Center 252 User manual

AC/DC CLAMP METER
252

TABLE OF CONTENTS
1. SAFETY INFORMATION....................................................... 1
2. GENERAL SPECIFICATION................................................. 1
3. ELECTRICAL SPECIFICATION........................................... 2
3-1 DIRECT VOLTAGE..................................................................... 2
3-2 DIRECT VOLTAGE (PEAK MODE)............................................... 2
3-3 ALTERNATING VOLTAGE ........................................................... 2
3-4 ALTERNATING VOLTAGE (PEAK MODE)....................................... 2
3-5 DIRECT CURRENT ............... ................................................. 3
3-6 DIRECT CURRENT (PEAK MODE)............................................... 3
3-7 ALTERNATING CURRENT ........................................................... 3
3-8 ALTERNATING CURRENT (PEAK MODE) ...................................... 3
3-9 RESISTANCE(Ω)....................................................................... 3
3-10 CONTINUITY() .................................................................... 3
4. DESCRIPTION OF THE INSTRUMENT ............................. 4
4-1 DESCRIPTION OF THE DISPLAY................................................... 4
4-2 DESCRIPTION OF FRONT AND REAR ............................................ 5
5. BUTTON INSTRUCTION....................................................... 6
5-1 HOLD FUNCTION .................................................................... 6
5-2 PEAK FUNCTION .................................................................... 6
5-3 ZERO FUNCTION .................................................................. 6
5-4 BACKLIGHT FUNCTION .......................................................... 6
6. MEASURING INSTRUCTION ............................................... 6
6-1 AC VOLTAGE MEASUREMENT.................................................... 6
6-2 DC VOLTAGE MEASUREMENT ................................................... 7
6-3 AC CURRENT MEASUREMENT ...... ...........................................7
6-4 DC CURRENT MEASUREMENT ................................................. 8
6-5 RESISTANCE MEASUREMENT ....................................................9
6-6 CONTINUITY MEASUREMENT .....................................................9
7. BATTERY CHANGING ........................................................ 10
8. MAINTENANCE..................................................................... 11

Clamp Meter
1
1. SAFETY INFORMATION
Do not operate the tester if the body of meter or the test lead look
broken.
Check the main function dial and make sure it is at the correct position
before each measurement.
Do not perform resistance and continuity test on a live power system.
Do not apply voltage between the test terminals and test terminal to
ground that exceed the maximum limit record in this manual.
Keep the fingers after the protection ring when measuring through the
test lead.
Chang the battery when the symbol appears to avoid incorrect
data.
Environmental Conditions
Operation Temperature: 0°C to 40°C(32°F to 104°F); < 70 % RH
Storage Temperature: -10°C to 60°C(14°F to 140°F); < 80 % RH
Explanation Symbols
Attention refer to operation Instructions.
Dangerous voltage may be present at terminals.
This instrument has double insulation.
Approvals: EN61010 600V CAT III
2. GENERAL SPECIFICATION
Digital Display:
4 digital liquid crystal (LCD), Maximum reading 6200.
Polarity:
When a negative signal is applied, the signal appears.
Low Battery Indication:
When the battery is under the proper operation range, will appear
on the LCD display.
Sample Rate:
3 times/sec.

Clamp Meter
2
Power Source:
1.5V size AAA battery X 2
Typical battery Life: 50 hours (without buzzer, backlight function)
Auto Power Off:
If there is no key or dial operation for 30 minutes, the meter will power
itself off to save battery consumption. This function can be disabled by
press and hold the “ HOLD” button then power the unit on.
Over Load:
When the signal larger than the maximum will be show .
Maximum jaw opening:
∅25 mm
Dimensions:
210 x 62 x 36 mm
Weight:
273g (with battery)
Accessories:
Carrying case, Batteries, Test Lead & Instruction Manual.
3. ELECTRICAL SPECIFICATION
Accuracy is to within ± [% of the reading + number of counts (dgts)] in
the reference conditions indicated in the appendix.
3-1 Direct Voltage
Range Resolution Accuracy
600 V 0.1 V 1% + 2dgts
Input impedance: 1 MΩ
3-2 Direct Voltage ( Peak Model )
Range Resolution Accuracy
600 V 0.1 V 1.5% + 8dgts
Input impedance: 1 MΩ
3-3 Alternating Voltage
Range Resolution Accuracy
600 V 0.1 V 1.2% + 5dgts
Input impedance: 1 MΩ
3-4 Alternating Voltage ( Peak Model )
Range Resolution Accuracy
600 V 0.1 V 1.7% + 10dgts
Input impedance: 1 MΩ

Clamp Meter
3
3-5 Direct Current
Range Resolution Accuracy
60 A 0.01 A
600 A 0.1 A 2% + 5dgts
3-6 Direct Current ( Peak Model )
Range Resolution Accuracy
600 A 0.1 A 2.5% + 8dgts
3-7 Alternating Current
Range Resolution Accuracy
60 A 0.01 A
600 A 0.1 A 2% + 5dgts
3-8 Alternating Current ( Peak Model )
Range Resolution Accuracy
600 A 0.1 A 2.5% + 10dgts
3-9 Resistance (Ω)
Range Resolution Accuracy
1000 Ω0,1 Ω1% + 2dgts
3-10 Continuity
Range Buzzer Function
Ohm < 40Ω

