Refrigeration system repair

This page is about medium temperature reachin boxes.  These coolers are usually meant to cool food items between 45F to 35F.  These are commercial units that are a far cry from your household refrigerator.  They are made out of much heavier gauge sheet metal with heavy duty doors and larger refrigeration units to pull down warm product faster.  
The one we are starting out with is a Traulsen brand 2 door unit.  This unit has a problem.
The video below gives the problem symptoms.  You figure out what is the problem.

This video gives the answer to the previous video.

This cooler has a refrigerant leak.  let's see where the leak is.

The leak we found here is very common on units that hold salads.  Salads are acidic and will corrode the evaporator.  Note the coil is coated with a product designed to limit the corrosion.  Obviously, the corrosion has gotten thru.  Usually repairs to the evaporator in this condition will not be successful as another leak will probably pop up in the near future.  
Charging the medium temp box
The video below covers how the medium temp should be charged.  This unit is controlled by a TXV.  This video will not be available until 9-22-14