Results 1 to 29 of 29
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28-10-2004, 07:53 PM #1
Celler Cooling A/C or Refrigeration
Hi Guys,
When does a/c become refrigeration and vice versa
Why do i ask
Today i got called to a celler cooler in Norwich which turned out to have a seized compressor
The condensing unit is a Eaton Williams, J 97643-02 S/N Q08591 2003
Now the compressor is a L'unite Hermatec RK5515C R407c 240v which according to the NRS book is an a/c pot
Now the system is much like an a/c system, boxed indoor and outdoor unit. all that has to be done is pipe and wire between them. No drier.
Which brings me to another question, why do a/c units never have driers on them. Bi-Directional one's readily available from all stockists.
I have asked the office to quote for a pot, liquid & Suction driers as the unit is cool only and the reclaim and use fresh gas.
So many questions, too slow typing speed
Regards
FatboyLast edited by Latte; 28-10-2004 at 07:58 PM. Reason: spelling - fingers too fat fot keys
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28-10-2004, 08:04 PM #2
Re: Celler Cooling A/C or Refrigeration
A lot of packaged a/c condensing units already have driers built into them - they're not big but are there - more like a cap line drier size.
Brian - Newton Abbot, Devon, UK
Retired March 2015
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28-10-2004, 08:13 PM #3
Re: Celler Cooling A/C or Refrigeration
Hi Marc,
Remember, it is me you are talking to
Originally Posted by Marc O'Brien
Can you translate this from technical director level to basic engineers level
Thanks
Ray
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28-10-2004, 08:58 PM #4
Re: Celler Cooling A/C or Refrigeration
eaton williams bought the remains of qualitair (my first employer)
their cellar cooler (used to be QKK -err 'qualitair keller kooler')
was basically an air conditioning condenser with a different (noisy) evaparator..
anyway all a/c's have a drier but it's a tiny copper spun one..
I remember when the japanese first came over and we used to see loads with a drier -plus a sightglass- fitted in the expansion line
cheers
richard
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28-10-2004, 10:56 PM #5
Re: Celler Cooling A/C or Refrigeration
Hi Guys,
Thanks for the replies, so what is the consensous of opinion on the drier front.
I am tempted to fit one with a sightglass on the liquid line, anyone disagree with this
Regards
Raymond
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29-10-2004, 01:19 PM #6
Re: Celler Cooling A/C or Refrigeration
Which brings me to another question, why do a/c units never have driers on them.
Does your outdoor unit have an EEV or capillary? If not then you can safely fit both a drier and sight glass. A sight glass fitted after the metering device is just a waste of £'s.
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29-10-2004, 02:12 PM #7
Re: Celler Cooling A/C or Refrigeration
Hi Raymond.
In the manufacturer catalogue, you will see for each compressor model, the minimum evaporating temp. This one can go as low as -10C (evap. temp.)
It is not important if you call it refrigeration or AC, its the working conditions that count.
According to the manufacturer, this is an AC compressor and its the firs time I've heard that it is used for refrigeration.
AJ 5515C or AJ5518C will do a better job depending on your evap. temp.
Chemi
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29-10-2004, 06:56 PM #8
Re: Celler Cooling A/C or Refrigeration
Originally Posted by rdocwraBrian - Newton Abbot, Devon, UK
Retired March 2015
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29-10-2004, 09:23 PM #9
Re: Celler Cooling A/C or Refrigeration
Hi Guys,
I cannot remember see a metering device on the outdoor unit.
I will get a drier and sightglass just in case and will also check the evap just to make sure there is either cap tube or an expandion valve inside.
regards
Fatboy
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29-10-2004, 10:37 PM #10
Re: Celler Cooling A/C or Refrigeration
Hi Raymond,
I do not believe that a manufacturer will not put as a standard equipment, a drier and sight glass.
What I do believe, is that the person who installed it at the first place, didn't.
If there is a cap tube, you will see the drier just before it.
In AC splits, there is no drier and many people, by mistake, think that what they see before the cap tube is a small drier. It is not. What it is, is a very fine filter to keep the cup tube clean.
Chemi
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30-10-2004, 05:36 PM #11
Re: Celler Cooling A/C or Refrigeration
Not quite true Chemi. See this link http://www.spincometal.com/mp_driers.htm
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30-10-2004, 06:13 PM #12
Re: Celler Cooling A/C or Refrigeration
Thanks Frank.
I have learnt something today.
The local manufacturers do not use them.
I have this practice that when a cap tub is blocked, the first thing I check is that filter. Never saw anything else but the fine mash inside.
Every day you learn something new!
Chemi
P.S. Isn't it CELLAR?
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30-10-2004, 06:45 PM #13
Re: Celler Cooling A/C or Refrigeration
Marc
Next time God is dishing out the brains............please dont be selfish, leave a little for " us" as well !!!!Any opinions, statements and facts expressed in this message do not constitute legal advice in any shape or form and is given for a general outlook in nature. You are advised to seek appropriate and specific professional assistance from a regulated and authorised advisor for definitive advice.
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30-10-2004, 08:33 PM #14
Re: Celler Cooling A/C or Refrigeration
Originally Posted by Marc O'BrienIt's better to keep your mouth shut and give the impression that you're stupid than to open it and remove all doubt.
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30-10-2004, 09:49 PM #15
Re: Celler Cooling A/C or Refrigeration
Hey folks,interesting discussion ,if you have a cap tube and
and increase volume after the condenser you will move the
balance point for the amount of refrigerant you should put
there,its important to have the right condition to inlet of the
cap tube,because of the two-phase flow calculated by the
factory.If this is an old secondhand compressor you better
check for acids by oiltesting and choose a small laying filter
which take care of acid/water.I dont try to learn you something you know, I am only interested in subjects like this.
