Cooler charge confusion

[Matadem]

Hi
I've recieved 2 small coolers that doesn't cool
both same brand both brand new.

1/6th hp compressors, 134-A, 4.6oz, 2.5 amps on the
sticker inside (but 2.9 amps on their website)
These were shipped from outside the US that is why
the owner didn't want to return it. $$$

So I hook up the manifold nothing... no refrigerant
I see where the access valve is there is a hole where is bends ...so this unit could have never been tested...

fix the hole...blew the capillaire to make sure it was not clogged... replace the filter/drier

Charge to manufacturer specs 4.6oz...not cooling at all...so now I am confused and I am thinking maybe
my weight scale is playing tricks on me... so I weigh my bottle ....charge the unit again to 4.6oz ...then check weight again...seems correct but still no cooling :/

so I continue to fill the unit to about 20F and the unit cools now... reaches 44F which is still not satisfactory

the other cooler has refrigerant in it but doesn't cool
so I charge it to 20F and it ices up... contacted the manufacturer told us to charge to 25F still ices up
charged it to about 30F the cooler reaches 48F but will not go any lower...

anyone have some suggestions to these problems
anyone have some ideas what the superheat/subcooling would need to be for these small appliances I would like to really know what the problem is with these units

ambient temp here is about 82F it is any help...

any help would be apreciated
Thanks

[nike123]

Give us make and model#!

[Matadem]

Cooler info
Ascend
JGD-06R
s/n:GC6R-0908-0235
6 cu ft.

Thanks

[nike123]

http://www.ascendmfg.com/PDFs/JGD-06R&06R-PT.pdf

Maybe they fitted incorrect capillaries. What is compressor make and model #.
Remove charge and fill amount stated at sticker than measure superheat, pressures, inside and outside temperature, discharge line temperature condenser outlet line temperature and filter-dryer temperature and post here.

[Matadem]

Compressor info:
LG NS36HAQG
1ph 110-115V 60 Hz
LRA12 134-A
CP17120091060141

Charged the unit again at 4.6oz
after 20min the pressure is stable at
sp 20psi - 22F
superheat 73F-22F=51F ???
Ambient temp 78F
inside cabinet temp 60F
Filter/drier temp 99F
inlet condenser 106F
outlet condenser 102F
inlet evap 36F (evap starts freezing)
outlet evap 73F
inlet compressor 86F at 2" distance
outlet compressor 137F at 2" distance
inlet evap fan suction in cabinet 60F
out evap fan blows in cabinet 53F

amps at 2.3A

This is all the readings that I took.

Thanks

[Gary]

What are the condenser air in and air out temps?

[nike123]

LOW CHARGE = High superheat. Low suction pressure, indoor TD, subcooling, head pressure & compressor current draw.
MILD RESTRICTION (factory charge) = High superheat. Lowsuction pressure, indoor TD & current draw. Normal to high subcooling. Normal to low head pressure.

I vote for low charge.

Add charge by no more than 1-2% of amount already in (critically charged system like your is very sensitive to charge amount).

Leave unit to work for 20-30 min and check again all readings as before.
Specially monitor suction line temperature after topping up. When you are near or at correct charge suction line temperature should start dropping very fast. Then it will rise again if you overcharge it.

http://www.refrigeration-engineer.com/forums/%5BIMG%5Dhttp://i40.tinypic.com/qn8h6s.jpg%5B/IMG%5Dhttp://i40.tinypic.com/qn8h6s.jpg

If careful topping don't bring much results than your capillary tube is probably too long or too small diameter.

If you really want to sort it out easy than braze some process tube with access port at high side and monitor high pressure and subcooling. If subcooling is low, you have low charge, if high, you have restriction and refrigerant collecting in condenser.
Later you could crimp process tube few times and with crimp pliers still pressed at last crimp, cut access port and weld pipe fast with silver.
Leave at least 10 cm between last two crimps and cool pipe with wet rag during brazing.

P.S. Take readings of temperature of pipes at least 10" from compressor.

[Gary]

LOW CHARGE = High superheat. Low suction pressure, indoor TD, subcooling, head pressure & compressor current draw.
MILD RESTRICTION (factory charge) = High superheat. Lowsuction pressure, indoor TD & current draw. Normal to high subcooling. Normal to low head pressure.

I

This holds true only if/when the box is down to design temp, especially on a cap tube system.

If it is cooling, wait for the temp to come down, then take a new set of temp readings. On an intial pulldown with high humidity, this could take overnight.