There is much talk and discussion in certain forums about how to determine the correct refrigerant charge level for a capillary tube refrigeration system, but there is only one, simple method that will result in the perfect charge in a Frigoboat system; the frost-line method. Pressures and current draw can be monitored to confirm that these are within expected limits, but there is no better way to guage the refrigerant level than with the frost-line method.
Frigoboat R134a charge guidelines
GeneralThe following is intended to be a guide for a boat operator with average mechanical skills. It will describe what symptoms to look for in a correctly charged Frigoboat system so that an evaluation can be made as to whether service is required. No refrigerant gauges are necessary for this evaluation, and their use is required only for major repairs and for evacuating the system.
Warning!Never use, or allow a technician to use, anything other than pure refrigerant R134a in a Frigoboat system. Cans of refrigerant R134a with additives must never be used, nor must stand-alone additives be introduced into the system. These additives include but are not limited to: leak detecting fluid, leak stopper, dye, extra oil, conditioner, etc. Serious damage can result from the use of such products, which are designed for use only in auto air conditioning systems.