Charge only with liquid.

[Grizzly]

Despite this statement being printed upon certain of the newer refrigerant cylinders.
I with few exceptions when charging from a vacuumed system.
Break the vacuum with Vapour to 0c/ relative prior to adding refrigerant in a liquid state.
(Through a manifold gauge so that the refrigerant leaves the cylinder in liquid form)
Sorry to the 2 posts below I did not make that clear.
Is it just me or do most adopt this practice?
Cheers Grizzly

[chillerman2006]

Hiya Grizzly

I always charge liquid, just I bleed it (restrict it) through my gauges

[nike123]

Liquid must exit from charging cylinder.
What you do from that point is your free choice.

[r.bartlett]

Dump charge the lot from a vacuum then go have a cup of tea. Come back refreshed and she's good to go. :-)

[sedgy]

yes must agree with all the above posts , but I must add < cos I aint seen it on this website< that on water chillers, vapour must be first added up to Oc, with water pumps running to stop any freezing of water before adding liquid,
sedgy ,

[chillerman2006]

< cos I aint seen it on this website< that on water chillers, vapour must be first added up to Oc, ,

See the 1st post by Grizzly

[sedgy]

hi chillerman , my point wasent about adding vapour up to Oc but about liquid charging on water chillers
sedgy,

[chillerman2006]

hi chillerman , my point wasent about adding vapour up to Oc but about liquid charging on water chillers
sedgy,

hi Sedgy

So was grizzlys post, and you wrote "cos i aint seen it on this website"

He is industrial and chillers same as me

i wrote "I always charge liquid, just I bleed it (restrict it) through my gauges" but that was obvious to those who work on larger systems that I also only do this till 0c (I Hope !) and then dump it in, other wise I would be there all week still charging

Thats twice I have done that today now - presuming

Presumption is the mother of all f*kups - once again

[james10]

samll a/c systems liquid straight away
VRV/VRF as above
racks/packs liquid straight in to condenser isolated then bleed through in to the rest of the system
chillers/heavy industrial vapour until 0c then liquid

[sedgy]

chillerman , no grizzlys post dosent mention waterchillers
and no I did,nt know you and grizzly is industrial and chillers,
ad so you dont add vapour only up to Oc? I am supprised that an expert of your standing dosent do that?
yours sedgy,

[chillerman2006]

chillerman , no grizzlys post dosent mention waterchillers
and no I did,nt know you and grizzly is industrial and chillers,
ad so you dont add vapour only up to Oc? I am supprised that an expert of your standing dosent do that?
yours sedgy,

RE Friend

Think we are both miss understanding each other here

I do charge vapour to above 0c on water chillers to avoid freezing the vessel and also higher with 400 series refrigerants to account for the glide

I am racking my limited brain here and I can not think of any other application I would need to take this precaution

Maybe some one with more experience could educate me

[joe-ice]

guess it wouldnt matter which way if your putting in the full cylinder,

[sedgy]

hey chillerman ,
we are all here to expand our knowledge allthough retired stll like to have a feel for the job ,
misunderstanding each other, yes = I allways added vapour to w- chillers uo to O c < not over O c< many years ago westinghouse stated that all their chillers must be gassed up to their standards< we where the uk agants < commac m/c< so there is where this practice comes from .
all the best for now , sedgy,

[chillerman2006]

hey chillerman ,
we are all here to expand our knowledge allthough retired stll like to have a feel for the job ,
misunderstanding each other, yes = I allways added vapour to w- chillers uo to O c < not over O c< many years ago westinghouse stated that all their chillers must be gassed up to their standards< we where the uk agants < commac m/c< so there is where this practice comes from .
all the best for now , sedgy,

Hi sedgy

the 400 series refrigerants have different temperatures at a given pressure for vapour and liquid

bit of a pain really

for example

R407c is quite common now in a/c chillers

@3.6 bar.g the vapour is at 0c but the liquid is minus 6.5c

when charging in vapour i take it up to 4.7bar.g which is just over 6c

Retired ! you lucky devil

[install monkey]

i charge a vacuumed system slowly up to 0psig then slowly after that too to disturbing the oil in the compressor also to maintain oil temperature and also observe its operation afterwards,whilst drinking lots of coffee then slowly driving home because i get paid off my trusty tracker ! so the longer i take the more it pays! simples haha

[Turbo2212]

I always charge in liquid state just to save confusion and purge it through the gauge manifold or bomb the receiver before hand. Zeotropes have a combination of refrigerants in a blend that boil under different temperatures and pressure's so if you were to charge a zeotrope eg. 404 and 410 in vapour state the blend wouldn't be divided accurately enough between refrigerants in the system.

