Kusam-meco KM 255 User manual

PC-Comm
MAX 0.6A
HBC FUSED
MAX 8A
HBC FUSED
ACOM
JACK
300V CAT IV
600V CAT III
1kV CAT II
!
Temp
W
V
JACK
mA
mA
mA
mA
mV A
W
V
V
Temp
Auto
Check
(Loz)
OFF
REC
CREST
SELECT RANGE REL HOLD
Hz EF
AUTO
H
LoZ
C
MAX MIN
MW
kHz
F
mVA
8888
DIGITAL
MULTIMETER
MODEL - KM 255 / KM 257
we damage them or “burn them out”. If you incorrectly

Title Page
Safety................................................................. 01
Cenelec Directives.............................................04
General Specifications.......................................04
Electrical Specifications..................................... 07
International Electrical Symbols.........................13
Product Description............................................14
Operation............................................................18
Maintenance......................................................32
Test Certificate...................................................35
Warranty.............................................................36
TABLE OF CONTENTS
V : Category II 1000V, CAT III 600V and
CAT IV 300V AC & DC.
mAmA : Category III 500VAC and 300VDC.
A : Category III 600VAC and 300VDC.
1) SAFETY
Terms in this manual
WARNING : Identifies condition and actions that
could result in serious injury or even
death to the user.
CAUTION : identifies conditions and action that
could cause damage or malfunction in
the instrument.
This manual contains information and warning that
must be followed for operating the instrument safely
and maintaining the instrument in a safe operating
conditions. If the instrument is used in a manner
not specified by the manufactures, the protection
provided by the instrument may be impaired. The
meter is intended only for indoor use.
The meter protection rating against the users, is
double insulation per IEC61010-1 2nd Ed.
EN61010-1 2nd Ed. UL61010-2nd Ed. and CAN/
CSA C22.2 No. 61010.1-1-0.92 to category II
1000V, CAT III 600V & CAT IV 300V AC & DC.
Terminals ( to COM) measurement category:
1

Measurement Category II (CAT II) is for
measurements performed on circuits directly
connected to the low voltage installation. Examples
are measurements on household appliances,
portable tools and similar equipment
Measurement Category III (CAT III) is for
measurements performed in the building
installation. Examples are measurements on
distribution boards, circuit-breakers, wiring,
including cables, bus-bars, junction boxes,
switches, socket-outlets in the fixed installation, and
equipment for industrial use and some other
equipment, for example, stationary motors with
permanent connection to the fixed installation.
Measurement Category IV (CAT IV) is for
measurements performed at the source of the low-
voltage installation. Examples are electricity meters
and measurement on primary overcurrent
protection devices and ripple control units.
Per IEC61010-1 2nd Ed. (2001) Measurement
Category
2
To reduce the risk of fire or electric shock, do not
expose this product to rain or moisture. To avoid
electrical shock hazard, observe the proper safety
precautions when working with voltage above
60 VDC or 30 VAC rms. These voltage levels pose
a potential shock hazard to the user. Do not touch
test lead tips or the circuit being tested while power
is applied to the circuit being measured. Keep your
fingers behind the finger guards of the test leads
during measurement. Inspect test leads,
connectors, and probes for damaged insulation or
exposed metal before using the instrument. If any
defects are found, replace them immediately. Do
not measure any current that exceeds the current
rating of the protection fuse. Do not attempt a
current measurement to any circuit where the open
circuit voltage is above the protection fuse voltage
rating. Suspected open circuit voltage should be
checked with voltage functions. Never attempt a
voltage measurement with the test lead inserted
into the mA/mA or A input jack. Only replace the
blown fuse with the proper rating as specified in
this manual.
Disconnect the test leads from the test points
before changing functions. Always set the
instrument to the highest range and work
downward for an unknown value when using
manual ranging mode.
Warning
CAUTION
3

