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gwilliamson
14-05-2006, 07:26 PM
Hi chaps, sorry for asking such a blonde question.
But what is the correct format for charging or topping up 410a refrigerant. Most a/c units now (splits) only have connections on the gas side and 410a must be charged in liquid form!?. What the correct way of safely perming a regas or adding extra?

Peter_1
14-05-2006, 10:01 PM
Add liquid gentle in the suction. 3 seconds open,wait 20 seconds, open 3 secons , 20 seconds...
Listen also to the sound of the compressor.
Also, most compressors have a suction accumulator.

Argus
15-05-2006, 09:30 AM
.

The quick way to wreck any compressor is to charge liquid into the suction ? even small amounts can be hazardous for the compressor.
You cannot compress a liquid and damage will be the result.

In all probability it will settle in the accumulator, if you have one ? but there is a possibility of oil dilution in the sump and even liquid entering the compression chamber.

The reason for the liquid-only rule is that if you have a Zeotrope blend (i.e. a 400 series refrigerant) there is no guarantee that the vapour will be in the correct proportions in the cylinder, hence the rule about charging liquid. This is especially important with high-glide refrigerants, such as R 407C. The less liquid there is in the cylinder, the greater the likelihood of component separation and this in turn impacts on the composition of the remaining liquid ? it may not being of the right specification. It?s best to keep to full cylinders as far as possible. In reality, small variations in mixture composition in very small machines often have minimal effect on the performance and frequently go unnoticed, but it can be significant in large ones and lead to capacity loss.

R 410 A is a near Azeotrope, (it has a very small glide ?about half a degree - it can sometimes be ignored) and vapour charging is sometimes done, but be careful. The correct way is to charge liquid.

If you are working with a small split system, I note that many of them still do not have liquid line gauge connections, even though they work on 400 series blends. That is nothing less than manufacturers ignoring the obvious.

So, if you have a unit with 400 series refrigerant, and no liquid line port to charge with ? you have a problem.

.

.
________
buy silver surfer (http://vaporizer.org/reviews/silver-surfer)

Andy W
15-05-2006, 06:43 PM
It all depends on how much trouble you want to go to, I this afternoon had to recharge an Acson with R410 and only a suction valve, remove the casing of the unit and there will either be a charging stub sealed off or a shrader valve, mine had a shrader so no problems there. It was also only accessable by a ladder so a bit of a maul with vac pump and inverted gas bottle strapped to the ladder, like I said it all depends on how much trouble you want to go to. Also dont forget, you can use an atomizer quick charge, not a big fan myself but they do work if you are careful and go steady.

frank
15-05-2006, 06:53 PM
Hi Argus

Does your advice still stand if the unit is a heat pump with a suction accumulator?

Frank

gwilliamson
15-05-2006, 07:55 PM
More confused now than when i first asked the question.
So all these units that i fit currently ie. Daikin, Tosh & LG strictly speaking cant be charged with 410a if they dont have liquid connection? Please help?

slingblade
15-05-2006, 07:56 PM
This seems very familiar, i'm sure i posted on an almost identical topic where the o'brien oracle spouted about the near zero azeotropic properties of 410 when charging vapour. my solution was this, use a charge adaptor and then you wont have to stand the bottle in molten lava to increase pressure or flood liquid to the pot.

http://www.hvactool.com/catalog.php3?hcategory=1&hsubcat=6&hpagenum=1&hproductid=535-C

slingblade
15-05-2006, 08:01 PM
More confused now than when i first asked the question.
So all these units that i fit currently ie. Daikin, Tosh & LG strictly speaking cant be charged with 410a if they dont have liquid connection? Please help?


No not at all, charging liquid is ok if done slowly enough that it is vaporised before being compressed.

puddleboy3
15-05-2006, 09:38 PM
Most good quality systems have a port on the high and low side. From past experiance some engineers think if the access port is not on the service valve on the front of the unit then i doesnt have one! LOL.

Andy W
16-05-2006, 07:32 AM
Every system I have come across have at least a crimped piece of 1/4" copper adjacent to the condenser etc as that is how the factory weigh in the charge, some are shrader some are just sealed off, I would suggest start taking some of the panels off and having a look, sometimes on the cheaper units you have to remove the entire 1 piece machine cover which off a ladder can be awkward or time consuming, I was brought up in the old school way when I started 28 years ago, do it once and do it right and dont cut corners.

