Extech MA620 Operating Manual

User's Guide

600Amp AC True RMS Clamp Meter

Model MA620

Introduction

Congratulations on your purchase of this Extech MA640 True RMS Clamp Meter. This meter
measures AC Current, AC/DC Voltage, Resistance, Capacitance, Frequency, Diode Test,
Duty Cycle and Continuity. Special features include Thermocouple Temperature and Non­Contact Voltage detection. The double molded case is designed for heavy duty use. This
meter is shipped fully tested and calibrated and, with proper use, will provide years of reliable
service.

Safety

International Safety Symbols

This symbol, adjacent to another symbol or terminal, indicates the user
must refer to the manual for further information.

This symbol, adjacent to a terminal, indicates that, under normal use,
hazardous voltages may be present

Double insulation

WARNING

CAUTION

PER IEC1010 OVERVOLTAGE INSTALLATION CATEGORY

OVERVOLTAGE CATEGORY I

Equipment of OVERVOLTAGE CATEGORY I is equipment for connection to circuits in
which measures are taken to limit the transient overvoltages to an appropriate low level.

Note – Examples include protected electronic circuits.

OVERVOLTAGE CATEGORY II

Equipment of OVERVOLTAGE CATEGORY II is energy-consuming equipment to be
supplied from the fixed installation.

Note – Examples include household, office, and laboratory appliances.

OVERVOLTAGE CATEGORY III

Equipment of OVERVOLTAGE CATEGORY III is equipment in fixed installations.
Note – Examples include switches in the fixed installation and some equipment for industrial
use with permanent connection to the fixed installation.

OVERVOLTAGE CATEGORY IV

Equipment of OVERVOLTAGE CATEGORY IV is for use at the origin of the installation.
Note – Examples include electricity meters and primary over-current protection equipment

This WARNING symbol indicates a potentially hazardous situation, which
if not avoided, could result in death or serious injury.

This CAUTION symbol indicates a potentially hazardous situation, which
if not avoided, may result damage to the product.

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SAFETY NOTES

• Do not exceed the maximum allowable input range of any function.

• Do not apply voltage to meter when resistance function is selected.

• Set the function switch OFF when the meter is not in use.

• Remove the battery if meter is to be stored for longer than 60 days.

WARNINGS

• Set function switch to the appropriate position before measuring.

• When measuring volts do not switch to current/resistance modes.

• Do not measure current on a circuit whose voltage exceeds 600V.

• When changing ranges always disconnect the test leads from the circuit under test.

CAUTIONS

• Improper use of this meter can cause damage, shock, injury or death. Read and
understand this user manual before operating the meter.

• Always remove the test leads before replacing the battery or fuses.

• Inspect the condition of the test leads and the meter itself for any damage before

operating the meter. Repair or replace any damage before use.

• Use great care when making measurements if the voltages are greater than 25VAC
rms or 35VDC. These voltages are considered a shock hazard.

• Always discharge capacitors and remove power from the device under test before
performing Diode, Resistance or Continuity tests.

• Voltage checks on electrical outlets can be difficult and misleading because of the
uncertainty of connection to the recessed electrical contacts. Other means should be
used to ensure that the terminals are not "live".

• If the equipment is used in a manner not specified by the manufacturer, the protection
provided by the equipment may be impaired.

Function Maximum Input

A AC 600A DC/AC
V DC, V AC 600V DC/AC
Resistance, Capacitance, Frequency, Diode Test 250V DC/AC
Type K Temperature 30V DC, 24V AC

250V DC/AC

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MA620 V2.1 07/08

Description

Meter Description

1. Current clamp

2. Clamp opening trigger

3. Hx % Button

4. MODE Button

5. LCD Display

6. Common Input jack

7. NCV sensor

8. NCV LED indicator

9. HOLD/BACKLIGHT Button and FUNCTION switch

10. RANGE Button

11. MAX-MIN Button

12. RELATIVE Button

13. Battery compartment (rear)

14. Positive Input jack

Display icons Description

HOLD Data Hold
AUTO Autoranging
DC Direct Current
AC Alternating Current
MAX Max reading
MIN Min reading

Low battery

REL Relative
V Volts (Voltage)
Ω Ohms (Resistance)
A Amperes (Current)
F Farad (Capacitance)
Hz Hertz (Frequency)
% Duty Ratio

o

F and oC Fahrenheit and Celsius units (Temperature)

n, m, μ, M, k Unit of measure prefixes: nano, milli, micro, mega, and kilo

)

)

•

) Continuity test

Diode test

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