pressure gauge and turn off the vacuum
pump.
Maintain pressure for 20 minutes and
make sure there is no leak.
INJECTING REFRIGERANT
STEP
PRECAUTION
Remove the vacuum pump from the
charging meter. Connect the refrigerant
cylinder to the charging meter with the
connection pipe as short as possible.
Unscrew refrigerant cylinder and put it
upside down on the electronic scale.
ATTENTION: The charging volume is
very small for the R290 refrigeration
system, so it’s necessary to precisely
control the charging volume within 2g.
The precision of the electronic scale shall
be 0.5g.
Prepare the connection pipe, pressure
gauge and accessories; empty the
charging pipe; and set the electronic
scale to zero.
The hose connecting the cylinder and
charging meter shall be tension-free to
minimize error of charging volume.
Slowly open the low pressure valve of the
pressure gauge. When the charging
volume reaches the rated volume
indicated on the nameplate, immediately
close the low pressure valve, and then
close the R290 refrigerant cylinder to stop
the charging.
NOTE: Keep charging pressure below
3Bar all the time to prevent fast charging.
Fast charging will lead to a charging error.
SEALING AND COMMISSIONING
STEP
PRECAUTION
Use a leak tester to check the machine
for any leaks.
After confirming there is no leak, use the
sealing pliers to clamp flat the process
10