Major tech MT775 User manual

MT775
AC TRUE RMS CLAMP METER
INSTRUCTION MANUAL
© 2004, MAJOR TECH (PTY) LTD. All rights reserved

1. Measuring Limits ........................... 1
2. Safety Warnings ............................ 2
3. Features ......................................... 4
4. Instrument Layout ......................... 5
5. Specifications ................................ 5
7. Data Hold Function ......................... 7
8. Peak Hold Function ........................ 7
9. LCD Backlight ................................. 7
9. AC Current Measurement .............. 8
10. DC Voltage Measurement .............. 9
11 AC Voltage Measurement ............. 10
12. Resistance Measurement ................ 11
13. Capacitance Measurement ........... 12
14. Frequency Measurement ............... 13
15. Temperature Measurement ........... 14
16. Diode Test ........................................ 15
17. Continuity Testing .......................... 16
18. Auto Power Off ............................... 17
19. Calibration ...................................... 17
20. Guarantee ....................................... 17
17. Battery Replacement .................... 18
18. Standard Accessories ................... 18
1. MEASURING LIMITS
AC Amperes : 0.1A to 1000A
DC Voltage : 0.1mV to 600V
AC Voltage : 0.1mV to 600V
Resistance : 0.1Ω to 40MΩ
Capacitance : 0.001 nF to 40mF
Frequency : 0.001 kHz to 4kHz
Temperature : -40 ºC to 1000 ºC
- 40 ºF to 1832 ºF
1
CONTENTS

2
2. SAFETY INFORMATION
This manual contains information that must be
followed for operating the meter safely and
maintaining the meter in a safe operating
condition. If the meter is not used in a manner
specified in this manual, the protection provided
by the meter may be impaired
The Model MT775 has been designed and
complies with IEC 61010-1 and EN 61010-1
Safety Requirements for Electronic Measuring
Apparatus.
WARNING
! Read through the operating instructions
throughly and understand the instructions
before operating the meter.
! Keep the manual at hand so as to enable
quick reference when necessary
! Ensure that the use of the meter is in its
intended applications and follow
measurement procedures described in this
manual.
! Follow all safety and operating instructions to
ensure maximum personal safety during the
use and operation of the meter.
! Failure to follow the above instructions may
cause injury, instrument damage and/or
damage to equipment under test.
!The symbol indicated on the meter means that
the user must refer to related parts in the
manual for safe operation of the meter. Be
sure to carefully read the instructions following
each symbol in this manual.
DANGER is reserved for conditions and
actions that are likely to cause serious or fatal
injury
WARNING is reserved for conditions and
actions that are likely to cause serious or fatal
injury
CAUTION is reserved for conditions and
actions that are likely to cause minor injury or
!
!
!
!

DANGER
! Never use the meter to measure voltages on a
circuit above the maximum allowable input
value on any function.
! Do not exceed the maximum allowable input
of any measurement range.
! Never touch exposed wiring, connections or
any live circuit when attempting to take
measurements.
! Do not attempt to make measurements in
flammable gaseous areas, fumes, vapor or
dust. The use of the instrument in these areas
may cause sparking , which can lead to an
explosion.
! Do not attempt to use the instrument if its
surface or your hand is wet
! Never open the battery compartment cover
when making measurements.
WARNING
! Always inspect the meter and test leads for
any signs of damage or abnormality before
use. If the meter or its accessories have any
structural defects such as broken test leads,
cracked cases, exposed metal parts or the
display is not reading, do not attempt to make
measurements.
! Do not turn the function switch whilst test
leads are connected to the meter.
! Do not install substitute parts or make
modifications to the meter. Return the meter
to your distributor for repair or re-calibration.
! Ensure the meter is switch off before opening
the battery cover when replacing the battery.
! Never replace a battery if the surface of the
meter is wet or moist.
3
!!
!

