Lakeshore 336, User Manual

Page: 167 / 192

8.6 Fuse Replacement 155
|
www.lakeshore.com
8.6 Fuse
Replacement Use this procedure to remove and replace a line fuse.
To avoid potentially lethal shocks, turn off controller and disconnect it from AC power
before performing these procedures.
For continued protection against fire hazard, replace only with the same fuse type and
rating specified for the line voltage selected.
Test fuse with an ohmmeter. Do not rely on visual inspection of fuse.
1. Locate the line input assembly on the instrument rear panel. See Figure 8-2.
2. Turn the power switch Off (O).
3. Remove the instrument power cord.
4. With a small screwdriver, release the drawer holding the line voltage selector
and fuse.
5. Remove existing fuse(s). Replace with proper Slow-Blow (time-delay) fuse ratings
as follows:
6. Re-assemble the line input assembly in reverse order.
7. Verify voltage indicator in the line input assembly window.
8. Connect the instrument power cord.
9. Turn the power switch On (l).
8.7 Factory Reset
Menu It is sometimes necessary to reset instrument parameter values or clear the contents
of curve memory. Both are stored in nonvolatile memory called NOVRAM, but they
can be cleared individually. Instrument calibration is not affected except for Room
Temperature Calibration, which should be recalibrated after parameters are set to
default values or any time the thermocouple curve is changed.
FIGURE 8-2 Power fuse access
100/120 V 4 A T 250 V 5 × 20 mm
220/240 V 4 A T 250 V 5 × 20 mm