GW Instek GCM-302 User manual

Please read this instruction manual before using the
meter and keep it properly for contingent use.
To avoid danger and damage happened during operation,
the following symbols are used as points for attention.
Improper use of the meter may bring
hurt or even death to body. Please
read the operation carefully.
Improper use of the meter may bring
hurt or even death to body. Please
read the operation carefully.
:Warning:
:Caution:
:Dual insulation
:Grounding - Earth Terminal
:AC - (Alternating Current) voltage / current
:DC - (Direct Current) voltage
PRECAUTION:
Warning
To prevent electrical shock or fire!
Before measurement, make sure that the test leads
and function switch has been set properly.
Before switching among functions, remove the test
leads off the measured object.
Before measurement, make sure the circuit current
of object won't exceed the maximum measurement
range.
Do not use this meter if any crack or damage
occurred in the case or test leads.
Do not open the case of meter or the battery lib
during measurement.
Please keep your hands behind the guard ring of
test leads while measuring with test leads.
Please keep your hands below the guard ring of the
meter while measuring with sensoring jaw.
Before proceeding resistance measurement, turn
off the power to the circuit under test first.
Never use the meter in rainy or humid environment
or with wet hands.
Before proceeding current measurement, make
sure to remove the test leads from the input
terminals.
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-1- -2-

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Jaw
Opening of the jaw
Guard ring
Clamp trigger
Function switch knob
Keep your hands below the
guard ring of the meter while
measuring with sensoring jaw.
Press down the trigger to open
the jaw.
Position the conductor in the
center of jaw in order to ensure
the accuracy of reading while
measuring current.
-4-
Warning
Caution
To prevent damage to the meter or electrical
shock!
According to the safety standard, the maximum voltage
input power is classified as follows to protect the users
against transient impulse voltage in power lines.
Over-voltage Category (CAT.) Maximum input voltage
Do not use the meter near equipment emitting noise or
under an environment with sudden temperature
change; otherwise, unstable or erroneous reading will
appear.
Take the batteries out of the meter if it will be left idle for
a long time.
After measurement, switch the function knob back to
OFF position. As there will be slight power consumption
under auto power off mode.
Please position the conductor in the center of jaw in
order to ensure the accuracy of measurement while
measuring current.
Please make sure to keep out of high current to ensure
the accuracy of measurement while measuring
current.
Do not use organic solvent to clean the meter but with a
soft cloth if necessary.
Do not expose the meter under direct sunshine or
extreme temperature or in moisture places.
When the measurement values appear irregularly
or the symbol displays, replace the batteries
immediately to ensure normal operation.
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CAT II 600V
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-3-
Turn off the power
AC current measurement
AC voltage measurement
DC voltage measurement
Resistance measurement
Diode / Continuity check
/
( 1 ) NAME OF PARTS
OFF
A
V
V
6
7
2
8
11
1
3
4
5
9
10
MAX
SELECT
OFF
COM
VV
A
600V
AC
CLAMP METER
AUTO RANGE
Press MAX key during
measurement, symbol will
appear on the LCD; and the
maximum value will be locked
and renewed instantaneously.
To cancel this function, just
press MAX key again and
ymbol will disappear.
This function is only
applicable to , &
s
Note:
MAX
MAX
6MAX key
A V V
CAT