Think about it, even a domestic fridge will have a filter drier with a crimped off piece of pipe for factory charging.

Argus
16-05-2006, 09:28 AM
Hi Argus

Does your advice still stand if the unit is a heat pump with a suction accumulator?

Frank



Hi, Frank.

Generally yes, because the Accumulator on most small split heat pumps (that do not have liquid receivers, by the way) is there simply to accommodate the excess charge of refrigerant when the unit is working at reduced capacity in low ambient conditions in the heat mode. It is not a slop pot in the sense that accumulator tanks are placed at the coil exit in hot gas defrost systems to collect condensed refrigerant.

The accumulators have a finite size in relation to the total charge and there is a danger of it overfilling and flooding back when the liquid level reaches the open pipe. They are not sized to take a full charge. Additionally these things seldom have a heater, so even charging small amounts of liquid or sprayed droplets slowly will quickly remove any residual heat from the apparatus, leaving a body of un-evaporated liquid.

Small split systems sometimes have gauge access ports on the insides adjacent to the 4 way valve; typically one will be in the common suction pipe from the 4 way valve to the accumulator that allows suction pressure to be sampled in heating.

To my way of thinking, we assume that charging takes place in the cooling mode. Not always feasible in very cold weather when the unit is not capable of running. Using these stubs will simply result in charging into either the suction or against condenser pressure.
It?s far simpler to do it with the unit pumped down via the liquid line service valve as we have always done.
Most of these small splits are churned out in China and the Far East these days and the design is generally a compromise for the northern European market.

But, in reality and given the real world, charging R410A in vapour may not give a critical deviance from the design mix - but it's still a Zeotrope and not what the text book says.



.
________
Toyota NZ engine history (http://www.toyota-wiki.com/wiki/Toyota_NZ_engine)

Peter_1
16-05-2006, 02:09 PM
.
The quick way to wreck any compressor is to charge liquid into the suction – even small amounts can be hazardous for the compressor.
You cannot compress a liquid and damage will be the result.
.

Charged today +/- 180 kg R401a in the suction but I think you must know what you're doing...as allways.

Peter_1
16-05-2006, 02:17 PM
No not at all, charging liquid is ok if done slowly enough that it is vaporised before being compressed.
I'm with you Slingblade, as long as you do it very gentle.
Besides this, every compressor has special valves in it in case some liquid is entering.

Also the heat of the windings (suction gas cooled)vaporises a lot of the entering liquid.

And in the smaller hermetic compressors, if you open once a broken one, you will notice that it is a long way before the liquid can enter the discharge valves.

Everything can be broken but if you do it the right way, then litlle can go wrong.

Peter_1
16-05-2006, 02:19 PM
It’s far simpler to do it with the unit pumped down via the liquid line service valve as we have always done.

On the smaller hermetic units like l'Unithé Hermétique, there isn't such a valve and UH is a qualitative product.

slingblade
16-05-2006, 08:11 PM
I'm with you Slingblade, as long as you do it very gentle.
Besides this, every compressor has special valves in it in case some liquid is entering.

Also the heat of the windings (suction gas cooled)vaporises a lot of the entering liquid.

And in the smaller hermetic compressors, if you open once a broken one, you will notice that it is a long way before the liquid can enter the discharge valves.

Everything can be broken but if you do it the right way, then litlle can go wrong.


True enough. the one thing no one has picked up on here is system size. if i were to charge a 1/6 hp domestic via the suction with full bore liquid through a manifold then i would expect trouble more readily than say a 70 hp water chiller which would just swallow the gas as its no way near enough to cause damage, the trick to charging smallish plant is as ever "experience".

kevin090972
17-05-2006, 05:40 AM
Hi,

Most systems i come across have accumulators and if properly sized post no problem receiving all the liquid.

The rule here is to be very patient, if you charge liquid into the suction line, it will end up in the accumulator, it will take some time before it fully evaporate into a gas form.

Do nothing, wait, don't attempt to overcharge the system if it reflects a low pressure initially.