The instruments conforms to CENELEC Low-voltage
directive 2006/95/EC and Electromagnetic
compatibility directive 2004/108/EC
?Display : 3-5/6 digits 6,000 counts
?Update Rate : 5 per second nominal
?24 Segments Bar graph :40 per second max.
?Operating Temperature : 0°C to 40°C
?Relative Humidity : Maximum relative
humidity 80% for temperature up to 31°C
decreasing linearly to 50% relative humidity
at 40°C
?Altitude : Operating below 2000m
?Storage Temperature : -20°C~60°C,
<80% R.H. (With battery removed)
?Temperature Coefficient : Nominal 0.15 x
(specified accuracy) / °C @ (0°C~18°C or
28°C~ 40°C), or otherwise specified.
?Sensing :
KM255 : Average sensing
KM257 : True RMS sensing
2) CENELEC DIRECTIVES
3) GENERAL SPECIFICATION
4
?Pollution Degree : 2
?Safety : Double insulation per IEC61010-1 2nd Ed.
EN6100-1 2nd Ed., UL61010-1 2nd Ed. &
CAN / CSA C22.2 No. 61010.1-0.92 to
Category II 1000V, CAT III 600V and
CAT IV 300V AC & DC
?Transient Protection : 6.5kV (1.2/50ms surge)
?Terminals (to Com) Measurement Category :
V : Category II 1000V, CAT III 600V and
CAT IV 300V AC & DC.
mAmA : Category III 500VAC and 300VDC.
A : Category III 600VAC and 300VDC.
?E.M.C. : Meets EN61326 -1:2006 (En55022,
EN61000-3-2, EN61000-4-2,
EN61000-4-3, EN61000-4-4,
EN61000-4-5, EN61000-4-8,
EN61000-4-11)
In an RF field of 3V/m:
Capacitance function is not specified
Other function ranges:
Total Accuracy = Specified Accuracy+100 digits
Performance above 3V/m is not specified
?Overload Protection :
mA & mA : 0.63A/500Vac, IR 150kA @500Vac
A : 10A/600Vac IR 100kA@600Vac
V : 1050 Vrms, 1450 Vpeak
AutoCheckä, mV, Ohm & others : 600 Vrms
5

6
?Low Battery : Blow approx. 2.3V
?Power Supply: 1.5V AAA Size battery x 2
?Power Consumption (typical): 3.5mA
?APO Consumption (typical) : 10mA
?APO Timing : Idle for 34 minutes
?Dimension :161(L) x 80(W) x 50(H)mm
(With Holster)
?Weight : Approx. 340 gm (With Holster)
?Special Features : AutoCheckäV&W;
Auto-ranging MAX / MIN record ; Crest mode
(Peak Hold), Backlighted LCD ; Auto-ranging
Relative Zero mode; Display Hold; EF-
Detection (NCV); Interface capabilities with
PC computer; Input warning detection.
?Optional purchase accessories :
USB interface kit BRUA-20; Magnetic hanger
BMH-01; BKB32 banana plug to type-K
socket plug adaptor.
?Accessories :
Test lead pair : batteries installed ;
user’s manual; BKP 60 banana
plug type-K thermocouple.
7
True RMS model KM257 ACV & ACA accuracies
are specified from 5% to 100% of range or other-
wise specified . Maximun Crest Factor <3:1 at full
scale & 6:1 at half scale, and with frequency
components fall within the meter specified
frequency bandwidth for non-sinusoidal waveforms.
AC Voltage
4) Electrical Specification
Accuracy is given as ±(%of reading digits + number
of digits) or otherwise specified @ 23°C±5°C and
less than 75% R.H.
Range
50Hz ~ 400Hz
60.00 mV
600.0 mV
6.000 V
60.00 V
600.0 V
1000 V
Resolution Accuracy
±(1.0%rdg + 5dgts)
CMRR : >60dB @ DC to 60Hz, Rs= 1kW
Input Impedance : 10MW, 50 pF nominal
DC Voltage
NMRR : >60dB @ DC to 50Hz / 60Hz
CMRR : >100dB @ DC, 50Hz / 60Hz; Rs= 1kW
Input Impedance : 10MW, 50 pF nominal
Range
60.00 mV
600.0 mV
6.000 V
60.00 V
600.0 V
1000 V
Resolution Accuracy
±(0.2%rdg + 3dgts)
10 mV
100 mV
1 mV
10 mV
100 mV
1 V
10 mV
100 mV
1 mV
10 mV
100 mV
1 V

