I Has Fridge Compressor But No Skillz

[POLAND_SPUD]

yeah it is quiet... I think I remember your posts saying that 'damn I can't test ma farting machine cause it's 3 AM here and I don't want to wake my neighbours or sumthing like that.. so don't complain - that's an advantage

and yeah it gets just a little bit louder when it is under load... but it is still very quiet

[jackssmirkingrevenge]

no use having a quiet compressor if your launchers are loud tho

I have a nice 300 bar 3 litre nitrogen cylinder that would make a good accumulator, to what pressure can I expect to fill it and in what time interval?

[dewey-1]

JSR

You can wire it either way.

If it has markings of L or N or colors of Blue (N) and Brown (L) then you need to observe correct connection.

L=Line Hot Lead (Brown)
N=Neutral Lead (Blue)

[POLAND_SPUD]

Hmm about 3-4 minutes to fill it to 100 psi... you should be able to fill it to 500 psi in about 15-20 minutes

[MrCrowley]

Here are some pictures of my compressor:







So that means I have to connect 24v AC to the + and - which are coming from the diagram that connects to the battery and then connect the white cable to the 3 prongs on the compressor? Or is it the other way round? Not sure how I would go about wiring to the three prongs, seems a bit dangerous because it'd be open.

EDIT: Hahaha, turns out that on the side of the white plug is 3 holes which connect perfectly with the 3 prongs. So now i'm just wondering about the 24AC I need to connect to the controller. How many amps does it need to be?

[Technician1002]

Using AC will blow it up.

Use DC.

The white connector connects to the 3 pins on the compressor.

The DC is connected as shown in the photo below.
To turn it on, connect the two pins together marked TC which means Temperature Control.

The fan is for a DC fan in the fridge. You don't need to connect anything here.

Most compressors on that size will use up to 15 amps to start and will run at about 5 amps. Use a 15 amp fuse in the power line.

[MrCrowley]

Ahhh ok that makes sense. I guess 12v DC wont be enough? He was selling 12v ones as well, would've been easier for me to wire it up since I have a few 12v DC inverters or whatever laying around.

[Technician1002]

The 12 volts ones work the same, but use twice the current at 1/2 the voltage for the same power. Use a 30 amp fuse on the 12 volt model and it will run at about 10 amps.

[jackssmirkingrevenge]

MrC, are you driving yet? leav it dc and have an anonboard air supply

[MrCrowley]

Been driving the last three years, i'm not that young

Though you do raise a valid point, I'll have to have a think about how i'm going to set it up but that seems like a good idea.

[Technician1002]

Oh, Just a quick note on the DC Compressor, do not shut it off by disconnecting the power. This may improperly shut down the drive circuit and the inductance of the compressor may blow transistors. Always shut it off by using the Temperature Control contacts.

Using the proper switch point ensures the inverter is shut down safely without uncontrolled inductive kick killing the transistors.

I blew out an inverter once by disconnecting power while it was running a motor instead of shutting off the motor first.

[MrCrowley]

Just checked in the garage and I have nothing that comes close to converting 240v mains to 24v @ 15 amps. The only inverters I have for a car is to convert 12v to 240v, not the other way round and even so, 12v isn't enough for this compressor I guess. I did find a battery pack for a drill converted 240v to about 19.6v @ 3.3A but that was it.

Guess I'll go buy a proper power supply.

edit: one of your links says the 24v model needs a 7.5A fuse and requires only 2.5A while running. Seems like it can take up to 30v as well.


Edit 2: Could I use a computer power supply? I imagine they run at 12v though.

[Crna Legija]

my compressor gets quieter as the pressure rises.

[Technician1002]

edit: one of your links says the 24v model needs a 7.5A fuse and requires only 2.5A while running. Seems like it can take up to 30v as well.


Edit 2: Could I use a computer power supply? I imagine they run at 12v though.

Some computer supplies can put out enough on the + and - 12 volts to supply that, but many can't. Most computer supplies won't run properly without a proper load on the 5 volt supply.

Some mini fridges can use less power. I'm not sure of the capacity of the compressor you have. The current will vary with load.

The 30 volt max is so the compressor will run while the charging system is running. A 12 volt battery will often take up to 14.6 volts charging. On a 24 volt system, this can be as high as 19.2 volts. This simply means it won't fry while the engine in the RV or boat is running.

If you were not so far away, I have a stack of 30 volt adjustable 10 amp power supplies.

[jackssmirkingrevenge]

Been driving the last three years, i'm not that young

I know, I know, PUI

Though you do raise a valid point, I'll have to have a think about how i'm going to set it up but that seems like a good idea.

Stick in the boot with a fire extinguisher as an accumulator

I was rummaging through my parts box and remembered I have this compressor I had "obtained" from work, if it works it probably doesn't do more than 10 bar but could be cascaded, 500 psi isn't quite going to cut it when I'm used to 3000 psi tanks regged down to 800.

I could use it for a large bore pneumatic, but now that I've dipped my foot in hybrid lake, hmmm...