Omega HHM-MA640 User manual

HHM-MA640
600Amp AC/DC
True RMS Clamp Meter
e-mail: [email protected]
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User’s Guide
MADE IN CHINA

Servicing Nort America:
U.S.A.: Omega Engineering, Inc., One Omega Drive, P.O. Box 4047
ISO 9001 Certified Stamford, CT 06907-0047
Toll-Free: 1-800-826-6342 Tel: [phone]
FAX: [phone] e-mail: [email protected]
Canada: 976 Bergar
Laval (Quebec), H7L 5A1 Canada
Toll-Free: 1-800-826-6342 TEL: [phone]
FAX: [phone] e-mail: [email protected]
For immediate tec nical or application assistance:
U.S.A. and Canada: Sales Service: 1-800-826-6342/1-800-TC-O EGA®
Customer Service: 1-800-622-2378/1-800-622-BEST®
Engineering Service: 1-800-872-9436/1-800-USA-WHEN®
Mexic En Español: 001 [phone] FAX: [phone]
Latin America [email protected] e-mail: [email protected]
Servicing Europe:
Benelux: anaged by the United Kingdom Office
Toll-Free: 0800 099 3344 TEL: [phone]
FAX: [phone] e-mail: [email protected]
Czech Republic: Frystatska 184
733 01 Karviná, Czech Republic
Toll-Free: 0800-1-66342 TEL: [phone]
FAX: [phone] e-mail: [email protected]
France: anaged by the United Kingdom Office
Toll-Free: 0800 466 342 TEL: [phone]
FAX: [phone] e-mail: [email protected]
Germany/ Austria: Daimlerstrasse 26
D-75392 Deckenpfronn, Germany
Toll-Free: 0800 6397678 TEL: [phone]
FAX: [phone] e-mail: [email protected]
United Kingd m: O EGA Engineering Ltd.
ISO 9001 Certified One Omega Drive, River Bend Technology Centre, Northbank
Irlam, anchester 44 5BD United Kingdom
Toll-Free: 0800-488-488 TEL: [phone]
FAX: [phone] e-mail: [email protected]
OMEGAnet®Online Service Internet e-mail
mega.c m inf @ mega.c m
It is t e policy of OMEGA Engineering, Inc. to comply wit all worldwide safety and EMC/EMI
regulations t at apply. OMEGA is constantly pursuing certification of its products to t e European New
Approac Directives. OMEGA will add t e CE mark to every appropriate device upon certification.
T e information contained in t is document is believed to be correct, but OMEGA accepts no liability for any
errors it contains, and reserves t e rig t to alter specifications wit out notice.
WARNING: T ese products are not designed for use in, and s ould not be used for, uman applications.

MA640 V2.1 07/08
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Introduction
Congratulations on your purchase of this Extech MA640 True RMS Clamp Meter. This meter
measures AC/DC Current, AC/DC Voltage, Resistance, Capacitance, Frequency, Diode Test,
Duty Cycle and Continuity. Special features include Thermocouple Temperature and Non-
Contact 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
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.
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
WARNING
CAUTION

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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/DC, 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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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)
ΩOhms (Resistance)
A Amperes (Current)
F Farad (Capacitance)
Hz Hertz (Frequency)
% Duty Ratio
oF 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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Operation
NOTES: Read and understand all Warning and Caution statements in this operation
manual prior to using this meter. Set the function select switch to the OFF position when
the meter is not in use.
Non-Contact Voltage Detector
WARNING: Risk of Electrocution. Before use, always test the Voltage Detector on a
known live circuit to verify proper operation.
1. Rotate the Function switch to any measurement
position.
2. Place the detector probe tip on the conductor to be
tested.
3. If AC voltage is present, the NCV detector light will
turn on with a steady red light.
NOTE: The conductors in electrical cord sets are often
twisted. For best results, move the probe tip along
a length of the cord to assure placing the tip in close proximity to the live conductor.
NOTE: The detector is designed with high sensitivity. Static electricity or other sources of
energy may randomly trip the sensor. This is normal operation.
AC/DC Current Measurements
WARNING: Disconnect the test leads before making clamp measurements.
1. Rotate the Function switch to the
600A AC or DC position
2. Press the trigger to open jaw. Fully
enclose only one conductor.
3. Read the current value in the display.
4. If the value is less than 60A, rotate
the function switch to the 60A
position to improve resolution.
DCA Zero
The REL feature removes offset values
and improves accuracy for DC current
measurements. To perform a zero,
select ADC and, with no conductor in
the jaw, press and the REL button. The display will zero. The offset value is now stored
and removed from all measurements.

