28
BACKUP COOLING KIT (OPTION)
WARNING
As with any equipment that uses CO
2
gas, there is a likelihood of oxygen depletion in the vicinity
of the equipment. It is important that you assess the work site to endure there is suitable and
sufficient ventilation. If restricted ventilation is suspected, then other methods of ensuring a safe
environment must be considered. These may include atmosphere monitoring and warning
devices.
The freezer is provided with an automatic liquid CO
2
injection device as a Backup cooling kit. This
freezer prevents the chamber temperature from going up by injecting the liquid CO
2
when the power
supply is disconnected (power failure, disconnection of power cord, breaker OFF) or in the case of failure
of freezer itself. The liquid CO
2
is injected with the activation of solenoid valve energized by battery
when the chamber temperature reaches the alarm temperature.
Following shows the procedure for setting the Backup cooling kit.
1.
Setting of liquid CO
2
cylinder
By using the joint and pipe enclosed with the
freezer, connect the liquid CO
2
cylinder to the joint
of the Backup cooling kit. For this setting, consult
with a qualified gas supplier or our sales agency.
2.
After setting the liquid CO
2
cylinder, operate the
freezer until the chamber temperature reaches the
required level.
3.
Set the warning indicator of the temperature
setting knob of the Backup cooling kit at the
temperature higher than -70
o
C. The Backup
cooling kit is operated continuously if the warning
indicator is set at the temperature lower than -70
o
C.
This means the liquid CO
2
is consumed very
quickly.
4.
Switch on the Backup cooling kit.
5.
Make sure that liquid CO
2
spouts into the chamber by pressing the back-up test switch.
Note:
• The liquid CO
2
cylinder loses its cooling capacity at speed when the ambient temperature is over 31
o
C.
Install the liquid CO
2
cylinder in the cool environment. And the duration of backup time per one liquid
CO
2
cylinder varies depending on the ambient temperature. Refer to “Installation of Backup cooling kit”
enclosed with the freezer for the available backup time.
• The liquid CO
2
cylinder should be a siphon type.
• Use the pipe encloses with the freezer for the setting. (The extension of the pipe is not permitted
because of cooling capacity.)
Rough scheme
Battery
Pipe
Liquid CO
2
gas cylinder
Solenoid valve
