Appendix 1: Refrigerant And Oil Charge - Toshiba QuietCo2OL Notice D'instructions

APPENDIX 1 : REFRIGERANT AND OIL CHARGE
This appendix gives the instructions for charging the unit with R744 and additional oil.
The following assumptions have been made in order to calculate both charges:
- 90% filling factor for gascooler in partload.
- Min/Max level in receiver: 10% / 80%.
- Liquid line and suction line diameter following the specifications page 15.
- 20% filling factor for the evaporator.
Here's an example of how to determine the required charges:
- In this case, an MT67 unit has to be installed with a 7dm
following diagrams gives the corresponding R744 and oil charge :
Evaporator volume
- Start on the crossing point of the unit (MT67) and the length of the pipe (20 meters),
- Draw a horizontal line from this point which crosses the evaporator volume line,
- Draw a vertical line from the crossing point of both lines and read both CO
bottom) and additional oil charge (at the top).
- In this particular example, the R744 charge equals 7.2 kg and an additional oil charge of 250
mL is required because the refrigerant charge is over 6.5kg.
Remark : Given the uncertainties on site concerning the real volume of the equipment, we recommend using
the complete volume of any opened oil container delivered in addition with the unit.
The installer also has to consider the zone of this crossing point for charging restrictions:
- Green zone : No restrictions
- Yellow zone :
overfilled and cause compressor damage by liquid floodback. In case of service on the liquid line,
it is important to fully empty the circuit and make the complete refrigerant fill after servicing the
unit. The full load cannot be stored in the unit
- Red zone : Not
The diagrams for the different models are shown in the next pages.
These diagrams are indicative. It's under the responsibility of the installer to ensure the proper operation of the unit
and to adjust the refrigerant charge, especially ensuring that the consumers operate at a proper superheat.
Warning : Do not pump down the liquid line into the unit, or the receiver could be
allowed.
3
evaporator and a 20m pipe. The
38
Pipe length
charge (at the
2