6875 Freezer/Mill
Page 9 of 42
SPEX® SamplePrep LLC
DEC 2015
4.1 Electrical Connection
Plug the electrical cord into the inlet on the back of the Freezer/Mill cabinet, and then into a
standard 3-prong grounded electrical outlet. A fused 20-amp circuit is recommended for the
115V/60 HZ version. The 230V/50HZ, 6875 Freezer/Mill is supplied with a standard European
2-prong plug with cord. For the 230V/50HZ version, make sure the cord and plug conform to
local electrical codes.
The fuses are next to the electrical cord inlet in the Fuse Holder. To replace a fuse, first remove
the electrical cord from the inlet. Use a small screwdriver to pry open the fuse panel. There are
two individual fuse holders, each with a protruding tab. Push the tab sideways to pop out the
fuse holder allowing the holder to be removed with the fingers.
Never use pliers or force to
remove a fuse holder.
Both fuses must be replaced. (Section 10.1)
4.2 Power Switch and Controller
Electric power to the Freezer/Mill is controlled by a rocker switch on the inlet module. It is
marked with two numerical symbols (0 for OFF and l for ON). Press the “l” side of the switch to
turn the power ON, or press the “0” side of the switch to turn the power OFF. When power to
the mill is turned ON, the controller display will light up.
The controller screen is a touchscreen that can be activated by a fingertip or stylus. Data is
transferred to other computer devices via USB Port, located in back of the controller. The 6875
Freezer/Mill has one grinding chamber, which is a programmed on the Control Panel screen
(Section 5.2). The programmable parameters include Cycles (number of grinding periods),
Precool Time (initial chilling of sample), Run Time (grinding period), Cool Time (time between
grinding periods), and Rate (speed of the impactor in cycles per second). The Control Panel also
displays a warning if the lid is not fully closed, or if there is not enough liquid nitrogen in the tub.
The viewing angle of the controller on the 6875 Freezer/Mill can be adjusted to minimize glare.
To adjust the viewing angle, simply grasp the back of the controller box and gently pull it forward
until the desired angle is reached, as shown in Figure 3. If it is necessary to send the unit back to
SPEX SamplePrep for service, be sure to return the controller to its horizontal position before
packing the unit for shipping.