What is the correct method to check subcool. I take it for a correctly charged system subcool would be in the region 15K. Also how can one tell when an expansion valve is "hunting". I know these questions seem pretty elementary but subcool, superheat are two of the major aspects which control the stability and balance of a system, and also show up if the system is not designed correctly, ie: mismatch of components.
If only these aspects were emphasised enough, Im not sure if there is a simple foolproof guide which us "techs" can understand and carry out each and every time we install. As Marc says, the designers are putting together components whilst seated in their offices, its the techs in the field who have to do the "fixes" Often they dont are not able to, they have too much confidence in the design engineer. Before the installers and the design engineers "polarise" the techs need to be able to assert their knowledge of system operation, backed up with readings and data and if necessary "challenge" the wisdom of the designer.
Am I right here?