Toshiba QuietCo2OL Notice D'instructions page 57

GENERAL STARTUP INSTRUCTIONS
Method of Charging
– Use Manifold Gauges and charging hoses for CO
– Use only refrigeration quality R744.
– When charging the refrigerant fix the flexible to the frame to avoid any risks
– Use a refrigerant scale to measure correct quantity charged into the system from
the R744 cylinders.
– Oil Charging must be done through the liquid service line during vacuum operation
– Close the vacuum pump and break the vacuum with vapor R744 until 7-10Bar to
avoid dry ice formation. Dry ice may block hoses and pipes and charging will be
impossible. Charge vapor in both suction and liquid line.
– Control that the expansion valve at the evaporator(s) is active. Control both
electronic pressure transmitters and manifold Gauges for correct pressure
readings.
– As vapor is drawn from the R744 cylinders, pressure and temperature inside the
cylinder will decrease. Frost at the bottom exterior of the cylinder is an evidence
that liquid R744 has evaporated inside. The reduction in pressure also causes a
slower flow rate of vapor into the system. Once the flow from the cylinder has
slowed to a low level, the cold cylinder should be disconnected and warmed up at
ambient temperature. After the cylinder has been warmed up, the residual R744
can be charged. In the meantime, another charging bottle can be connected to the
system to continue the charging process.
– Do not charge liquid on compressor suction line. Only Gas.
– Charge the machine only in vapor phase. The charge should be done on the
suction line. Never charge the machine with liquid. Premature wear risk
when restarting.
– Overfilling the system may cause malfunction and compressor damage.
– Sight Glass on the liquid line does not indicate correct R744 level if 100% full.
Control superheat management is inside min-max superheat settings.
level in the sight glass is ok.
– The refrigerant charge should be done by monitoring the superheat at the
consumers. A stable superheat around the setpoint will show that the charge is
adapted to the installation.
– Simulate transcritical conditions when charging in low ambient conditions by
blocking the air flow into the condenser/gas cooler in order to control correct
charging level.
– Run the unite and simulate thermostat cut off, defrosting cycle or manual pump
down in order to control correct operation and R744 charge.
– In case of leakage detection and repair: empty the system completely and
refill according to the first filling charge.
only.
2
5
¾ of filling