CAUTION
! Before making measurements ensure that the
function selector switch is set on the
appropriate range position.
! Always make sure that the plug of each test
lead is inserted fully into the appropriate
terminal of the meter.
! Ensure that the function selector switch is set
to the “OFF” position after use. When the
meter will not be in use for a long period of
time, place it in storage after removing the
battery.
! Do not expose the meter to direct sunlight,
extreme temperatures or moisture.
! Do not use abrasives or solvents on the meter.
To clean it use a damp cloth and mild
detergent only.
Qualified and trained service technicians should
only perform calibration and repair of the meter.
3. FEATURES
! True RMS measurement of AC Current and
AC Voltage
! Large 4000 count LCD display with bargraph
and a bright white LED backlight.
! Wide measuring range from 0.01A AC up to
1000A AC
! Measures AC and DC Voltage up to 600 volts
! Measures resistance from 0.01Ω up to 40MΩ.
! Capacitance measurements up to 40mF
! Temperature measurement from -40ºC to
+1000ºC and -40ºF to +1832ºF.
! Designed to the international safety standard
IEC61010 CAT lll 600V / CAT ll 1000V,
Pollution degree 2.
! Auto Power Off after approximately 20
minutes to conserve battery life.
! Continuity Buzzer and Diode Test
! Frequency measurement up to 4kHz
! Peak Hold to record the minimum and
maximum readings for current and voltage.
! Data Hold switch used to freeze reading on
display
4
!!

4. INSTRUMENT LAYOUT
Transformer
Jaws
Function
Switch
Jaw Trigger
Data Hold
Switch
Mode Switch
Display with
Bargraph
COM
Terminal
Volt, Resistance,
Frequency,
Temperature
Terminal
Backlight
Switch
Peak Hold
Selector Switch
for Volts and
Current
Clamp Size
Diode Test
Continuity Check
Low Battery Indication
Overrange Indication
Measurements Rate
Input Impedance
Display
AC Current
AC Voltage Bandwidth
Operating Temperature
Storage Temperature
Relative Humidity
Over Voltage
Battery
Auto Power Off
Dimensions
Weight
30mm Opening Approx
Test Current of 0.3mA typical;
Open circuit voltage 1.5V DC
Threshold <35Ω; Test current <1mA
“ “ is displayed
“OL” is displayed
2 per second, nominal
10MΩ (VDC and VAC)
4000 count LCD
50/60Hz (AAC)
50/60Hz (VAC)
-10ºC to 50ºC (-14ºF to 122ºF)
-30ºC to 60ºC (-14ºF to 140ºF)
Up to 85%
Category lll 600V
One PP3 “9V” Battery
Approx 20 minutes
229 x 80 x 49mm
303g
5. SPECIFICATIONS
5
-
+