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AC/DC Voltage Measurements
CAUTION: Do not measure voltages if a motor on the circuit is being switched ON or
OFF. Large voltage surges may occur that can damage the meter.
1. Rotate the function switch to the V position.
2. Press the MODE button to select AC or DC Voltage.
3. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive Vjack.
4. Touch the black test probe tip to the negative side of the circuit.
Touch the red test probe tip to the positive side of the circuit.
5. Read the voltage value in the display.
Resistance Measurements
Note: Remove power from the device under test before making resistance measurements
1. Rotate the function switch to the Ω position.
2. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive Vjack.
3. Touch the black test probe tip to one side of the device.
Touch the red test probe tip to the other side of the device.
4. Read the resistance value in the display.
Continuity Test
1. Connect as described for resistance measurements.
2. Press the MODE button to select continuity •))).
3. Touch the test probe tips across the circuit or component under test.
4. If the resistance is < 60Ω, a tone will sound.

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Diode Test
1. Connect as described for resistance measurements
2. Press the MODE button to select diode test .
3. Touch the test probe tips to the diode or semiconductor junction under test. Note the
meter reading.
4. Reverse the test lead polarity by reversing the red and black leads. Note this reading.
5. The diode or junction can be evaluated as follows:
If one reading displays a value (typically 0.400V to 01.800V) and the other
reading displays OL, the diode is good.
If both readings display OL the device is open.
If both readings are very small or ‘0’, the device is shorted.
Capacitance Measurements
WARNING: To avoid electric shock, discharge the capacitor before measuring.
1. Rotate the function switch to the CAP capacitance position.
2. Press the MODE button to select nF capacitance test
3. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive jack.
4. Touch the black test probe tip to one side of the device.
Touch the red test probe tip to the other side of the device.
5. Read the capacitance value in the display.
Note: For very large values of capacitance measurement time can be
several seconds before the final reading stabilizes.

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Frequency and Duty Ratio Measurements
1. Rotate the function switch to the Hz Position.
2. Press the MODE button to select AC Voltage
3. Press the HZ % button to select HZ
4. Insert the black test lead banana plug into the negative COM jack.
Insert the red test lead banana plug into the positive Hz jack.
5. Touch the black test probe tip to one side of the device.
Touch the red test probe tip to the other side of the device.
6. Read the Frequency value on the display.
7. Press the HZ % button to select %
8. Read the Duty Ratio on the display.
Type K Temperature Measurements
1. Rotate the function switch to the Temp position.
2. Press the MODE button to select °F or °C.
3. Insert the Temperature Probe into the input jacks.
4. Place the temperature probe tip where needed.
5. Read the temperature on the display.
Note: In case of an open input or a temperature overrange, the meter will
display “OL”.

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Data Hold
To freeze the LCD reading, press the HOLD button. While data hold is active, the HOLD
icon appears on the LCD. Press the HOLD button again to return to normal operation.
MAX/MIN
1. Press the MAX/MIN button to activate the MAX/MIN recording mode. The display icon
"MAX" will appear. The meter will begins recording and displaying the maximum
value measured.
2. Press the MAX/MIN button and “MIN” will appear. The meter will display the minimum
value measured during the recording session.
3. To exit MAX/MIN mode press and hold the MAX/MIN button for 2 seconds.
RANGE
In the Voltage, Resistance, Frequency or Temperature function the meter automatically
selects the best range for the measurements being made. For measurement situations
requiring that a range be manually selected, perform the following:
1. Press the RANGE button. The “AUTO” display icon will turn off.
2. Press the RANGE key to step through the available ranges. Observe the decimal
point and units displayed until the preferred range is located.
3. To exit the Manual Ranging mode and return to Autoranging, press and hold the
RANGE key for 2 seconds.
LCD Backlight
The LCD is equipped with backlighting for easier viewing, especially in dimly lit areas.
Press and hold the HOLD/ button for 2 seconds to turn the backlight on. The backlight
will automatically turn off after 5 seconds.
Automatic Power OFF
In order to conserve battery life, the meter will automatically turn off after approximately 15
minutes of operation. The meter will beep shortly before the meter shuts off. If a button is
pressed, the APO timer will reset. If the meter is allowed to shut off, turn the function
switch to the OFF position and then to the function again to restart.
Low battery indication
When the icon appears in the display, the battery should be replaced. Refer to the
battery replacement procedure in the maintenance section.