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Thermo Scientific Revco
9.4 Setting the Cabinet Temperature
To set the cabinet temperature, complete the following steps:
1. Press and hold the Control Setpoint pad.
2. The Control setpoint LED lights and the Cabinet
Temperature LED goes out.
3. Press and hold
to increase the temperature or
decrease the temperature. The digital display scrolls through
temperature settings.
4. Release both pads when the digital temperature display
window shows the correct setpoint value.
If no keys are pressed within ten seconds, the
Note:
temperature display reverts to the cabinet temperature.
9.5 Alarm Operation
9.5.1 Setting the Alarms
In RevcoValue
models, the warm and cold alarm setpoints
PLUS
are set automatically with a 10ºC bracket. For example, if the
operating setpoint is -75ºC, the warm and cold alarms will be -
65ºC and 85ºC respectively.
You can change the bracket value in Program Mode, as explained
in Section 8.7 on page 7.
9.5.2 Silencing the Alarms
In Revco Value
models, you can silence alarms by turning
PLUS
the key switch to the ON (middle) position.
10 Backup System (Optional)
When you purchase a built-in CO
system for the freezer, backup control is integrated into Program
Mode (described in Section 8.7 on page 7).
Always purchase the cylinders which are equipped with
Note:
siphon tubes for withdrawing liquid from the bottom of
the cylinder. CO
cylinders must be kept at room
2
temperature to function properly. LN
functional at any reasonable temperature.
10.1 CO
and LN
Precautions
2
2
The following are precautions for using liquid CO
backup systems.
WARNING!
If a CO
valve is knocked off, the cylinder becomes a deadly
and completely unguided missile. Transport the
cylinders in a handtruck or cart with secure chain ties
for the cylinder. After cylinders are connected to the
equipment, securely attach them with chains to a
solid, stationary object such as a building column.
WARNING!
CO
but are very cold and will burn unprotected skin.
Always wear protective eyewear and clothing when
changing cylinders or working on the piping systems
attached to an active source of liquid refrigerant.
Upright Freezers
PLUS
or LN
optional backup
2
2
bottles are
2
and LN
2
or LN
cylinder falls and a
2
2
and LN
liquids are non-poisonous
2
2
WARNING!
CO
oxygen in a confined space and can cause
asphyxiation. Do not store the cylinders in
subsurface or enclosed areas.
CAUTION!
to
sure that the injection solenoid is energized to allow all
the liquid to bleed off instead of being trapped in the
supply tubing. Failure to do this results in activation of
the pressure relief device, which could damage the
freezer and requires replacing if it is activated.
CAUTION!
installed built-in backup systems, the flow of liquid
CO
during operation of the backup system. For units
operated with free-standing, field installed type backup
system, the flow of liquid CO
discontinued upon door opening
provided with the free-standing package is installed on
the freezer.
10.2 Installation
Field installed systems are supplied with complete installation
and operating instructions. If your system is factory installed, the
freezer is shipped with a coiled length of tubing to connect the
freezer to the bottles:
3/8 in. OD copper tubing for connection to the CO
•
5/8 in. OD copper tubing covered with Armaflex' insulating
•
tubing for connection to the LN
Straighten the coiled tubing and connect one end to the labeled
connection on the freezer and the other end to the supply bottle or
building supply fitting.
10.3 Startup
To activate the backup system;
1. Follow the instructions in Section 8 to power on the freezer
and set temperature and alarm setpoints.
2. Enter program mode and check the BUS setpoint value,
following the instructions in Section 8.7 on page 7. Adjust
this value if necessary.
3. Wait until the cabinet temperature has pulled down to below
the BUS setpoint value. This is important, because if you
2
turn on the Battery Enable Switch (Step 4) while the cabinet
is still warm, you may drain the battery.
4. When the freezer cabinet temperature is below the BUS
setpoint, activate the backup system by turning on the Battery
Enable Switch:
Remove the panel near the lower left corner of the front of
–
the freezer.
Turn on the Battery Enable Switch. Both the power switch
–
and the battery switch must be on for the backup system to
operate.
Replace the panel.
–
5. Turn on the CO
Installation and Operation
The gases produced by evaporation of
or LN
are non-poisonous but displace the
2
2
When closing the cylinder valve, make
For models ordered with factory
or LN
will be discontinued if the door is opened
2
2
or LN
2
supply.
2
or LN
supply.
2
2
will be
2
if the switch
only
supply.
2
9
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