Charging the system

[CJG21]

Apologies for asking what is probably a very simple question but I'm a first year apprentice still trying to get my head around this trade :D. Anyway, was wondering if a system is severly overcharged, what are the ramifications? Does it mean that the evaporator temp is too high and does it put any of the other componenets under stress? Can I also ask the same question but for a system that is undercharged? Thanks in advance for any advice given

[The MG Pony]

Over charge over works the compressor and shortens life time, under charge system cycles are shorter over working thermistat contacts and stressing compressor yet again shortening its life.

[Peter_1]

TEV or capillary system?

[lana]

Hi Colin,


Apologies for asking what is probably a very simple question but I'm a first year apprentice still trying to get my head around this trade :D. Anyway, was wondering if a system is severly overcharged, what are the ramifications? Does it mean that the evaporator temp is too high and does it put any of the other componenets under stress? Can I also ask the same question but for a system that is undercharged? Thanks in advance for any advice given

If Overcharged :
1-Suction pressure High (i.e. , evaporating temperature High)
2- Discharge pressure High (i.e. , condensing temperature High)
3- Super heat Low for cap tube system. If TEV is used then it depends on the amount of overcharge. If the system is too much charged then super heat would be Low.
4- Sub cooling high

If Undercharged :
1-Suction pressure Low (i.e. , evaporating temperature Low)
2- Discharge pressure Low (i.e. , condensing temperature Low)
3- Super heat High
4- Sub cooling Low

Be careful : If there is non-condensibles present then you will have the exact symptoms of "Overcharged" fault. The only way to distinguish between them is to do "Non-Condensibles" Test.

If evaporating temperature goes up (I mean more than the design value), then cooling capacity decreases. Also, this means that the compressor amp will go up. All depends on the amount of increase or decrease really.

Hope this helps.
Cheers

[CJG21]

Hi Colin,



Be careful : If there is non-condensibles present then you will have the exact symptoms of "Overcharged" fault. The only way to distinguish between them is to do "Non-Condensibles" Test.

If evaporating temperature goes up (I mean more than the design value), then cooling capacity decreases. Also, this means that the compressor amp will go up. All depends on the amount of increase or decrease really.

Hope this helps.
Cheers

What do you mean by the non-condensibles test?

[lana]

Hi to you too,
Please read the link below :
Its Post #5.

http://www.refrigeration-engineer.com/forums/showthread.php?t=7328&highlight=condensible


Cheers