5. SPECIFICATIONS
Range
AC Current
Measuring Range Resolution
40A
400A
1000A
0 ~ 40.00A
0 ~ 400.0A
0 ~ 1000A
0.01 A
0.1 A
1 A
Accuracy (% of Reading)
± (2.8% + 10 digits)
± (2.8% + 8 digits)
± (3.0% + 8 digits)
Range
DC Voltage
Measuring Range Resolution
400mV
4V
40V
400V
600V
0 ~ 400.0mV
0 ~ 4.000V
0 ~ 40.00V
0 ~ 400.0V
0 ~ 600V
0.1 mV
0.001 V
0.01 V
0.1 V
1 V
Accuracy (% of Reading)
± (0.8% + 2 digits)
± (1.5% + 2 digits)
± (2.0% + 2 digits)
Range
AC Voltage
Measuring Range Resolution
400mV
4V
40V
400V
600V
0 ~ 400.0mV
0 ~ 4.000V
0 ~ 40.00V
0 ~ 400.0V
0 ~ 600V
0.1 mV
0.001 V
0.01 V
0.1 V
1 V
Accuracy (% of Reading)
± (1.0% + 10 digits)
± (1.5% + 8 digits)
± (2.0% + 8 digits)
Range
Resistance
Measuring Range Resolution
400Ω
4kΩ
40kΩ
400kΩ
4MΩ
40MΩ
0 ~ 400.0Ω
0 ~ 4.000kΩ
0 ~ 40.00kΩ
0 ~ 400.0kΩ
0 ~ 4.000MΩ
0 ~ 40.00MΩ
0.1 Ω
1Ω
10 Ω
100 Ω
1 kΩ
10 kΩ
Accuracy (% of Reading)
± (1.0% + 4 digits)
± (1.5% + 2 digits)
± (2.5% + 5 digits)
± (3.5% + 10 digits)
Note: No Autoranging on 400mV AC Range
Range
Frequency
Measuring Range Resolution
4kHz 0 ~ 4.000kHz 0.001 kHz
Accuracy (% of Reading)
± (1.5% + 2 digits)
Sensitivity: 5Vrms min
Range
Temperature
Measuring Range Resolution
ºC
ºF
-40ºC ~ 1000ºC
-40.0ºF ~ 1832ºF
1 ºC
1 ºF
Accuracy (% of Reading)
± (2.5% + 3ºC)
± (2.5% + 5ºF)
6
Capacitance
Range Measuring Range Resolution
4nF
40nF
400nF
4µF
40µF
400µF
4mF
40mF
0 ~ 4.000nF
0 ~ 40.00nF
0 ~ 400.0nF
0 ~ 4.000µF
0 ~ 40.00µF
0 ~ 400.0µF
0 ~ 4.000mF
0 ~ 40.00mF
0.001 nF
0.01 nF
0.1 nF
0.001 µF
0.01 µF
0.1 µF
0.001mF
0.01mF
Accuracy (% of Reading)
± (5.0% + 30 digits)
± (5.0% + 20 digits)
± (3.0% + 5 digits)
± (4.0% + 10 digits)
± (4.5% + 10 digits)
± (5.0% + 10 digits)

6. DATA HOLD
This is a function used to freeze the reading on
the display, ideal for later viewing.
1. Press the button once. When the Hold is
activated, the meter beeps, freezes the
reading, and displays the “HOLD” indicator on
the LCD.
2. To deactivate the “HOLD” function, press
button once, the meter will beep and the meter
will start reading new measurements.
7. PEAK HOLD
This is a function used to record the maximum
and minimum readings on the display for the
voltage and current ranges.
1. Press the button once. This will record
the “PEAK” maximum, the meter beeps, and
displays the “P MAX” indicator on the LCD.
2. Press the button again. This will record
the “PEAK” minimum, the meter beeps, and
displays the “P MIN” indicator on the LCD.
3. To deactivate the “PEAK” function, press
button for 3 seconds,the meter will beep and
the meter will start reading new measurements.
8. LCD BACKLIGHT
The backlight is ideally used in dark or dimly lit
areas.
1. Press the button for 3 seconds, and the
bright white light will come on.
2. To turn off the backlight press the button
for 3 seconds.
Note: • The use of the backlight will reduce the
battery life considerably.
PEAK
PEAK
HOLD
HOLD
7

9. AC TRUE RMS CURRENT MEASUREMENT
WARNING: Ensure that the test leads are
disconnected from the meter before making
current measurements.
1. Set the function switch to or or
range position, and make sure that the current
under test does not exceed the upper limit of
the measuring range you have selected.
2. Press the trigger to open up the transformer
jaws and clamp around the single conductor
under test.
3. Read the display.
Note: • During current measurements keep the
transformer jaws fully closed, otherwise this
will affect the accuracy of the
measurement.
• When large currents the transformer
jaws may buzz. This is not a fault and
does not affect the accuracy of the
reading.
40A
~
400A
~
1000A
~
Correct Current
Measurement
Incorrect Current
Measurement
!!
8

+
-
10. DC VOLTAGE MEASUREMENT
1. Set the function switch to range
position. The meter automatically defaults to
DC Volts.
2. Insert the red test lead into the “V Ω TEMP HZ”
input terminal and the black lead to the “COM”
terminal.
3. Connect the other end of the test leads to the
circuit under test.
4. Read the display. If a “-” sign is displayed, the
red lead is the negative potential.
Note: • The meter is set to default to “Auto
Range” mode.
• Pressing the hold button will
allow the user to record the peak
maximum and minimum readings on the
AC volt range. See page 7 for further
instructions for “PEAK” Hold function.
Battery
9
PEAK
V
__
~
__ __ __
Hz

