Hi all .... I still do not understand how charging R407 in cooling system does indeed have to enter the liquid from the suction line?
Thanks ........
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Hi all .... I still do not understand how charging R407 in cooling system does indeed have to enter the liquid from the suction line?
Thanks ........
Yes, and the best place is before the accumulator.
The refrigerant must be drawn from the cylinder as a liquid.
Once it is removed from the cylinder, it's fine if it evaporates.
Some manufacturers make an orifice that fits into your charging hoses to flash the liquid off before it enters the system.
It is better to charge liquid R407 in liquid line (receiver), when compressor is stopped. When needed, refrigerant may be added in the liquid phase, carefully throttling the refrigerant on the low-pressure side and as far as possible from compressor. The compressor must be operating during this process.
hi Eep,
I take it you are charging from a vaced out system? so you have pressure tested . and veced out ? place your gas bottle on your weighing scales and charge the liquid into the recever< condencer< to the correct weight ,
if its a water chiller, or /and a water cooled unit all water pumps must be running. sedgy,
OK Thank's to all................
hi
you can charge it by throtteling way thats mean open and close
r407c can only be charged as a liquid and in a liquid port.if system has a refrig shortage then all the remaining gas must be recovered and be recharged with liquid only.
Sorry JimmyQuote:
Originally Posted by jimmy wilkes
What you are quoting is not std practise nowadays.
It has become quite acceptable to add fresh to what is a part charged system.
I know there is the argument about fictionalisation (splitting) of the refrigerant.
But experience has shown that total recovery and recharge with new is not always necessary or practical.
I would say it all depends upon the size of the plant.
There is nothing stopping a system being charged on the LP side.
Provided it leaves the cylinder as liquid and and enters the system as saturated vapour.
This can be achieved by throttling the valves across your manifold.
You do indeed need to be cautious about the amounts metered into the lp but it is a good way of finally trimming the system charge whilst running.
Although size of plant would again dictate.
Grizzly
The larger the system the less likely your added charge, which has the correct component proportions, is able to blanket the effect of any fractionation caused by a leak.Quote:
Originally Posted by Grizzly
Leaks toward the end of the evaporator and toward the beginning of the condenser will cause greatest degrees of charge fractionation.
I could not agree more.Quote:
Originally Posted by DTLarca
Where the leak occurs has great relevance as do many factors!
To be precise quoting the institute of refrigeration's
own service papers.
Zeotropic refrigerants can be added to a part charged system and it will work.
Except where a system is critically charged.
All i wanted to point out was that jimmy's statement was no longer entirely correct.
It is however one that a lot of people quote.
Grizzly.
I wasn't disagreeing with you - I was just expanding on a point I thought could be of interest to some if seen in more detail.Quote:
Originally Posted by Grizzly
Quote:
Originally Posted by DTLarca
Is there documentation available to support this?
I have a few systems with 407c in them and have already seen some major leaks (20-50% of the total charge)
Almost all leaks were at saturated vapor points in the system.
Is there a practical field test for fractionation?