Hello! Let me preface by saying I'm no refrigeration tech but I do have my Universal AC certification. I understand the basics of refrigeration only. I may be making my problem more complicated than it needs to be.
I have an aquarium chiller that has a custom made heat exchanger. The company that made the unit has gone out of business. There is no documentation. The main chassis and compressor are still made. See the specs below:
DT Code 19A00
Max Evap Temp = 45 degrees F
It's single capillary tube metering.
The model number translates to: M series, R-134a, Air-Cooled, High Temp, Revision 0, 1/4 HP, 115 volt, 1 phase, 60 Hz, no valves
The compressor model number has changed, the specs haven't. I have a new compressor in the box.
The problem is that this unit was designed to be an air to air unit versus and air to water unit. The custom exchanger is an 8" long, 3" PVC pipe shell with a 3/8" diameter titanium coil of some sort inside. Length and configuration are not known. 575 gallons per hour of 1.027 salinity sea water flows though 1" connections. In the past, there was a 1 degree F drop across the exchanger (at 575 gph).
The Copeland spec sheets have no information regarding minimum system charge to keep the compressor cooled. Any kind of exchanger should be "add X amount of charge per foot of tubing". I have spec sheets for both the air M2FH and water M2WH systems. Both say:
BTU Capacity at 60 Hz with 5 degree F subcooling.
HT Models are rated at 65 degree F return gas temperature.
The system was working fine per the customer with the exception of the compressor making a huge rattly noise on shut down. It was very wobbly like a spring support broke. I weighed the recovery cylinder before and after the evac process and found only 5.8 oz of refrigerant had been removed. It doesn't sound like enough but I have no frame of reference.
Should I ignore any presuppositions I have and charge based upon the spec sheets even though there is a non-standard heat exchanger installed? My concern is that there may not be enough charge to properly carry oil through the system. Temperature shouldn't be any problem. Then whatever comes out the chilled side "is what it is" right?
I will be adding service valves to the system. Would it be OK to add a small filter drier on the compressor outlet? Does someone have an actual working phone number for Emerson/Copeland Tech Support? I registered for the Emerson site but it pukes when I try to log in.