Transform between diode and continuity check.
Mark product brand and model number
SELECT key
Name plate
LCD Display
Show measurement
symbols, units and values
-6--5-
AUTO
,
MAX
,,
+
7
8
9
10
11
,
AUTO
MAX
(2) MEASURING INSTRUCTIONS
nAC Current Measurement ( )
Measuring range: 200A~600A (2 ranges, auto-ranging)
1.Set the function switch knob on
2.Press down the clamp trigger to open the jaw, place one
conductor in the center of the jaw (as below drawing),
then read the value when it stabilizes.
Please put the conductor in the center of jaw in
order to avoid serious inaccuracy
3.The meter will choose the appropriate range to measure
automatically.
4.When measurement finished, set the function switch
knob OFF position to turn off the meter.
If the measurement is conducted in a place with dim
light, you may press MAX key to lock the value
measured and read it in other places with proper
illumination.
Note:
Note:
on
A
A
Symbols / Units Description
Lit when in DC mode measurement
Lit when in AC mode measurement
Negative polarity indicator
Lit when in continuity check
Auto-ranging indicator
Low battery indicator
Unit for current measurement
Unit for voltage measurement
Unit for resistance measurement
Maximum value lock indicator
Lit when in diode measurement
Measured value display
,
MAX
SELECT
OFF
VV
A
AC AC
CLAMP METER
AUTO RANGE
CLAMP METER
AUTO RANGE
OFF
VV
A
SELECT
MAX
COM Terminal
terminal
For connecting the negative input end (black test lead) for
DCV, ACV, &measurement
For connecting the positive input end (red test lead) for DCV,
ACV, &measurement

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AC Voltage Measurement ( )
DC Voltage Measurement ( )
Measuring range: 2V-600V (4 ranges, auto-ranging)
1.Set the function switch knob on
2.Plug the black test lead into COM terminal and the red
one into terminal
3.Connect the test leads to the
cir uit under test and then
read the value when
it stabilizes
4.The meter will choose
the appropriate range to
measure automatically
5.When measurement finished,
set the function switch knob
n OFF position to turn off
he meter.
Measuring range: 200mV-600V (5 ranges, auto-ranging)
1.Set the function switch knob on
2.Plug the black test lead into COM terminal and the red
one into terminal
3.Connect the test leads to the
circuit under test and then
read the value when it
stabilizes
4.The meter will choose the
appropriate range to measure
utomatically
6.When measurement finished,
set the function switch knob on
OFF position to turn off the meter.
c
o
t
a
-7- -8-
V
V
V
V
+
+
nResistance Measurement ( )
Measuring range: 200 -20M (6 ranges, auto-ranging)
1.Set the function switch knob on
2.Plug the black test lead into COM terminal and the
red one into terminal
3.Connect the test leads to the circuit under test and
then read the value when it stabilizes
4.The meter will choose the appropriate range to
measure automatically
5.When measurement finished, set the function switch
knob on OFF position to turn off the meter.
: Before undergoing resistance measurement,
firstly switch off the power to the circuit under
test and fully discharge the capacitor.
+
600V
COM
MAX
SELECT
OFF
VV
A
AC
CLAMPMETER
AUTO RANGE
12 V
600V
COM
MAX
SELECT
OFF
VV
A
AC
CLAMPMETER
AUTO RANGE
600V
COM
MAX
SELECT
OFF
VV
A
AC
CLAMP METER
AUTO RANGE
CAT

nDiode Check ( )
1.Set the function switch knob on
2. Symbol will appear on the LCD
3.Connect the test leads to the diode and then read the
value when it stabilizes
(A)Forward-bias Diode Test
Connect black test lead to the cathode and red one to
the anode
Note that reading close to 0V represents a short-
circuit and "OL" symbol indicates an open-circuit.
(B)Reverse-bias Diode Test
Connect black test lead to the anode and red one to
the cathode. Normally, it shows OL on display,
indicating that the diode under test is normal. The
diode is defective if the display gives a certain
voltage level.
4.When measurement finished, set the function
on OFF position to turn off the meter.
Silicon diode value reading approximate 0.5~0.7V
Germanium diode value reading approximate 0.5~0.7V
switch
knob
-9- -10-
nContinuity Measurement ( )
1.Set the function switch knob on
2.Press SELECT key until symbol appears on LCD
3.Plug the black test lead into COM terminal and the red
one into terminal
4.Connect the test leads to the circuit under test. If
circuit is continuous or less than 60 (+
_20 ), the
beeper will sound
5.When measurement finished, set the function switch
knob on OFF position to turn off the meter.
When power on the meter and you don't touch any key
or function switch knob for 15 minutes, the meter will
turn the power off automatically. One minute before
the meter shut down, the alarm sounds to warn the
users. Once the meter turns the power off already, you
can press the MAX key to regenerate the meter again.
(3) AUTO POWER OFF (POWER-SAVING)DEVICE
+
B
A
Red testing lead
Black testing lead
MAX
SELECT
OFF
600V
COM
VV
A
AC
CLAMPMETER
AUTO RANGE
MAX
SELECT
OFF
600V
COM
VV
A
AC
CLAMPMETER
AUTO RANGE
MAX
SELECT
OFF
600V
COM
VV
A
AC
CLAMPMETER
AUTO RANGE

