Digital Ground Resistance Tester Model 4500
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WARNING
• If the supply switch is set to 110V AC and the instrument is connected
to 220V AC, the battery charge indicator (see Figure 3) will turn on
for several seconds, but will then turn off. The fuse will blow. Do not
continue to run the instrument.
• If the supply switch is set to 220V AC position and the instrument is
connected to 110V AC, the indicator will not turn on. The instrument
will not recharge or operate.
NOTE:
For either situation, errors in completing connections will not
endanger the instrument.
5.2.7 Replacing the Supply Fuse
An internal fuse is used to protect the instrument against an improperly
selected supply voltage.
To replace this fuse:
• Remove the six hex screws from the bottom of the case (see Figure
22), and lift the chassis from the case housing.
• Replace the fuse (Figure 24) and reassemble the instrument.
5.2.8 Replacing the Safety Fuse
An internal fuse which provides protection for up to 500V AC is used to
protect the instrument against voltages into the test leads.
To replace this fuse:
• Remove the six hex screws from the bottom of the case (see Figure
22), and lift the chassis from the case housing.
• Turn the chassis over.
• Replace the fuse (Figure 25) and reassemble the instrument.