Have nice day! norcoolnorcool
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30-10-2004, 11:31 PM #16
Re: Celler Cooling A/C or Refrigeration
when God was giving out brains, i thought he said "trains" and i said "give me a slow one, that goes chug chug."
cheers
eggs
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30-10-2004, 11:43 PM #17
Re: Celler Cooling A/C or Refrigeration
you got it, tiger.
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30-10-2004, 11:48 PM #18
Re: Celler Cooling A/C or Refrigeration
Originally Posted by Peter_1
There's none so queer as folk dear
except thee and me,
But you're a little bit funny yourself.Brian - Newton Abbot, Devon, UK
Retired March 2015
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30-10-2004, 11:59 PM #19
Re: Celler Cooling A/C or Refrigeration
i'd watch it if i were you, cos i know a poem aswell.
Roses are red
Violets are blue
i used to be schizophrenic
so did i.
cheers
eggs
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31-10-2004, 04:54 PM #20
Re: Celler Cooling A/C or Refrigeration
Every day you learn something new!
P.S. Isn't it CELLAR?
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31-10-2004, 05:19 PM #21
Re: Celler Cooling A/C or Refrigeration
Hi Frank,
It takes years to understand that to say you do not know something and asking for explanation is the best and quickest way to learn!
We all was different when we were young.
The biggest task of us grown ups is to try and help those young ones who "knows it all" to learn how to take one step at a time. That is, if they are keen to learn.
Chemi
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05-11-2004, 06:56 PM #22
Re: Celler Cooling A/C or Refrigeration
Hi Guy's
Just to report back on the original job. Went back today, checked the indoor unit and it was a Qualitair/Eaton Williams unit with cap tube in the indoor unit so i changed the pot, cut the pipes coming out of the condensing unit and fitted a liquid drier and sightglass and also i suction drier. Vac'd and charged all OK. Original unit charge 1.1kg but a very long pipe run and it ended up taking 1.8kg. Sightglass clear & pressures spot on.
Regards
Fatboy
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05-11-2004, 11:25 PM #23
Re: Celler Cooling A/C or Refrigeration
Originally Posted by Marc O'Brien
He's using the liquid line drier as a receiver and the suction line drier is propably oversized to act as the accumulatorBrian - Newton Abbot, Devon, UK
Retired March 2015
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06-11-2004, 12:09 AM #24
Re: Celler Cooling A/C or Refrigeration
Hi Guys,
Originally Posted by Brian_UK
For the record, at 1.1 kg the unit was going out on LP due to one of them stupid solder in preset things hence i added an extra 0.7kg.
The unit is in a large hotel, the outdoor unit one end, the cellar the other. 3/8 discharge, used 083s drier as system smelled burned and wanted to put a fairly big one on and a 165 suction drier (Sporlan of course )
regards
Raymond
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06-11-2004, 11:23 AM #25
Re: Celler Cooling A/C or Refrigeration
A clear sightglass on a cap tube system is cause for concern. It probably means the system is overchanged.
This is why cap tube systems should not have a sightglass. When service techs see a sightglass, they want to clear it.
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07-11-2004, 05:59 PM #26
Re: Celler Cooling A/C or Refrigeration
Hi Guys,
Popped back in today to check unit now it's had time to get the temp down in the cellar.
Pressures still spot on but sightglass only 1/2 full. didn't put any more gas in following garys post.
can someone tell me why you shouldn't put a sightglass in a cap tube system
Cheers
Raymond
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07-11-2004, 09:50 PM #27
Re: Celler Cooling A/C or Refrigeration
Hi Raymond
The cap tube is a fixed expansion device and does not meter the refrigerant as you would get with a tev as the load changes. The whole point of a sight glass on a system with a tev or eev is that you can check the quality of the liquid refrigerant feeding the expansion device. What you don't want is bubbles ( a mixture of liquid and vapour) as this will lead the valve seat to wear prematurely, and make it difficult to fill the evaporator correctly.
With the cap tube the refrigerant can only feed the evaporator at a set level no matter what the load is. You should charge a cap tube system based on the superheat only. At different stages of the cycle when the system is charged correctly you will get varying levels of refrigerant quality feeding the cap tube and with a sightglass you will see different things at different times of the cycle. If you charged the system to a full sight glass at, say, pull down, then at low loads you will be overcharged and this will put extreme pressure on the compressor. As cap tube systems are small this will lead quickly to compressor failure.Last edited by frank; 07-11-2004 at 09:53 PM.
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08-11-2004, 05:35 AM #28
Re: Celler Cooling A/C or Refrigeration
i somtimes wonder wether some people went to trade school maybe they forgot or wagged that day. Cap system is critical charge it will starve a hot coil and definetly not show full glass s/g on cap system waste of money either start from scratch and add manufactures quantity or ref. This will only be problem if system has been altered in some way. Most usual prob occurrs with comp change if not exactly the same comp if is diff brand but capacities add up exact or nearly exact it still can b prob as the dont all rate them quite the same. If in doubt u have to spend the time to check operation at or very near to cycling temps by checking super heat or frost line or sweat back depending on system. due to these generally smaller herm comps u dont want flood back and if that horrible R22 u dont want too much superheat.this is y most mech much perfer auto type expansion devices quicker and easier to charge. Those who did apprenticships doing domestics know which is the easyer by far to work on commercial much easier
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08-11-2004, 05:50 AM #29
Re: Celler Cooling A/C or Refrigeration
IN REGARDS to drier or strainer in spun cu ive seen both u have to ask manufacturer or cut it open.
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