Ice on refrigerant line at compressor causing wet floor

[Earl Dryer]

Customer complained of a water leak in the rear of refrigerator, removed access panel to suction line completely iced over.  The unit temperatures are good, the frost pattern on the coil is good. People just got this unit from their son, they nothing about it other than their got it at a scratch & Dent sale from HD and it came with the problem. HD sent repair person, who evacuated & recharged (1 BPV21) on the suction line. Thought maybe overcharge but no.  Removed access panel to expose the Evaporator, all appeared good in there, but low & behold the frosted suction line began to thaw, replaced the panel it began to frost over again. I know that restricted airflow will cause this condition but all is clear. I did notice that this coil appears to be too large for this unit, it is like almost pressed in, with zero clearance on the sides, the defrost heater has burned the cabinet liner at both lower sides of the evaporator. I'm stymed, any suggestions out there?  

Model MSD2732GRS

[jumptrout51]

Personally,I would solder in a schraeder valve and weigh in the charge.
As to the evaporator and heater, I don't know.
Does it appear to have been changed out?

[Earl Dryer]

I didn't weld in a new valve due to work area and location of the existing valve and the existing valve is tight.  As you may know 134a is difficult to get precise weight charge with 4oz. of gas that is why I use my ammeter while charging and adjust for 1.5 to 1.9
amp run. most times I'm real close.  When charging and sweep charging it is hard to measure exactly how must gas + water was removed and exactly how much gas remains in the system. I adjust the gas for best frost pattern with least current draw.  I did this on this box but like I said as soon as replace back on the freezer compartment my frost line advances to the compressor. 
The evaporator looks like the original. Interesting find was the insulating putty wrap normally around the accumulaor bulb was laying unused on fan housing (unused).
Reckon maybe this is one going under models, we don't care units?

[JWWebster]

Too much gas causes frost on the ear. Remove a tad.

[jumptrout51]

You might try wrapping the return line with cork tape.
My refrigerant scale made by Yellow Jacket weighs accurately within 1/2 ounce.

[tgoods]

How's the heat exchanger?  On a lot of the older Whirlpools the cap tube would separate from the return tube and cause the symptom you're describing.  On those I would cut off the insulation and use lots of zip ties to reattach the cap tube. Then rewrap with new insulation.

[Earl Dryer]

JWI did that already, no change.  Trout, my scale is also that accurate but a 1/2 oz is a pretty sizible over or under charge on a 4.25oz system. tgood the heat exchanger appear to intact, but you may have hit on something, it may be too short.  Where the heat exchanger leaves the cabinet it seperates, cap tube to the dryer and the suction line drops to form a 4" trap then loops around the condensor/fan assy. to the compressor
the overall length is approx. 18".
The puzzling part is why the line thaws when the evaporator cover is removed.

[Repair-man]

More than likely a partial restriction in the low side somewhere. This would account for the freezing of the line as though the unit were undercharged. The evaporator/heatexchanger should be replaced if you intend to salvage this unit. Not an easy task but can be done.

Opening the cover on the coil only exposed it to heat, something it was not getting on its own, even with the fan running. This is why I suspect a low side restriction, otherwise the line would not thaw  like that. In rare cases, the reed valves in the compressers (Embraco) were faulty and can  cause these symptoms as well. Check your run load amps on the running compressor.

[Earl Dryer]

The evaporator has an excellent frost pattern the run current is 1.76 amps on the compressor warm condensor and compressor dome.

[Repair-man]

Better weigh in a proper charge after changing the filter dryer (cut back 1" of cap tub) and see how it goes. The slightest over or undercharge will indeed cause weird frost issues down the suction line.