User Manual Owner manual

DUAL DISPLAY DIGITAL MULTIMETER
USER MANUAL
25
7. MAINTENANCE
The following instructions are executed by qualified personnel only.
To avoid electrical shock, do not perform any servicing other than the
operating instructions unless you are qualified to do so.
7-1. Line fuse replacement
If the fuse blows, the DMM would not work. Try to determine and
correct the cause of the blown fuse, then replace the fuse with correct
rating and type shown as below:
FUSE RATING AND TYPE
100/120V T0.16A 250V
220/230V T0.08A 250V
F101 on PCB T0.5A 250V
7-2. Current fuse replacement
The current fuse protects the 500μA~ 2A range from an input
current greater 2A.To replace the current fuse, perform the following
steps:
1). Turn off the power, disconnect the power line and remove the test
leads.
2). Place the end of a flat blade screwdriver into the slot of the fuse
holder on the front panel. Push and carefully rotate the fuse carrier
turn counterclockwise till remove the fuse and the fuse carrier off
the front panel.
3). Remove the defective fuse and replace the correct fuse (T2A 250V,
1.5kA breaking capacity ).
Remark: There is a F20A fuse built inside the case located on F301,
if any damage occurred on this fuse, please return to the
manufacturer for repair.
DUAL DISPLAY DIGITAL MULTIMETER
USER MANUAL
26
7-3. Line voltage conversion
The primary winding of the power transformer is tapped to permit
operation from 100/120V, or 220/230V AC 50/60Hz line voltage.
Conversion from one line voltage to another is done by changing the
line voltage selector switch as shown in Figure 4-2. The rear panel
identifies the line voltage to which the unit was factory set. To convert
to a different line voltage, perform the following procedure:
1). Make sure the power cord is unplugged.
2). Adjust the line voltage selector switch to the desired line voltage
position.
3). A change in line voltage may also require a corresponding change
of fuse value. Install the correct fuse value as listed on rear panel.
7-4. Cleaning
To keep the instrument clean, wipe the case with a damp cloth and
detergent. Do not use abrasives or solvents.