Coolant Charge - Mitsubishi Electric MEGR Manual

4.4.8.2 Connection of the pipes and fittings of the cooling line
•
The junction is for strong brazing with silver-based alloy (an alloy with medium-high silver content and low melting temperature
is recommended).
•
Use appropriate equipment.
•
Before brazing, clean the pieces to remove oil, grease, oxides, scale and dirt.
•
Use an appropriate solvent to remove oxides that form at high temperature during heating and brazing.
OBLIGATION:
The oxide that forms inside the pipe during the brazing process is dissolved by the HFC fluids and
causes obstruction of the coolant filter. During the brazing process it is advisable to introduce nitrogen
into the piping. If this is not possible, after completing the brazing operation wash the piping using
solvents.
4.4.9

Coolant charge

OBLIGATION:
Coolant charging operations must be carried out by qualified personnel in compliance with the local
regulations in force.
Below are the details for ensuring that the "good practice" rules are followed during the refrigerant
charge.
When charging with refrigerant, follow the "good practice" rules below:
•
Empty the machine of the inert gas charge;
•
Connect the vacuum pump to the Schrader connections on the machine and apply a vacuum;
•
Open the remote condenser taps and any other taps on the cooling line;
•
Do not open the taps on the internal machine;
•
Create a vacuum slowly in the connection line and in the condenser up to an absolute pressure of 0.3 mbar;
•
Once the value of 0.3 mbar has been reached, stop the vacuum pump and wait 3 hours to check the tightness of the circuit. A
slight rise in pressure is normal and must not exceed 0.5 - 1 mbar;
•
If the vacuum is not reached, there are leaks in the circuit;
•
In the case of very extensive cooling lines or lines heavily polluted by humidity, it is necessary to break the vacuum by loading
the circuit with anhydrous nitrogen (without oxygen), then repeat the vacuum operation as described above;
•
Disconnect the pump;
•
Charge with refrigerant as indicated in the specific internal machine manual.
Values to be used for calculating the system coolant charge.
4.4.9.1 Refrigerant content of remote condensers
The remote condensers are supplied with a charge for tightness testing. The cooling gas must be charged.
The tables show the coolant charge to be integrated for the condenser only: the internal unit, the connection pipes and any
accessories are excluded.
MICROCHANNEL EXCHANGER
STANDARD MODEL
Charging the coolant
STANDARD MODEL
Charging the coolant
TUBE AND FIN EXCHANGER
STANDARD MODEL
Charging the coolant
STANDARD MODEL
Charging the coolant
Installation, use and maintenance manual
013
Kg 0.50
055
Kg 2.07
014
Kg 0.8
065
Kg 3.8
015 024
0.50 0.85
067 082
2.56 2.56
019 028
0.7 1.5
074 088
4.9 4.9
027 034
0.85 1.30
110 134
4.14 5.12
036 045
2.3 1.9
130 149
7.6 9.7
049
2.07
164
5.12
057
2.7
176
9.7
29