Strange things after compressor change.

[properdouble]

Hi
Guys i have changed recently danfoss compressor on a artica lockhart double door freezer and i put new LAE digitall controller with probes.After running thing seemed to be taking ages to go down with temp something silly like 4 hours to -20. Condenser clean suction pressure R404a about 1 bar i didn't replace sweat dryer, everything very hot including dryer like boiling hot i have evacuated for 45 mins. Thing is just not running as it should what could be the reason i had to overcharge it anyway to get it to work cause when i put labeled 550 grams pressure was about 4 psi way too low in my opinion.What you could be the reason probe on evap reading -26 and inside cabinet just -6.So something not right not sure what,what u think ?

[cold.man]

was it the same compressor as extracted?
drier should of been replaced !!!! standard procedure when replacing compressor.
sounds like you have contamination in the system.
replacing the probes and controller should't really have any effect on the system.
like i say drier requires replacing and even a tripple evacuation of the system and more importantly ensure you have the correct compressor.

[monkey spanners]

I hate it when a comp change goes strange.

First question you should ask is what killed the first compressor?

The symptoms often point you in the direction of the cure, in your example you have a lower than expected suction pressure and an apparently high discharge, you have weighed in the correct charge (and some) so that rules out low charge as a cause of the low suction pressure, so this either the compressor is pupming too much (oversized or the refrigerant can't get round the system quick enough.

Those copper spun driers block up for fun so thats a favourite, as is the first part of the cap tube if craps got in. Think i'd change this and possibly cut off a bit of the cap tube (not with wire cutters as it'll get squashed, file a nick in it and snap it, clean the end with a stanley blade if needed)

Purge with ofn while brazing, don't take much copper oxide to bung these up either.

Vac and recharge, cross fingers and turn on and see....

[properdouble]

Hi
Compressor was exactly the same.I have done few and it never was like that i know that i should have changed drier my bad. Was thinking of all this but eventually is working and customer didn't complain since so iam waiting what will happend.If they call then i will go and change drier possibly purge system. Just wanted ask cause it felt so strange as hell. Hate contaminated or partially blocked capillary system it just take so much time to get it up and running as it should . turns out to be expensive too wich dosen't help with customer satisfaction..

[Brian_UK]

Also,
i have evacuated for 45 mins doesn't really provide evidence of a good vacuum level. It is a pressure reading that decides that, not time.

[cold.man]

as brian_uk said you cannot just guess by time if you have acheived a sufficient vacuum level.

are you using a torr gauge when carring out the evacuation of the system and acheiving a 2 torr vacuum.

on a small system such as the integral double door chiller which you are working on it will not take long to acheive a 2 torr vacuum. and using a torr gauge you will be able to determine if you have any contamination in the system more efficiently.

[cadwaladr]

not changing drier after comp change is foolish to say the least,why did the comp fail and what gas is it on? was the original comp the correct one i have seen this mistake before,ofn vac drier change and dont rush it fail to prepare,prepare to fail!.

[install monkey]

evap -26 cab -6 check your door switch for the evap fan, check the fan works,is the freezer empty,door seal good- good airflow around the cab- prob overcharged-test the td accross the drier as others suspect drier
Hi
Guys i have changed recently danfoss compressor on a artica lockhart double door freezer and i put new LAE digitall controller with probes.After running thing seemed to be taking ages to go down with temp something silly like 4 hours to -20. Condenser clean suction pressure R404a about 1 bar i didn't replace sweat dryer, everything very hot including dryer like boiling hot i have evacuated for 45 mins. Thing is just not running as it should what could be the reason i had to overcharge it anyway to get it to work cause when i put labeled 550 grams pressure was about 4 psi way too low in my opinion.What you could be the reason probe on evap reading -26 and inside cabinet just -6.So something not right not sure what,what u think ?