AutoCheckä_ACV
AutoCheckäLo-Z ACV Thershold : >1V nominal
AutoCheckäLo-Z ACV input Impedance:
Initially approx. 2.5kW, 120pF nominal;
Impedance increases abruptly within a fraction of a
second as display voltage is above 50V(typical).
Ended up impedance vs display voltages typically are:
15kW@100V
100kW@300V
250kW@600V
375kW@1000V
Range
50Hz / 60Hz
1.000V~1000V
AutoCheckä_DCV
TM
AutoCheck Lo-Z DCV Threshold :
>+1.0VDC & <-1.0VDC nominal.
TM
AutoCheck Lo-Z DCV Input Impedance :
Initially approx. 2.5kW, 120pF nominal;
Impedance increases abruptly within a fraction of a
second as display voltage is above 50V(typical).
Ended up impedances vs display voltages typically are :
15kW@ 100V
100kW@ 300V
250kW@ 600V
375kW@ 1000V
8
Accuracy
±(1.4%rdg+5dgts)
Resolution
1mV~1V
Range
50Hz / 60Hz
1.000V~1000V
Accuracy
±(1.3%rdg+3dgts)
Resolution
1mV~1V
Resistance
Open Circuit Voltage : 0.45VDC typical.
Range
600.0 W
6.000 KW
60.00 KW
600.0 KW
6.000 MW
600.00 MW
Resolution Accuracy
±(0.5%rdg + 4dgts)
±(0.7%rdg + 4dgts)
±(1.2%rdg + 4dgts)
CREST Mode :
Accuracy : Specified accuracy plus 150 digits for changes
> 5ms in duration.
RECORD Mode :
Accuracy : Specified accuracy plus 100 digits for change
>100ms in duration.
TM
Autocheck Ohm :
1)
Range Accuracy
00.00W~ 60.00MW
±(1.2%rdg+10dgts)
Open Circuit Voltage : 0.45VDC typical.
1) TM
AutoCheck Ohm Threshold : < 10.00MWnominal
Audible Continuity Tester:
AudibleThreshold Response time
32ms
Between 10Wand 80W
9
100 mW
1 W
10 W
100 W
1 kW
10 kW
Resolution
10mW~10kW

11
AC Current
Range Resolution Accuracy
600.0 mA
6000 mA
60.00 mA
600.0 mA
6.000 mA
1)
8.00 A
±(1.0%rdg + 3dgts)
Burden Voltage :
0.10mV/mA (600.0mA & 6000mA) ranges.
1.7mV/mA (60.00mA & 600.0mA) ranges
1)
0.03V/A (6.000mA & 8.00A ) ranges.
1) 8A Continuous, > 8A to 15A for 30 Sec. Max. with
5 minutes cool down interval.
50Hz ~ 400Hz
10Hz - 50kHz
10Hz - 10kHz
10Hz - 10kHz
10Hz - 10kHz
10Hz - 10kHz
10Hz - 10kHz
10Hz - 50 kHz
10Hz - 1kHz
10Hz - 1kHz
45Hz - 1kHz
Sensitivity
(sine RMS)
400 mA
400 V
40 mA
40 mA
0.4 V
40 V
4 mA
6 A
1 A
4 V
Function
6000 mA
600 mA
600 mA
600 V
1000 V
60 mA
6 V
60 V
6 A
10 A
Hz (Line ) @ ACV, DCV, Current & AutoCheckä
Range
Accuracy : 0.03% + 3d
100 nA
1 mA
10 mA
100 mA
1 mA
10 mA
10
Accuracies with film capacitor or better
Capacitance
Range
60.00 nF
600.0 nF
6.000 mF
60.00 mF
600.0 mF
3000 mF
Resolution Accuracy
±(2.0%rdg + 5dgts)
±(1.5%rdg + 5dgts)
±(2.0%rdg + 5dgts)
Diode Tester
Range Accuracy
Test Current : 0.56mA typical.
Open Circuit Voltage : <1.8VDC typically.
±(1.0%rdg + 3dgts)
1.000 V
DC Current
Range
600.0 mA
6000 mA
60.00 mA
600.0 mA
6.000 mA
1)
8.00 A
Resolution Accuracy
±(0.5%rdg + 3dgts)
Burden Voltage :
0.10mV/mA (600.0mA & 6000mA) ranges.
1.7mV/mA (60.00mA & 600.0mA) ranges
1)
0.03V/A (6.000mA & 8.00A ) ranges.
1) 8A Continuous, > 8A to 15A for 30 Sec. Max. with
5 minutes cool down interval.
10 pF
100 pF
1 nF
10 nF
100 nF
1 mF
Resolution
100 mV
100 nA
1 mA
10 mA
100 mA
1 mA
10 mA

