Thermo 6464K, Instruction Manual

Page: 6 / 24

OM6464K Rev. 4 11 January 2004
Page 6 of 24
WARNING WARNING
!
International Electrotechnical Commission standard
1010 part 2-20 limits the permitted movement of a
laboratory centrifuge to 12” (300 mm) in the unlikely
event of a disruption. Laboratory management
procedures should require that no person or any
hazardous materials enter within this boundary while
the centrifuge operates.
2.3 Verify Power Configuration
1. Verify that the correct power cord and connector is
provided for your installation.
The unit requires a grounded power supply (3-outlet).
If your facility does not have grounded power outlets,
arrange for proper grounding. The power cord plugs in
on the left side of the unit.
WARNING
WARNING
!
ELECTRICAL HAZARD!
Do not remove the grounding pin from the
centrifuge power cord. Do not use the bare
wired power cord to attach a power plug that
does not have a grounding pin.
The power cord provided with the unit is
correctly rated for the highest current demand.
This power cord should not be interchanged
with cords from equipment with lower current
demand. Exchange of power cords between
equipment may create a fire hazard.
2. For best results, the refrigerated centrifuge should be
used on a dedicated line. Variations in line voltage or
frequency affect the unit’s speed and other
characteristics.
NOTE:
Less than nominal line voltage may prevent the
centrifuge from reaching maximum published
specifications of speed and/or temperature. Power line
voltage, at some locations, may sag when the
refrigeration system turns on.
2.4 Moving the Unit
Suction cups at the bottom of the unit keep it anchored to
the work surface. Keeping the unit stationary is a safety
feature.
To move the unit to a new location:
WARNING
WARNING
!
The unit can weigh up to 222 lb. (101 kg).
Use caution when moving to avoid any injury.
1. Check that the new site meets the criteria in Section
2.2 before moving the unit.
2. Position a flat object, such as a tongue depressor, near
a suction cup at the bottom of the unit.
3. Lift up an edge of the cup, and insert the flat object far
enough to break the vacuum suction seal.
4. When all four suction cups are disengaged, lift the unit
from the work surface.
5. When the unit is in its new location, ensure that the
suction cups adhere correctly to the work surface
3. Operation
3.1 Rotor and Accessories
A balanced load is essential for all centrifuges. An
unbalanced load produces vibration, and can damage the
unit. ALWAYS balance containers on opposite sides of the
rotor.
NOTE : A 2-gram load imbalance, at a speed of 4600
RPM, imparts force equivalent to 20 pounds (9.1 kg) at
rest. Always ensure that the rotor is loaded
symmetrically, with a full complement of accessories,
and a full (or paired) set of tubes. Tube adapters should
also be installed symmetrically.
Balance load within 1 gram
The rotors are dynamically balanced at the factory. The
manufacturer matches removable parts (trunnion rings,
shields, buckets, and carriers) to within 1 gram, and
stamps the weight on each piece. Check these markings,
whenever you interchange parts, to ensure that opposite
parts are matched. Ensure that the total weight of samples
and removable parts, loaded in opposing positions, are
equal in weight, to within 1 gram. The position numbers,
present on many rotors and adapters, identify opposing
tube positions.
Opposing containers must be alike in shape, thickness, and
distribution of glass or plastic. This is especially important
for large containers.
NOTE:
Swinging Bucket Rotors:
Tubes loaded into swinging bucket rotors must be
symmetric, around the axis of rotation. Verify this by
rotating the entire rotor 180° by hand. The loads
should be in the same apparent positions (not mirror
images). In addition, the loads within each bucket
must, also, be symmetric around the bucket’s pivot
axis. Verify this by ensuring that each bucket is loaded
so that it does not tilt from the vertical, when the rotor
is at rest. Maintaining balance within each bucket
ensures that the bucket and the tubes swing out to
horizontal, when the rotor reaches operating speed,
applying centrifugal force toward the bottom of the
tubes. Failure to achieve full swing-out causes vibration
and premature wear of the rotor and the motor.
Samples of like (similar) specific gravities may be
processed in the same run, provided that the samples of
the same type are balanced around the rotor, as though
they were the only pairs in the rotor.
CAUTION
!
Do not exceed maximum rated speed for each rotor/
accessory combination. Maximum rated speeds can be
found in Section 4.2 - Speed And Force Tables.
Rotor Balance
Load tubes in the following manner: