Extech Instruments EX470A User Manual page 4

OVERVOLTAGE CATEGORY III
This meter meets the IEC 61010-1 (2010) 3
III meters are protected against overvoltage transients in fixed installation at the distribution level.
Examples include switches in the fixed installation and some equipment for industrial use with
permanent connection to the fixed installation.
SAFETY INSTRUCTIONS
This meter has been designed for safe use, but must be operated with caution. The rules listed below
must be carefully followed for safe operation.
1. NEVER apply voltage or current to the meter that exceeds the specified maximum:
Function
V DC or V AC
mA AC/DC
A AC/DC
Frequency, Resistance, Capacitance,
Duty Cycle, Diode Test, Continuity
Temperature
2. USE EXTREME CAUTION when working with high voltages.
3. DO NOT measure voltage if the voltage on the "COM" input jack exceeds 600V above earth
ground.
4. NEVER connect the meter leads across a voltage source while the function switch is in the
current, resistance, or diode mode. Doing so can damage the meter.
5. ALWAYS discharge filter capacitors in power supplies and disconnect the power when making
resistance or diode tests.
6. ALWAYS turn off the power and disconnect the test leads before opening the covers to replace
the fuse or batteries.
7. NEVER operate the meter unless the back cover and the battery and fuse covers are in place
and fastened securely.
8. NEVER look directly at the laser light source or aim the pointer at an eye.
rd
edition standard for OVERVOLTAGE CATEGORY III. Cat
Input Protection Limits
600V, 200Vrms on 400mV range
500mA 600V fast acting fuse
10A 600V fast acting fuse (30 seconds max every 15
minutes)
250Vrms for 15sec max
60V DC/24V AC
4
Maximum Input
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