Clamp Meter
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4. DESCRIPTION OF THE INSTRUMENT
4-1 Description Of The Display
Auto power off indication
Polarity indication
Low battery indication
Alternative source indication
Direct source indication
Current measurement indication
Voltage measurement indication
Data hold indication
Peak data indication
Continuity test indication
Resistance measurement indication
Zero measurement indication

Clamp Meter
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4-2 Description Of Front And Rear
○
1Current Sensing Clamp
○
2Clamp opening handle
○
3Function select dial
○
4Peak button
○
5Backlight button
○
6Data hold button
○
7LCD display
○
8COM input terminal
○
9Positive input termina
○
10 Battery cabinet

Clamp Meter
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5. BUTTON INSTRUCTION
5-1 HOLD Function
It is possible to freeze the value displayed by pressing on the
"HOLD" button. To deactivate this function, press the "HOLD"
button a second time.
5-2 PEAK Function
If you press on the "PEAK" button , the display will show "PEAK"
symbol. When there is a value input that value will be indicated
frozen in the display. If a bigger peak value is input, the peak value
will be updataed and indicated frozen in the display. When you
press on the button again, the function will return to the normal
mode.
5-3 Zero Function
If you press and hold the "PEAK" button for 2 seconds or longer, the
display will show " " symbol.
When you turn on this function, the reading will become zero.
When you press on the button again, the function will return to
the normal mode.
5-4 BACKLIGHT Function
If you press on the “＂button, it will turn on the backlight
function.(The backlight is blue light. When you turn on this function,
it will light for 15 seconds)
If you press on the“＂button again, the function will be turned
off.
6. MEASURING INSTRUCTION
6-1 AC Voltage Measurement：
Switch the main function selector
to range.
Connect red test lead to “+＂
terminal and black one to the
“COM＂terminal.
Measure the voltage by touch the
test lead tips to the test circuit
where the value of voltage is
needed.
Read the result from the LCD
panel.
ICAT I
600V
I
V
AC/DC CLAMP METER
A
A
V
600 600

Clamp Meter
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6-2 DC Voltage Measurement：
Switch the main function selector
to range.
Connect red test lead to “+＂
terminal and black one to the
“COM＂terminal.
Measure the voltage by touch the
test lead tips to the test circuit
where the value of voltage is
needed.
Read the result from the LCD
panel.
6-3 AC Current Measurement：
Switch the main function selector to range.
Open the clamp by pressing the jaw-opening handle and insert the
cable to be measured into the jaw.
Close the clamp and get the reading from the LCD panel.
Note：
Before this measurement, disconnect the test lead with the meter
for safety.
In some occasion that the reading is hard to read, push the HOLD
button and read the result later.
CORRECT
 INCORRECT
I
600V
CATI I
V
AC/DC CLAMP MET ER
A
A
V
600 600

Clamp Meter
8
6-4 DC Current Measurement：
Switch the main function selector to range.
Open the clamp by pressing the jaw-opening handle and insert the
cable to be measured into the jaw.
Close the clamp and get the reading from the LCD panel.
Note：
Before this measurement, disconnect the test lead with the meter
for safety.
In some occasion that the reading is
hard to read, push the HOLD button and
read the result later.
I
CAT I
600V I
V
V
A
AC/DC CLAMP METER
600600
A

Clamp Meter
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I
600V
CATI I
AC/DCCLAMPMETER
V
V
A
A
600 600
I
600V
CATI I
AC/DC CLAMP METER
V
V
A
A
600 600
I
600V
CAT I I
AC/DC CLAMP METER
V
V
A
A
600 600
6-5 Resistance Measurement
Switch the main function to range.
Connect red test lead to “+＂terminal
and black one to the "COM＂terminal.
Connect tip of the test leads to the
points where the value of the resistance
is needed.
Read the result from the LCD panel.
Note：
When take resistance value from a
circuit system, make sure the power
is cut off and all capacitors need to
be discharged.
6-6 Continuity Test With Buzzer：
Switch the main function to range.
Connect red test lead to “+＂terminal and black one to the
“COM＂terminal.
Connect tip of the test leads to the points where the conduction
condition needed.
If the resistance is under 40Ω, the beeper will sound continuously.
Short circuit Open circuit

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7. BATTERY CHANGING
When the battery voltage drop below proper operation range the
symbol will appear on the LCD display and the battery needs to be
changed.
Before changing the battery, switch the main dial to “OFF ”and
disconnect test leads.
Open the back cover by a screwdriver.
Replace the old batteries with two new 1.5V(AAA Size) battery.
Close the back cover and fasten the screw.

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8. MAINTENANCE
WARNING!
Before open the meter, disconnect both test lead and never uses the
meter before the cover is closed.
CAUTION!
To avoid contamination or static damage, do not touch the circuit
board without proper static protection.
8-1 REMARK:
yIf the meter is not going to be used for a long time, take out the
battery and do not store the meter in high temperature or high
humidity environment.
yWhen take current measurement, keep the cable at the center of the
clamp will get more accurate test result.
yRepairs or servicing not covered in this manual should be performed
only by qualified personal.
8-2 CLEANING:
Periodically wipe the case with a dry cloth. Do not use abrasives or
solvents on these instruments.

MEMO:

MEMO:

CENTER TECHNOLOGY CORP.
4 / F NO. 415, Jung-Jeng Rd., 238 Shu-Lin, Taipei, Taiwan
TEL : [phone] E-Mail : [email protected]
FAX : [phone] http : / / www.centertek.com
GCA000252-02000