Extech Instruments 470 - Manual (Page 3)

V5.0 5/04 3
OVERVOLTAGE CATEGORY III
This meter meets the IEC 610-1-95 standard for OVERVOLTAGE
CATEGORY III. Cat 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:
Input Protection Limits
Function Maximum Input
V DC or V AC 1000VDC/750AC, 200Vrms on
400mV range
mA AC/DC 500mA 250V fast acting fuse
A AC/DC 20A 250V fast acting fuse(30
seconds max every 15 minutes)
Frequency, Resistance,
Capacitance, Duty Cycle,
Diode Test, Continuity 250Vrms for 15sec max
Temperature 60V DC/24V AC
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.