Excessive frosting @ evap. inlet !!!!!

ACE

Appliance Tech
Joined
Jun 29, 2005
Messages
42
Location
Montana, USA
Model Number
FAL124M1A1
Brand
Frigidaire
Age
1-5 years
I've changed out the compressor....

Blew out the lines....

Cleaned the fins....

Still get the same result @ the very beginning.

Frost buildup @ the inlet to the evaporator!

This is a Frigidaire. (FAL124M1A1) 12,000 Btu A/C

L.S. PSIG=38 H.S. PSIG=175

No cap restriction.

Is it possible to have an evaporator restriction, and if so, what in the world is floating around those lines to cause a restriction in tubing that large!?

P.S. This person was a heavy smoker, and the fins were originally blocked up from the smoke, and dust. (What a lovely smell when the unit blows in your face!) :p
 

jeff1

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Messages
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Location
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Hi,

**Still get the same result @ the very beginning. Frost buildup @ the inlet to the evaporator!**

-Just- at the beginning and once the unit has been on a while the frost disappears and you get sweating on the evap coils??...if yes, this is normal.

Rotary compressors do not pump well for the first 5-15 minutes and take a bit to get going.

**L.S. PSIG=38 H.S. PSIG=175**

LS pressure running should be more like 50-60PSIG back pressure....I don't measure the high side when running as it will likely be 250+ PSIG

jeff.
 

ACE

Appliance Tech
Joined
Jun 29, 2005
Messages
42
Location
Montana, USA
Nope...... The frost will continue on its downward spiral towards a nice chunk of ice.

......half way throughthe evap.

There's no heavy sweating nor frost of any type @ the 2nd half of evap.

The suction line @ the comp. is about ambient.

The humidity is not high.
 

jeff1

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G'day,

**There's no heavy sweating nor frost of any type @ the 2nd half of evap**

More than 1 feed into the evaporator? Have had a couple of newer ones only work on 1/2 of the evap and I had a restriction that blocked one of the feeds ( oil ).

Do get the charge up higher when you retest the unit.

jeff.
 

ACE

Appliance Tech
Joined
Jun 29, 2005
Messages
42
Location
Montana, USA
Yea... 2 feeds.

What do you mean .....get thechargehigher?

Nitrogen? or freon?

I don't wanna overcharge!
 

jerryjay11

Premium Member
Joined
Jul 3, 2005
Messages
8
Location
, ,
There are 3 questions I would say to answer.

1) Why did you change the compressor in the first place?

2) Did you check the screens where the cap tubes enter the evap coil?

3) Did you either use a charging cylinder or accurate scale to weigh the charge in?
 

jeff1

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ACE wrote:
Yea... 2 feeds.

What do you mean .....get the charge higher?

Nitrogen? or freon?

I don't wanna overcharge!

Refrigerant gas.

**L.S. PSIG=38 H.S. PSIG=175**

LS pressure running should be more like 50-60PSIG back pressure when fuly charged....I don't measure the high side when running as it will likely be 250+ PSIG

-Sounds- like something is still restricted as well :(

jeff.
 

ACE

Appliance Tech
Joined
Jun 29, 2005
Messages
42
Location
Montana, USA
I changed it because it was loud, and drawing a higher than normal amperage....

So I assumed that the compressor was weak.

I am unaware of screens at the evap. inlet.

The filter drier was changed.

I used a scale. Refrigerant charge is perfect.
 

jeff1

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**I used a scale. Refrigerant charge is perfect.**

Pressures posted are still low :(

jeff.
 

ACE

Appliance Tech
Joined
Jun 29, 2005
Messages
42
Location
Montana, USA
I am replacing the evaporator today.... Will report my results tomorrow!



Unless the serial tag had a misprint, my refrigerant charge has always been correct.
 

jeff1

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**Will report my results tomorrow!**

Great :)

**Unless the serial tag had a misprint, my refrigerant charge has always been correct**

What pressures do you usually see on the low side?

jeff.
 

ACE

Appliance Tech
Joined
Jun 29, 2005
Messages
42
Location
Montana, USA
Success!!!

L.S. = 32 psig H.S. = 210 psig

The old evaporator was oil slugged! This explained the slight bounce on my low side gauge!

Coils are now uniform!

Well..... I'm onto a freezer now.

Have a great day!
:D
 

jeff1

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**The old evaporator was oil slugged!**

Ooops!

**L.S. = 32 psig H.S. = 210 psig**

Glad it works...still appears low to me :?

jeff.
 
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