Make sure you pump the system down properly. If water moisture is present, it may ice up within the capilary tube causing some serious pressure issues during charging.

collo
25-09-2007, 12:48 PM
Gwilliamson, I do love your picci, I have wondered why we have apprentices on the job, now I know. LOL. This definitely passes all WHAS regs. I think the answer to your problem is as follows, CAREFULLY. As I cant find a way of getting gas or liquid into a piece of crimped copper, I guess I will have to keep on charging with liquid, As the man said .. secs on ..secs off, listen to the compressor. Alternatively weigh the correct amount of liquid in according to the data plate after recovering the existing gas and fixing the leak of course.(if there is one)
regards
Collo


Hi chaps, sorry for asking such a blonde question.
But what is the correct format for charging or topping up 410a refrigerant. Most a/c units now (splits) only have connections on the gas side and 410a must be charged in liquid form!?. What the correct way of safely perming a regas or adding extra?

adams?
27-09-2007, 01:15 PM
hi all, long time. in my expierience 410a splits dont need much additional gas so just calculate the extra charge and weigh it in using the vacuum in the pipework before running the unit up. what about charging stations? wiegh your 410a into the station in liquid state then happily sod off for lunch and a cuppa while the gas is sucked in. xxx

marcin2304
08-08-2008, 08:37 PM
can you talk?

marcin2304
08-08-2008, 08:40 PM
reinstalling two year old R410a cassettes

Brian_UK
08-08-2008, 11:39 PM
can you talk?


reinstalling two year old R410a cassettes
Please explain your posts as at the moment they do not convey much sense.

jrhvac
19-04-2010, 04:19 AM
howdy, on a new install that needs top up, can it be topped up with r410a..I heard from someone that r410a must never be topped up? I understand that liquid is the way of charging but what my source is telling me is not making much sense.

Peter_1
19-04-2010, 06:12 AM
Welcome on RE, you can top it off without any problem.
R410a is a zeotrope with an almost 0-glide.

nike123
19-04-2010, 06:37 AM
R410a is a zeotrope with an almost 0-glide.

Yes, but still need removing refrigerant from cylinder in liquid phase.;)

Ultimate Taz
19-04-2010, 07:18 AM
Hi there you can charge through the suction,you need to weigh in the refrigerant,bottle inverted add 20grams per metre

nike123
19-04-2010, 07:30 AM
Bottle inverted or not depend on bottle. There are bottles with tube from valve to bottom of bottle and they do not need to be inverted. It should be checked on bottle if it need inversion or not.

DTLarca
08-11-2010, 03:54 PM
In an epistemic sense R410A can be charged as a vapour.

Anyone who says it cannot must qualify this claim with an explanation.

That it is a zeotrope and all zeotropes have to be charged as a liquid is not an acceptable explanation - it is merely a paraphrasing of the first assertion.

Quality
08-11-2010, 05:29 PM
Because it say CHARGE AS LIQUID on the bottle:p

Contactor
09-11-2010, 12:21 AM
Can anyone explain how the imperial quick charge works, this is a great way to charge liquid

nike123
09-11-2010, 04:34 PM
Can anyone explain how the imperial quick charge works, this is a great way to charge liquid

Probably as simple as constant pressure expansion valve.


Internal Kwik-Charge metering element reduces liquid flow to a level below capacity of compressor. This assures a safe, fast charge without endangering the compressor

Quality
09-11-2010, 09:28 PM
Probably as simple as constant pressure expansion valve.

Even more simple than that

I cut one open , only to find layers of gauze/mesh and what I would call a disc with an hole in it.

a CPEV valve is pretty much the same cost, so its swings and round a bouts

dubati
14-11-2010, 06:00 PM
hi
please correct me if wrong, if charging vapor in a "nearly 0 glide" (still some then?) surley do this 1 or 2 times then you have a full bottle of r410a which is scrap??? ie a poor blend?

in my opinion i would charge liquid however VERY carefully/slowly using gagues as a restrictor so by the time the liquid enters the system is is more of a saturated vapour.

or charge whilst not running and leave to equalise!

hope this helps

oops looks like i'm a few years behind the first post hey ho my 2pence anyway :)

DTLarca
14-11-2010, 06:05 PM
hi
please correct me if wrong, if charging vapor in a "nearly 0 glide" (still some then?) surley do this 1 or 2 times then you have a full bottle of r410a which is scrap??? ie a poor blend?

in my opinion i would charge liquid however VERY carefully/slowly using gagues as a restrictor so by the time the liquid enters the system is is more of a saturated vapour.

or charge whilst not running and leave to equalise!

hope this helps

oops looks like i'm a few years behind the first post hey ho my 2pence anyway :)

Experiments showed that recovering R410A in vapour form 10 times in a row caused so little change in the component proportions it would be impossible to measure the effect on system performance - the change in proportions was also well within the manufacturing tolerances prescribed by ASHRAE.