AC Supply
11. AC TRUE RMS VOLTAGE MEASUREMENT
1. Set the function switch to range
position.
2. Press the button to select the AC Volt
range. The meter automatically defaults to DC
Volts.
3. Insert the red test lead into the “V Ω TEMP HZ”
input terminal and the black lead to the “COM”
terminal.
4. Connect the other end of the test leads to the
circuit under test. Take the reading on the
display.
Note: • The meter is set to default to “Auto
Range” mode.
• Pressing the hold button will
allow the user to record the peak
maximum and minimum readings on the
AC volt range. See page 7 for further
instructions for “PEAK” Hold function.
MODE
10
PEAK
V
__
~
__ __ __
Hz

!!
12. RESISTANCE MEASUREMENT
1. Set the function switch to range
position. The meter automatically defaults to
resistance range.
2. Insert the red test lead into the “V Ω TEMP HZ”
input terminal and the black lead to the “COM”
terminal.
3. Connect the other end of the test leads to the
circuit or component under test. Take the
reading on the display.
Note: • The meter is set to default to “Auto
Range” mode.
• WARNING before attempting to
make a resistance measurement, ensure
there is no voltage present on the circuit
under test.
Resistor
11
Ω

13. CAPACITANCE MEASUREMENT
1. Set the function switch to range position.
2. Insert the red test lead into the “V Ω TEMP HZ”
input terminal and the black lead to the “COM”
terminal.
3. Connect the other end of the test leads to the
circuit or component under test. Take the
reading on the display.
Note: • In Capacitance range the meter is Auto
Ranging only.
• CAUTION to avoid damage to the
meter or the equipment under test,
remove all power from the circuit and
discharge all capacitors before
measuring capacitance.
• Large value capacitors should be
discharged through an appropriate
resistance load. Use the DC Voltage
function to confirm that the capacitor is
discharged.
Capacitor
!!
12
CAP

14. FREQUENCY MEASUREMENT
1. Set the function switch to range
position. The meter automatically defaults to
Frequency range.
2. Press the button for 3 seconds to select
the Frequency range. The meter automatically
defaults to DC Volts.
3. Insert the red test lead into the “V Ω TEMP HZ”
input terminal and the black lead to the “COM”
terminal.
4. Connect the other end of the test leads to the
circuit or component under test. Take the
reading on the display.
Note: • In the Frequency range the meter is Auto
Ranging only.
Measuring Frequency
on AC Supply
Hz
13
V
__
~
__ __ __
Hz
MODE

15. TEMPERATURE MEASUREMENT
1. Set the function switch to range position.
The meter automatically defaults to ºC range.
2. Insert the MT802 white temperature adaptor
into the “V Ω TEMP HZ” input terminal and the
“COM” terminal. Ensure that the “-” marking on
the adaptor is inserted into the “COM” terminal
and the “+” marking on the adaptor is inserted
into the “V Ω TEMP HZ” input terminal.
3. Connect any K-Type probe into the MT802
adaptor and measure the temperature of the
apparatus or area required.
4. Read the temperature directly on the display.
5. To change the measuring unit from ºC to ºF,
Press the button to select the ºF unit.
Note: • The meter is set to default to “Auto
Range” mode.
Temp
MODE
K-Type Adaptor
Ambient Temperature
K-Type
Wire Probe
14

