UNI-T UT502A Operating Manual

UT502A Insulation Resistance Tester is designed with brand-new
design and combination of massive integrated and digital circuits; it
can measure insulation resistance, low resistance, AC voltage, etc,
and enjoys high degree of accuracy, stable performance, easy
operation and reliability. It is used for insulation resistance
measurement for insulation materials and various kinds of electric
equipments such as transformer, electric machines, cables, switches,
electrical appliances, a ideal tool for electric equipment maintenance,
testing and inspection.
2. Safety Information
The instrument is designed and manufactured in compliance with
IEC61010 standard. The manual covers safety information related to
the safe operations and conditions of the instrument. please read
carefully before using the instrument.
Warning
Use always as specified in the manual, and keep it for future use.
conditions and actions that may cause serious or
fatal damage.
Alerts users to avoid electric shock.
conditions and actions that may cause damage to
the instrument or affect accurate measurement.
voltage over 750VAC.
leads
When test leads are shorted and connected to the instrument, do
not press TEST key.
during test.
Do not touch the tested line during insulation measurement.
instrument was damaged or had exposed metal.
is
discharged.
lead
lead
3. Electrical Symbols
Risk of electric shock
Accuracy: ±(a% of reading + b digits), calibration per year.
Insulation Resistance Measurement
Rated voltage
Measurement
0.00MΩ ~ 5.00GΩ 0.00MΩ ~ 5.00GΩ
range
Open circuit
DC 500V+10%
voltage
Under
Rated measurement
current 1.00mA~1.10mA
Short circuit current Approx. Less than 1.8mA
0.00MΩ~99.9MΩ: ±(3%+5)
Accuracy range
100MΩ~10GΩ: ±(5%+5)
10.0GΩ~20.0GΩ: ±(10%+5)
Polarization Index/Dielectric Absorption Ratio Measurement
PI Measurement 10min insulation resistance/1min insulation resistance
Greater than
PI Value
or equal to 4
Criterion Best
DAR Measurement 1min insulation resistance/30s insulation resistance
DAR Measurement 1min insulation resistance/15s insulation resistance
Greater than
DAR Value
or equal to 1.4
Criterion
Eg: the
Low Resistance Measurementc
Open-circuit voltage
Measurement range
Resolution ratio
Accuracy
between test leads
low battery indicator shows If
properly.
500V 1000V 2500V
0.00MΩ ~ 20.0GΩ
DC 1000V+10%
DC 2500V+10%
Under 1MΩ
500KΩ Under 2.5MΩ
1.00mA~1.10mA
1.00mA~1.10mA
Less than or
4---2 2.0---1.0
equal to 1.0
Good Warning Bad
Less than or
1.25--1.0
equal to 1.0
Best Good Bad
Approx. 5.0V
0.00~200 Ω
Ω
0.01
± (2%+3) Ω
Voltage Measurement
AC voltage
Measurement range
30~750V (50/60Hz)
Resolution 1V
Accuracy ± (2%+3)
Low battery indication:
.
Overload indication: "＞22.0GΩ" shows under insulation
resistance measurement.
display the unit and function simultaneously
●
Automatic voltage release
●
Backlight for work on dark sites
●
Red light for warning
(Altitude: <2000m)
under normal condition)
test leads,
operating manual, carrying case.
●
Safety compliances: Overvoltage CATIII 600V, Pollution
Degree 2 as per IEC61010
5. Tester's Structure(Front View)
measurement
for
7 Switch button for PI/DAR
8 TEST button
9 Rotary knob
LCD Display
6. Buttons and Rotary Knob
1. PI/DAR button: measures polarization index/dielectric absorption
ratio.
2. ZERO/LIGHT button: turns on/off the backlight or resets the
display to zero for low resistance measurement.
3. TEST button: turns on/off insulation and low resistance
measurement.
4. Rotary knob set to ACV: to measure AC voltage.
5. Rotary knob set to CONTINUITY: to measure low resistance.
measurement