[Grizzly]

Hi Turbo.
What do you mean by "Bomb the Receiver"?
"Bomb" is a term used for NDT Testing down my way!
Just to clarify, I have been taught where water is in contact with the refrigerant pipework.
In say a shell and tube evaps or condenser etc.
You charge to 0c to prevent Ice crystals forming and crushing the copper tubes within.

We all know about blends and why it's necessary to charge from the cylinder in Liquid form.
If practicable I and many of my colleagues do the same on other equipment out of habit.
As has been pointed out by others on this post it is not "technically" necessary.

A marine application is one of the worst for tubes being crushed.
Where the tech forgets that in dry dock the shell and tubes usually filled with sea water are empty.
So the ice crystals formed crush the tubes with alarming results.
So in fairness to all, knowledge of the particular system you are working on is paramount.
Grizzly

[chillerman2006]

Hi Turbo.What do you mean by "Bomb the Receiver"?............, knowledge of the particular system you are working on is paramount.Grizzly

Hi Grizzly

dont know if 'Turbo' & I speak the same jargon

when I use a similar term, I mean discharge & liquid line valves closed

and knowing roughly what the condensor holds (air cooled) just open the lines & bottle in liquid form & 'bomb' it in

am sure you do this anyway mate

done abit of marine(navy) too, where they would not even let me use my soldering rods, had to be theirs, to their spec & they stand over you from start to finish, watching your every move...... not a comfortable way of working

R's chillerman

[Grizzly]

Hi CM.
Thanks for the explanation.
I learned something there, I have done similar where appropriate. I don't remember ever shutting the discharge though?
As they say you learn something new every day!
I learned today that if you have 2 identical split systems in the same room and you accidentally connect the indoor to outdoor Com's cable to the wrong unit.
Both work fine until either are shutdown then the remaining running unit goes out on P8 fault (Mitsi).
As each is using the others evap and as the one shuts down the resultant liquid flood-back shuts the remaining running unit down.
DOOH!
A hour to identify and 10mins to rectify.
The cables had crossed each other on the cable tray and neither I nor my colleague had noticed Honest!
I miss the navy work usually a good set of lads and once they had got to know you you left to get on with it. But yes they are strict on protocol and regimes.
Well at least they used to be!
Cheers Grizzly.

[chillerman2006]

Hi Grizzly

wat are they playing at ? I know works work, but what a waste of knowledge & skill having 'you' tinkering with an install.. the last I did took me sooo long compared to an experienced installer, was never asked again the main problem I have with installs is being too pedantic..... bet your doing a good job though, without a hair out of place

only shut the discharge on recips mate... heard a horror of valves going on start-up, so just being cautious, yet again !

R's chillerman

[Grizzly]

Ah Now I understand.
Long gone are the days when one area of expertise was all that was covered.
You should know that my friend.
The installs (6 in all)were really quite interesting and it makes you appreciate how varied refrigeration work can be.
Respect to the split guys, thankfully I have not gotten involved with VRV or VRF's yet.
I am lucky I have a wealth of knowledge available here on the forum, should it be needed.
The really clever guys on here are not necessarily the ones always in print they have to be coaxed of the fence.

You Know what they say variety is the spice of life.

It strikes me no matter what size of system, there is still that daunting feeling whenever you turn the system on for the first time.
Take care CM, the commutes are still tolerable I hope?

For those of us in the South West, it should be much quieter next week as it's Half Term Week.
Grizzly

[chillerman2006]

Hi Grizzly

should know better, yes them days long gone, even ICS & Service4Chillers lads I spoke to the other day are getting a/c work now.... the commute is still a pain, so such so that may take one of two positions that are local, gshp service or small commercial as both pay travel & later starts, installs are so far outer my comfort zone now, would not where to start, horses for courses as they say

and nice to know some will have less traffic next week, as London's day time traffic increases for the week

at least its only 4 days though as have one of cause am 31 again next week

R's chillerman

[frederik79]

Hmm i usualy make sure the pri pump is on and charge the system on the discharge or liquid line.
Always in liquid form..
Am i doing something wrong ?

chillers

[nike123]

How you ensure that charging cylinder pressure is higher than discharge pressure. Heating blanket or recovery pump or something else?

[simon@parker]

How you ensure that charging cylinder pressure is higher than discharge pressure. Heating blanket or recovery pump or something else?

mapp gas dont scorch the bottle though