-11- -12-
(4) Replacing Batteries
(5) Battery Replacement Steps
If symbols appears, the batteries fall below the normal
operation voltage. Replace them with 2 new batteries.
(Standard UM-4 or R03 AAA batteries)
Before replacing batteries, make sure to disconnect
the clamp meter from the circuit under test.
Replace two new batteries at the same time, and make
sure you put the batteries at correct polarities.
1.Abort the measuring action
2.Turn the function switch knob
back to OFF
3.Remove the screw on the back of
casing (as drawing)
4.Open the battery lid
5.Load the new batteries
6.Install the battery lid into the casing
nd fasten it with the screw
CAUTION
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(6) Specification
1. General Specification:
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Alkaline batteries approx. 400 hours
General batteries approx. 240 hours
Max Clamp Size:
Measurement Functions:
Additional Functions:
LCD Display:
Range:
Sampling Rate:
Operation Temperature/Humidity:
Storage Temperature/Humidity:
Power Supply:
Battery Life:
Dimensions:
Weight:
30mm or 10x35mm
,,,
Max hold, auto power off
Unit & function indication, 1999 digits as maximum
reading, negative polarity indicator, overload
indicator ( "OL" indicating overload of resistance,
beeper, diode), indicating low battery.
Auto-ranging
approx. 3 times per second
0 C~50 C (32 F~122 F) / below 80% R.H.
(no condensation)
-10 C~60 C (14 F~140 F) / below 70% R.H.
o condensation)
2 pcs of standard UM-4 or R03 AAA
batteries
189mm(L) x 71mm(W) x 37mm(H)
approx. 200g (batteries included)
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(n
V
V
A
Remove the screw
on the back of casing
Battery lid
1.5V
SIZE "AAA"
1.5V
SIZE "AAA"
TO AVOID ELECTRICAL
SHOCK, REMOVE TEST
LEADS BEFORE
OPENING CASE.
DO NOT USE ON BARE
CONDUCTORS.
PLEASE READ
MANUAL FOR SAFETY
BEFORE USING.
USE BATTERY 1.5V X2
AAA SIZE
WARNING
DANGER

-13- -14-
nResistance measurement (set on )
nDiode check (set on )
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Comply with Safety Standard:
Accessories:
Optional Accessories:
2. Electrical Specification:
IEC 61010-1 600V CAT
Pollution degree 2
AAA 1.5V ..............2 (inside the case)
Test leads.......................................1
Instruction manual ..........................1
Carrying case.................................1
AC Line Splitter
Environment temperature/ humidity:
rdg: reading digits
dgt: decimal digits
(Direct measuring with no necessity to
split the wire away by negative and positive
independently. Hence, it also can amplify
he small current by 10 times for easy reading)t
n
n
ACA measurement (set on )
ACV measurement (set on )

V
A
nDCV measurement (set on )
V
Specification and outward appearance of the product described above may be
revised for modification without prior notice.
23 +
_5 C/ below 80% R.H.
nContinuity check (set on )
X1
X10
GCM-302
GCM-302
GCM-303
GCM-303
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