16. DIODE TEST
1. Set the function switch to range
position.
2. Press the button to select the Diode
Test range. The meter automatically defaults to
Resistance.
3. Insert the red test lead into the “V Ω TEMP HZ”
input terminal and the black lead to the “COM”
terminal.
4. Connect the other end of the test leads to the
component under test. Read the display.
Note:• Use the diode test to check diodes,
Transistors, silicon controlled rectifiers
(SCR’s) and other semiconductor devices.
• The test sends a current through a
semiconductor junction, then measures
the junction’s voltage drop.
• Normal forward voltage drop (forward bias)
for a good silicon diode is between 0.4V to
0.9V. A reading higher than that indicates
a leaky (defective) diode. A zero reading
indicates a shorted diode.
• Reverse the test leads connection (reverse
bias) across the diode. The display shows
“OL” if the diode is good. Any other
readings indicate the diode is shorted or
resistive (defective).
MODE
Ω
Diode
15

17. CONTINUITY TESTING
1. Set the function switch to range
position.
2. Press the button to select the Continuity
Test range. The meter automatically defaults to
Resistance.
3. Insert the red test lead into the “V Ω TEMP HZ”
input terminal and the black lead to the “COM”
terminal.
4. Short the tip of the test leads and make sure the
display reads “0” and the buzzer beeps.
5. Connect the tip of the test leads to the circuit or
component under test. The display reads the
resistance and the buzzer beeps when the
reading is not more than about 35Ω.
Note: • Using resistance and continuity function
in a live circuit will produce false results and
may damage the instrument.
• In many cases the suspicious
components must be disconnected from the
circuit under test to obtain accurate
results
• WARNING before attempting to
make a test, ensure there is no voltage
present on the circuit. .
MODE
Buzzer Sounds
16
!!
Ω

18. AUTO POWER OFF
This feature automatically turns off the meter after
approximately 20 minutes from the last
measurement taken. To turn the on the meter,
press any button or move the rotary switch to any
position. Ensure te test leads are disconnected
from any circuit to avoid injury or meter damage
19. CALIBRATION
It is recommended that this digital clamp meter
should be calibrated once a year, so as to ensure
the accuracy, as well as confirming that the meter
is working on all ranges as per the specifications.
20. GUARANTEE
This product is guaranteed to be free from
defects in material or workmanship manifesting
themselves within a period of two years from date
of purchase by the first user.
This guarantee covers the ordinary and normal
operation of the product, excludes the defects
which may arise from normal wear and tear,
negligent or improper usage, a failure to maintain
the product as specified in this users manual (the
onus of satisfactory proving which shall rest upon
the owner) and any defects arising from accident.
Products which have in any manner been
tampered with are excluded from this guarantee.
In the event of malfunction within the guarantee
period, the product must be returned to Major
Tech within the period together with proof of
purchase in the form of a cash slip or invoice.
. a function used to freeze the reading on the
display, ideal for later viewing.
17

21. BATTERY REPLACEMENT
When the “ “ sign appears on the LCD, this
indicates the battery should be replaced. Use the
following procedure to replace the standard 9V
battery (IEC 6F 22) battery.
1. Disconnect the test leads from any live source
and remove the leads from the input terminals.
2. Rotate the function switch to the
position.
3. The battery cover is secured to the bottom of
the case by a screw. Using a screwdriver
remove the screw from the battery cover and
remove the battery cover from the meter.
4. Remove the old battery and replace it with a
new IEC 6F 22 9V battery.
5. Replace the battery cover and reinstall the
screw.
22. STANDARD ACCESSORIES
OFF
HDT 3914
Crocodile Clip
CAT lll 600V, CAT ll 1000V
10A Ratings
HDT 1282
ComfiGrip™ Test Leads
CAT lV 600V, CAT lll 1000V
10A Rating MT 660
K-Type Thermocouple
MT 802
4mm to K-type
Adaptor
Battery Cover
18
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+

© 2004, MAJOR TECH (PTY) LTD.
All rights reserved E&OE
MAJOR TECH
(PTY) LTD
T9 Industrial Village, Sam Green Road,
Tunney Ext. 9, Elandsfontein,
South Africa
P.O. Box 888, Isando 1600,
South Africa
Telephone: [phone]
National Contact Number: 08 61 62 5678
Sales Facsimile: [phone]
Admin Facsimile: [phone]
E-mail: [email protected]
www.major-tech.com