Using Insta-charging

[josan6]

Some days ago I had a problem trying to charge a big refrigeration system with R-22, charging process was very low.
I asked to a friend about a "trick" to do this process faster, and he recommend me use a small device called Insta-charging, in this way, accord with him, I can charge refrigerant as liquid (drum turned down) directly on the suction line without dangerous for compressor.
Somebody has used?, is reliable?, somebody know another "trick"?.
Thanks everybody.

[NormChris]

The device is basically a chamber with fittings that attaches to your charging hose and which contains a restrictor that allows you to charge liquid but meters it at a rate that the compressor can take without slugging.

You can do the same thing yourself by regulating the flow of liquid through your manifold using your manifold valve.

[boat racer]

Systems with receivers can be charged from empty into the receiver and condenser very quickly by liquid charging into the receiver king valve without the machine running. The total system charge should be around 80-90% of the receiver capacity. If you have a 15 pound capacity receiver 12 pounds should be enough; 30 pounder ~25 pounds of refrigerant. To avoid over charging I never liquid charge this way from a vacuum; I break the vacuum to 0-20 psi with refrigerant gas and then liquid charge. Doing this you are putting liquid into the system where liquid normally is, so there is no danger. Always err on the safe side if you are not sure; it's easier to put more in than recover.

If the system is very large (hundreds of pounds) you can close the receiver king valve or condenser liquid valve and charge 100% liquid into the liquid line feeding the TXV if you have a liquid line service or access valve closer to the TXV. Do this with the machine running; you may need to jump the low pressure switch. You need to have some idea of how much refrigerant the system holds to do this.

Another trick for speeding up transfer from refrigerant cylinders is to pump gas out of the cylinder into the system with your recovery machine while the system is running. You can do this with cylinders that are mostly empty and/or cold that would otherwise be very slow chargers.

[R12rules]

It all depends upon the system you are charging.

I had a rack system, hundred of pounds of R-22, it was low on gas.
Fixed the leak then went down to one of the cases on the sales floor and gained access to the suction line near the TXV.

I removed the scrader valve core, using the tool made by C&D.
I attached my hose, which has the valve core depressor REMOVED from it, (all of my hoses are this way), and since the compressor was way far away .... like ... UP-Stairs in the motor room ....and there was lots of suction line before the compressor ... I dumped liquid right into the system.
Bottle after bottle after bottle.

This is but one method.

Another method for that same scenario is to lug up the cylinders into the motor room and attach your charging hose to the suction manifold.
Then let er rip. That works pretty godd also.


But if your system in question is less than ten pounds of charge, simply allow the vapor to enter the hoses and charge vapor only.

Anything larger than ten pounds, my method is to watch the suction pressure as the system is running. Then I begin adding liquid refrigerant into the system thru the low side. But I do not allow the suction needle to raise above where the running backpressure is at.

In other words, if the suction pressure while operating is at 25#, I will allow liquid into the system raisig the back pressure to 35#, but no more!

Frankly, this is how I charge most anything, even some smaller systems.
But I'm cautious of two factors.
1) You dont want to chill the compressor and wash out the lubrication!

2) You dont want to slug the comressor by attempting to forse liquid thru the valves!


Remember, compressor only pump vapor. Vapor only and NOT liquid!
Cold vapor never hurt a compressor. But liquid kills faster than you can say "ozone"



That "tool", that "charging aid" ...... it's been around longe than I have.
But if you watch what your doing ... you wont have any use for it.
Just pay attention to what is pumping inside your unit. And your systems will be alright!