you want detailed help you'll at least have to tell us exactly what AC you have and post some good pictures of the control board and wiring. From that some of our experts might be able to figure it out.
 
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Old 06-20-20, 06:16 AM
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How exactly are you going to cool the glycol? You’d need to replace the evaporator with a liquid to liquid heat exchanger.
 
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Old 06-22-20, 07:24 AM
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Im going to very carefully bend the copper wires going to the evaporator, and pull the evaporator out of the air conditioning unit and put it in a cooler filled with glycol. This is a somewhat common way to build a DIY glycol chiller. A freezer would be easier, but the issue with the freezer is first off its big, second the compressors are tiny and take a long time to freeze the glycol. Plus, I already have a portable AC that I am not using that I want to dedicate to this project.
 
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Old 06-22-20, 07:43 AM
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Mostly figured out, except for condenser fan.... Any help would be apprecaited

OK, so I tore everything apart yesterday electronically. Basically this unit has an upper fan to blow the cold air through the evaporator and out of the unit, a lower fan which pulls hot air off of the condenser and send it out the back to be vented out of a window. It also has a small splash motor which I believe takes water that collects in the tray and throws it up against the condenser to cool and evaporate it.

I was able to bypass the circuit board for the compressor. Basically I pulled the hot and neutral wires from the plug off the board, I sent the hot wire right to the compressor and I sent the neutral wire to the capacitor, which ultimately feeds into the compressor. I just cut and spliced the wires. That works fine, the compressor now kicks off when electric is supplied by plugging in the unit, just as I want, because I want to control electric through a temperature controller that probes the temp of the gylcol.

Here is where I can use some help. The lower fan motor wiring diagram is not clear to me.

I will attach some pics to this thread. Basically the lower motor has two red wires that go into a capacitor, Im assuming this is for overflow protection. That part is fine and does not need to be touched. In addition to the two red wires, there is a higher gauge white and black wire that come off the circuit board and go into the motor along with the two red that connect to the capacitor. And of course the motor is grounded as well.

So what I need to figure out is the white and black wires coming off of the circuit board. My assumption is that is just hot and neutral, but what's not clear to me is if they are being run through a resistor or anything else on the board, or if I can just splice my hot and neutral and send that right to the fan motor? The fan motor has a wiring diagram which I will attach a pic of. It looks to me like its running through an inductor, which doesnt make sense to me, because I thought only DC needed an inductor. But that is why I need help.

So ultimately, if I can kick off the lower fan motor automatically, I think I am in business. The splash motor would be great too, but I think that is optional.

So, can anyone confirm if I can just splice my hot and neutral wires from the plug, and send those to the lower fan motor, or do I need to do something else?

Pic 1 is lower fan motor wiring diagaram
Pic 2 is black and white wires coming from circuit board that run to lower fan motor
Pic 3 is overall circuit diagram

Thanks for any help!!



 
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Old 06-22-20, 08:48 AM
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Hi, that wiring Dia. is hard to read, to fuzzy ,is sounds like you want all the fans and compressor to run at the same time, just curious how you intend to cool the glycol, are you planning on putting the AC evaporator in a tank of it?
Geo
 
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Old 06-22-20, 08:53 AM
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Yeah, the diagrams are really small, that was best I could do.

The upper fan does not need to run at all, once I pull the evaporator out, the upper fan has no use. So basically I want to run the compressor, and the lower fan that pulls heat from the condenser. And if possible the splash motor too.

I will gently bend the copper wires to pull the evaporator away and put the evaporator in the glycol tank.
 
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Old 06-22-20, 10:00 AM
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Thanks PJmax, much appreciated that is what I thought as well, but wanted to confirm with someone who understands this stuff better than I do. Ill give this a shot and if it works, I am in business, just have to carefully bend the copper wires to get the evaporator out without cracking the copper.
 
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Old 06-22-20, 10:13 AM
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Those aren’t wires. They are pipes. And refrigerant passes through them.
You can’t kink or break them at all. If they break it’s an instant refrigerant leak. If they kink the unit will not work.
 
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Old 06-22-20, 10:26 AM
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roughneck, yeah, I got it, I mistyped, but I definitely understand. breaking is very bad, kinking not good. I may use a heat gun on a low setting to warm up the pipes before I bend them, but I definitely understand the sensitivity of what I am doing. Anyone know how easy these things are to break?
 
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Old 06-22-20, 10:58 AM
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I will look into tube benders, thanks! I am trying to get the glycol down to around 15-20 degrees F.
 
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Old 06-22-20, 02:01 PM
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So I got all the wiring working, I have the condenser fan and the compressor kicking off as soon as electric is plugged in. Exactly as hoped, thanks for the help!

Still have to bend the copper tubing.

Question, Im assuming that by running this thing like this and taking away some of the thermistors I am hurting the life of the compressor and fan,is that accurate, or should this be OK? I think an AC can run for days straight with no breaks if needed right?
 
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Old 06-22-20, 03:48 PM
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That is one reason using a dorm fridge/freezer works much easier. They are designed to achieve the sub zero temperatures you are trying to achieve. Air conditioners are designed not to get that cold which would cause them to freeze up. Since you are tossing all the controls, all the protections are also removed so it's up to you. Worst case, it will run until it stops.

Are you keeping the fine/delicate aluminum fins or are you removing them?

I assume you are controlling your fermenter temperature by the flow of glycol. Are you also using a thermostat to turn off the compressor when your glycol reaches the set temperature?
 
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Old 06-23-20, 01:04 PM
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I plan to use a temperature controller with a probe in the glycol to turn the chiller off when it reaches around 15 degrees F and turn it back on when it goes over 22.
 
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Old 06-25-20, 10:36 AM
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Awesome! Im a big IPA guy, love them.

I will get some pics up when done, Im trying to go from small pots and pans and kits to a bigger setup, I'm in transition now.
 
 

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