12
Bar-Graph
Indication
Typical Voltage
Temperature
Range Accuracy
-50°C ~ 1000°C
-58°F ~ 1832°F ±(0.3%rdg + 6dgts)
±(0.3%rdg + 3dgts)
K Type Thermocouple range & accuracy not included.
Supplied Thermocouple suitable for measurement
upto 250°C.
Logic Level Hz (mV Function)
Range Sensitivity (square wave)
5.00Hz ~ 500.0kHz 3 Vpeak
Accuracy : 0.03% + 2d.
5.00Hz ~ 1.000MHz 5 Vpeak
Non-Contact EF-Dection :
440V (tolerance:250V~1000V)
220V (tolerance:124V~330V)
110V (tolerance:59V~165V)
55V (tolerance:23V~83V)
20V (tolerance:10V~36V)
Indication : Bar-graph segments & audible beep tones
proportional to the field strength.
Detection Frequency : 50 / 60Hz
Detection Antenna : Top-right end of the meter
Probe-Contact EF-Detection: For more precise indication
of live wires, such as distinguishing between live &
ground connections, use the Red (+) test probe for
direct contact measurements.
13
~
5) INTERNATIONAL ELECTRICAL SYMBOLS
Caution ! Refer to the explanation in this
Manual
Caution ! Risk of electric shock
Earth(Ground)
Double insulation or Reinforced insulation
Fuse
AC--Alternating Current
DC--Direct Current

15
Analog bar-graph
The analog bar graph provides a visual indication
of measurement like a traditional analog meter
needle. It is excellent in detecting faulty contacts,
identifying potentiometer clicks, and indicating
signal spikes during adjustments.
Average sensing RMS calibrated
RMS (Root-Mean-Square) is the term used to
describe the effective or equivalent DC value of an
AC signal. Most digital multimeters use average
sensing RMS calibrated technique to measure
RMS values of AC signals. This technique is to
obtain the average value by rectifying and filtering
the AC signal. The average value is then scaled
upward (calibrated) to read the RMS value of a
sine wave. In measuring pure sinusoidal waveform
this technique is fast, accurate and cost effective.
In measuring non-sinusoidal waveforms, however,
significant errors can be introduced because of
different scaling factors relating average to RMS
values.
True RMS
True RMS is a term which identifies a DMM that
responds accurately to the effective RMS value
regardless of the waveforms such as: square,
sawtooth, triangle, pluse trains, spikes, as well as
distorted waveforms with the presence of
harmonics. Harmonics may cause:
14
6) PRODUCT DESCRIPTION
Note: Top of the line model is used as representative
for illustration purposes. Please refer to your
respective model for function availability.
PC-Comm
MAX 0.6A
HBC FUSED
MAX 8A
HBC FUSED
ACOM
JACK
300V CAT IV
600V CAT III
1kV CAT II
!
Temp
W
V
JACK
mA
mA
mA
mA
mV A
W
V
V
Temp
Auto
Check
(Loz)
OFF
REC
CREST
SELECT RANGE REL HOLD
Hz EF
AUTO
H
LoZ
C
MAX MIN
MW
kHz
F
mVA
8888
1
2
3
4
5
6
7
1. 3-5/6 digits
6000 counts
LCD display
2. Push-buttons
for special
functions &
features
3. Selector to
turn the Power
On or Off &
Select a function
4. Input Jack for
milli-amp and
micro-amp
current functions
5. Input Jack for all functions EXCEPT current
(mA, mA, A) functions
6. Common (Ground reference) Input Jack for all
functions.
7. Input Jack for 8A (15A for 30sec) current
function

16
3) Fuses to blow
4) Neutrals to overheat due to the triplen
harmonics present on the neutral
5) Bus bars and electrical panels to vibrate
1) Overheated transformers, generators and
motors to burn out faster than normal
2) Circuit breakers to trip prematurely
Crest Factor is the ratio of the Crest
(instantaneous peak) value to the True RMS
value, and is commonly used to define the
dynamic range of a True RMS DMM. A pure
sinusoidal waveform has a Crest Factor of 1.4 A
badly distorted sinusoidal waveform normally has
a much higher Crest Factor.
Crest Factor
NMRR is the DMM’s ability to reject unwanted AC
noise effect that can cause inaccurate DC
measurements. NMRR is typically specified in
terms of dB(decibel). This series has a NMRR
specification of >60dB at 50 and 60Hz, which
means a good ability to reject the effect of AC
noise in DC measurements.
NMRR (Normal Mode Rejection Ratio)
17
Common mode voltage is voltage present on both
the COM and VOLTAGE input terminals of a DMM,
with respect to ground. CMRR is the DMM’s ability
to reject common mode voltage effect that can
cause digit rolling or offset in voltage
measurements. This series has a CMRR
specifications of >60dB at DC to 60Hz in ACV
function; and >120dB at DC, 50 and 60 Hz in DCV
function. If neither NMRR nor CMRR specification
is specified, a DMM’s performance will be
uncertain.
CMRR (Common Mode Rejection Ratio)