Thermo Fisher Scientific ULT Freezers
Backup System (Optional) | 17
washer. Ensure the correct nut fitting is supplied over
the nipple (US or European).
•
Add 2 wraps of Teflon tape clockwise to the 1/4"
NPT fitting (on the nipple) when viewed from the
threads. Tighten the NPT fittings approximately
2 turns from finger tight (approximately 720°).
Note :
The top of the nipple has a hex configuration,
allowing for use of a wrench when the nut is pulled
down.
•
Add washer to nipple inside of nut (unless CO
2
supply has a built in washer).
Note :
Small raised area of washer fits into groove of
nipple. The washer will feel snug when trying to shift
side-to-side on nipple. The washers are designed for
a limited number of attachments/disconnections
from the supply and may wear over time. If washer
appears worn and causes CO
2
leakage, replace
washer (Part Number 45705H03).
•
Wrench tighten the supply nut to the supply.
•
For LN
2
: Attach the fitting to the supply and wrench
tighten.
Note:
Do not twist, torque, or subject the flexible hose to
sharp bends. Doing so may shorten the life of the hose.
Start Up
When the unit is started, it will recognize if a backup system is
installed.
set the backup system type and setpoint.
2. It is recommended to test backup system operation prior
to sample storage.
Test BUS Operation
After the freezer has stabilized and both batteries are fully
charged, the BUS can be tested to verify proper operation.
1. Disconnect the AC power to the freezer by turning the
power switch off.
2. As the freezer warms up, verify the BUS injects at the
desired temperature. Displayed temperature may vary by
a few degrees from injection temperature due to the
differences in probe locations.
Note:
On a monthly basis, it is recommended to test your
backup system, check the supply tank system levels, and
check the backup battery voltage.
Operation
The backup system can run for a minimum of 24 hours on
battery power.
On average, a backup system in operation uses 8 to 10 lbs.
per hour of CO
2
(3.6 to 4.5 L/hr) or LN
2
(4.5 to 5.6 L/hr) at an
ambient temperature of 25°C.
This rate will vary depending on set point, load, ambient
temperature and freezer size.
