6875 Freezer/Mill
Page 37 of 42
SPEX® SamplePrep LLC
DEC 2015
10.0 MAINTENANCE
The 6875 Freezer/Mill has been designed to provide trouble-free operation over a long period of
time. To assure proper performance it is very important to keep the unit clean. When the
Freezer/Mill is at room temperature, any spilled powders or liquids should be wiped up
immediately. The internal tub should be wiped clean with a damp cotton cloth after every use.
This should prevent the buildup of any powders, mold/mildew, or other residue over the life of
the unit. If any samples, powder materials, or liquids are spilled inside the unit during a sample
run, wait until Freezer/Mill is finished for the day, the liquid nitrogen has evaporated, and the mill
has warmed up to room temperature before attempting to clean it. Once the unit has attained
room temperature, wipe down the unit as indicated previously. After every period of use, the
mill will become wet with condensation due to the Freezer/Mill picking up moisture from air
when it is cold.
To maintain the exterior of the unit, first disconnect the Freezer/Mill from its electrical source.
Then lightly spray with a mild window cleaner or similar product and wipe unit down. If the 6875
Freezer/Mill requires service, please call SPEX SamplePrep Customer Service for assistance.
10.1 Changing the Fuses
If the Freezer/Mill will not operate when the start button is pressed, it is possible that one or
both of the fuses may have blown. To access the fuses, first remove the power cord from the
back of the Freezer/Mill. Then open the door on the fuse compartment by gently prying it open
at the top and flipping it down, as shown in Figure 21. Use a small screwdriver to gently pry the
red fuse holder out of the compartment, as shown below. Remove the fuses and check them
using a continuity tester. If either fuse is blown or defective, replace both with 3AG 5-amp, 250V
slow-blow fuses. Position the fuse holder such that the appropriate operating voltage appears on
top. Return the fuse holder to the fuse compartment and close the access door. Check the
window of the fuse compartment to make sure that it shows the appropriate voltage. If not, the
fuse holder is upside down and must be turned around before attempting to operate the
Freezer/Mill.
Figure 22
– Fuse Compartment