I just fixed a Bain Marie. The compressor was trying to start - current relay cycling on then off every few minutes. I used my finger nails to hook on to the 1/4" thick piece of felty sludge that was on the condensor coil and peeled it off in almost one piece, leaving a nice clean condensor coil. (yuk) I turned the unit off and let it cool.
Once I powered it up again, the compressor started and it ran continuously but it wouldn't pull down to temperature and there was ice forming on the liquid line after the capillary tube. So I figured it's under charged but I don't know what refrigerant is in the unit. The refrigerant plate is blank, compressor says R12.
I recovered 3.4ounces of system refrigerant via the access port mounted on the compressor until system pressure was 15" vacuum, performed a pressure test, evacuated, and then put 8 oz. of HotShot2 in the system to obtain 35psi suction pressure with 5degrees superheat. HS2 is supposed to work with mineral oil, AB, or POE so I didn't change oil.
The amount of refrigerant recovered seems real small, and the amount used to charge it to 5degrees superheat seems really small as well. Does this make sense? Granted the unit is small - evaporator measured about 10" by 8", but 8oz makes me think I only got the refrigerant on the low side of the capillary tube.
I'm an AC guy and new to these tiny little systems so I don't know what a typical charge is, and like I said the plate was blank. As of now, the unit is working.
Anyone used HS2 yet? Is it good? Anyone work on these small Bain Marie things? Is my charge screwed up?