DTLarca
14-11-2010, 06:13 PM
These are two contradictory statements from the following website...

http://www.epatest.com/R410A/manual/manual.jsp (http://www.epatest.com/R410A/manual/manual.jsp)

Should I charge R-410A as a liquid or vapor into a system?

Even though R-410A performs very similar to a single component refrigerant, it should be removed from the cylinder as a liquid to insure optimum and consistent performance.
If you have a leak from an R-410A system, does the entire charge have to be replaced, or can the system be topped off?

Since R-410A acts very much like a single component refrigerant, any change in composition due to a leak is minimal. The system can be topped off, without removing the entire charge. There is no practical limit to the number of times a unit can be topped-off or the refrigerant recovered from a unit. However, we do recommend that all leaks be repaired before topping a system off. Excessive superheat is an indication of low charge, and the possibility of a leak in the system should be considered.

dubati
14-11-2010, 06:14 PM
Experiments showed that recovering R410A in vapour form 10 times in a row caused so little change in the component proportions it would be impossible to measure the effect on system performance - the change in proportions was also well within the manufacturing tolerances prescribed by ASHRAE.

thanks for that!

paul_h
14-11-2010, 06:59 PM
Not this again. Liquid bomb the bloody thing in by weight if you know the charge, then go off and do your paperwork, make some phone calls, pack your gear up, have a smoke etc.
Run it in heat mode if possible when first firing it up, if not, hopefully you've had the power on to warm up the crankcase...
But if you've done any major work like a full reclaim and component changes, hopefully you've brazed in a schraeder into the condenser too to charge from in cooling mode before you start it up, as vaccing from one shraeder is crap anyway

cool runings
14-11-2010, 11:22 PM
Experiments showed that recovering R410A in vapour form 10 times in a row caused so little change in the component proportions it would be impossible to measure the effect on system performance - the change in proportions was also well within the manufacturing tolerances prescribed by ASHRAE.
.

You might be right..

410a has such a low glide it is somtimes termed near azeotropic.

The glide on 410a is only about 0.4 deg if im not wrong 404a is about 0.5 deg I think.... ;)

But for what it is worth...

All 400 series refrigerants should be charged as a zeotropic and in liquid form, then you will never make the mistake or suffer from seperation..

All the best

coolrunnings

.

nike123
17-11-2010, 12:22 AM
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410a has such a low glide it is somtimes termed near azeotropic.


Not sometimes, always.
And Yes, we don't want any separation during charging, and therefore, we should always charge in liquid state from charging cylinder. That does necessarily mean that liquid should enter system while charging. There are many simple means to avoid liquid in charging process.

DTLarca
17-11-2010, 01:05 AM
.

All 400 series refrigerants should be charged as a zeotropic and in liquid form, then you will never make the mistake or suffer from seperation..

Very true - if you only know that the refrigerant you are dealing with is of the 400 series, zeotropic, rather than of the 500 series, azeotropic, then you should always charge as a liquid. What this means is that whenever you are in doubt about the characteristics and nature of the refrigerant then you should play it safe and have the refrigerant leave the cylinder as a liquid.

But the question here is not about the 400 series per se but rather about a particular refrigerant from the 400 series. Because we are talking about a particular refrigerant - R410A - and no other - then there is no point in bringing up points that are relevant only to cases where you do not not know much about the particular refrigerant. In this case the question related to precisely the particulars of R410A and no other refrigerant.

Because you can recover and then charge R410A in vapour form over, say, 4 times and still have no effect that would be field noticeable it is then absolutely true that when charging R410A as a vapour just once the composition change will be so minuscule as to qualify as zero. Meaning transferring R410 in vapour form constitutes zero risk.

Committing the category mistake is a very common occurrence.
http://en.wikipedia.org/wiki/Category_mistake

animylapra
17-11-2010, 06:03 AM
No not at all, charging liquid is ok if done slowly enough that it is vaporised before being compressed.
Exactly...There is no any problem if you charging the liquid in small quantities at a time which should evaporate beffore entering to the compression chamber