UNISource Corporation DM-1150B Operation Manual page 20

7. MAINTENACE
The meter is a precise and intelligent instrument. It has been accurately calibrated in the factory before shipment.
Readjustment is recommended only if repairs have been made in a circuit affecting adjustment accuracy or if you
have a reason to believe the unit is out of adjustment.
The following instructions are for use by qualified personnel only. To avoid electrical shock, do not perform any
servicing other than contained in the operating instructions unless you are qualified to do so.
Do not verify the circuit to avoid damaging. Power fuse: 200mA/250V (located in input power socket); Fuse for
measuring current: 800mA/250V (located in the current input terminal), 13A/250V (located the main circuit). The
fuse must be replaced by qualified personnel.
NOTE:
Do not connect the voltage higher than DC1000V or AC 1000V rms.

Do not measure voltage at the Ω range.

When replacing fuse, please take away the test leads from the measuring point and power off at first.

Keep the instrument away from water, dust and shock.

Do not operate the meter in high temperature or strong magnetic place.

Do not use the abrasives or solvents to clean the meter.

7.1 Fuse replacement
NOTE: Please select fuse of the same specification to replace it.
Power fuse: 200mA/250V (located in input power socket); Fuse for measuring current: 800mA/250V (located in
the current input terminal), 13A/250V (located the main circuit).
1. Test fuse replacement:
 Press the function key to Ω range
 Connect a test lead to "VΩHz" terminal, use the pen tip to touch the "mA" or "20A" terminal to test the
resistance of the fuse
 If the tested fuse resistance is below 5Ω, it means the fuse is good.
 If the tested result is "OL" (over load), the fuse needed to be replaced.
 If the fuse is tested as good but the multimeter cannot carry measurement, please send the multimeter for
repair.
2. Fuse replacement
Disconnect the multimeter from AC power source, and take off all test leads.
2A fuse replacement
Press "mA" input jack by finger; take out the fuse jack after turning 90°angle anti-clockwise
Take off the fuse, and replace an equivalent then turn on the fuse jack.
After press the fuse into the fuse jack, turn 90°angle by an inverse hour direction.
13A fuse replacement (must be replaced by qualified personal.)
Screw off the four screws on the button shell by a screwdriver, take off the upper shell.
Take off the fuse, and replace an equivalent then turn on the fuse jack.
Take on the shell, .Screw on the four screws on the button shell by a screwdriver.
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