Binder ULTRA.Guard UF V 500, Руководство по эксплуатации, Страница: 79 / 117

UF V (E3) 09/2018 Page 79/116
Control and temperature measurement of the chamber controller are used for the CO
2
emergency cool-
ing, therefore this option cannot be used for ultra-low temperature freezers from other manufacturers
The optional CO
2
emergency cooling is intended only for the use with a BINDER ultra-low
temperature freezer UF V.
The CO
2
emergency cooling offers additional refrigeration when the inner chamber temperature increased
up to the pre-set emergency cooling temperature. This may become necessary, following introduction of a
heat load, in case of a power failure or failure of the cooling system.
Principle: CO
2
is taken from the gas bottle in liquid form and introduced into the freezer UF V when re-
quired. There the gas expands and cools off intensely, forming a mixture of CO
2
gas and CO
2
snow. The
CO
2
snow provides the required cooling capacity through the transition into the gaseous state.
The emergency cooling system is integrated into the safety chain of the chamber. In case of power failure,
rechargeable batteries supply the CO
2
emergency cooling power supply, during normal operation power is
supplied by a power supply unit 24V DC. The rechargeable battery is designed for an interruption of the
external power supply of 72 hours maximum. Therefore, if pressurized CO
2
cylinders are available in suf-
ficient quantity, functioning of the CO
2
emergency cooling should last through a week-end.
You can set the CO
2
emergency cooling system between -40 °C / -40 °F and -70 °C / - 94 °F . In order to
ensure an emergency cooling time as long as possible with a given CO
2
stock, select the highest possible
emergency cooling temperature.
The optional CO
2
emergency cooling system is also available as a retrofit kit. Please contact BINDER
Service.
The upper 28 mm access port (6a) on the chamber rear serves to connect the CO
2
emergency
cooling.
21.1 Connecting and exchanging the pressurized CO
2
cylinder
The CO
2
emergency cooling system works exclusively with liquid CO
2
. Use CO
2
dip tube cylin-
ders. The dip tube inside enables almost complete liquid withdrawal. CO
2
dip tube cylinders
must stand upright during withdrawal.
Note regarding the installation site of the gas cylinder:
The cooling power decreases with increasing temperature of the liquid CO
2
. Do not install the gas cylinder
in the exhaust airflow of the UF V.
The supplied gas hose (17) is already connected with the CO
2
emergency cooling system. The user shall
not remove this connection. When replacing the gas hose is required, please contact BINDER Service. To
connect the pressurized CO
2
cylinder, connect the free end of the gas hose to the gas cylinder (wrench
size A/F 30 mm / 1.2 in ). Then open the valve of the gas cylinder.
Before changing the gas cylinder, first close the valve of the empty gas cylinder. Perform a test run of the
CO
2
emergency cooling to reduce the CO
2
pressure in the emergency cooling system. Only then unscrew
the gas hose.
After connecting the gas cylinder, check the hose connection with a soap solution for gas
leaks. The hose connection must be tight