UNI-T UT501, UT502 Operating Manual

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UT501/UT502 OPERATING MANUAL

Table of Contents

Title Page

Introduction
Unpacking the Meter
Safety Information
International Electrical Symbols
The Meter Structure
Key Functions
Rotary Switch

Measurement Operation

A. Measuring Voltages
B. Measuring Insulation Resistance

4
4

6
11
12
14
15
16
16
18

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UT501/UT502 OPERATING MANUAL

Maintenance

A. General Service
B. Replacing the Battery

Specifications

Safety and Compliances
Physical Specifications
General Specifications
Feature Summary
Detailed Accuracy Specifications
A. Voltage Measurement
B. UT501: Insulation Resistance Measurement
UT502: Insulation Resistance Measurement

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21
23
25
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26
27
27
28
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29
30

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List of Tables

Table Title Page

1. Unpacking Inspection

2. International Electrical Symbols

3. Meter Front Description

4. Key Description

5. Rotary Switch Description

List of Figures

Figure Title Page

1. The Meter Front Structure

2. Voltages Measurement

3. Insulation Resistance Measurement

4. Battery Replacement

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11
13
14
15

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16
18
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UT501/UT502 OPERATING MANUAL

Introduction

Uni-Trend Model UT501 and UT502 insulation resistance tester (hereafter, "the Meter")
is a handheld instrument designed primarily to make resistance/ insulation resistance,
DC/AC Voltage measurement.

Unpacking the Meter

The Meter includes the following items:

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UT501/UT502 OPERATING MANUAL

Table 1. Unpacking Inspection

Description

English Operating Manual
Test Lead
Test probe
Alligator clip
Carry bag
Strap

1.5V Battery (LR14)

Item

1
2
3
4
5
6
5

Qty

1 piece

1 set
1 set

1 set
1 piece
1 piece

6 pieces

In the event you find any missing or damage, please contact your dealer immediately.

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UT501/UT502 OPERATING MANUAL

Safety Information

This Meter complies with the standards IEC61010 -1 safety measurement requirement:
in pollution degree 2, overvoltage category (CAT. III 600V, CAT.II 1000V) and double
insulation.

CAT II: Local level, appliance, portable equipment etc., with smaller transient voltage
overvoltages than CAT. III
CAT III: Distribution level, fixed installation, with smaller transient over voltages than
CAT. IV

Use the Meter only as specified in this operating manual, otherwise the protection
provided by the Meter may be impaired.

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UT501/UT502 OPERATING MANUAL

Danger identifies conditions and actions that pose hazard(s) to the user.
Warning identifies avoiding electric shock.
Caution identifies conditions and actions that may damage the Meter and carrying
out accurate measurement.

International electrical symbols used on the Meter and in this Operating Manual are
explained on page 11.

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UT501/UT502 OPERATING MANUAL

Danger
Use of instrument in a manual not specifed by the manufactuer may impair
safety features/protection provided by the equipment. Read the following safety
information carefully before using or servicing the instrument.
Do not apply more than 1000V DC or 750V AC.
Do not use the Meter around explosive gas, vapor or dust.
Do not use the Meter in a wet environment.
When using the test leads, keep your figures away from the lead contacts.
Keep your figures behind the finger guards on the leads.
Do not use the Meter with any parts or cover removed.
When carrying out insulation measurement, do not contact the circuit
under test.

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UT501/UT502 OPERATING MANUAL

Warning

Do not use the Meter if it is damaged or metal part is exposed. Look for
cracks or missing plastic.
Be careful when working above 30V rms, 46.7V ac rms and 70V DC. Such
voltages pose a shock hazard.
Do not change battery when the Meter is in wet environment.
Place test leads in proper input terminals. Make sure all the test leads
are firmly connected to the Meterís input terminals.
Make sure the Meter is turned off when opening the battery compartment.
Carefully read the operating manual before operating the Meter.
Follow the operating manual all the time when using the Meter and keep
the operating manual in a safe place.
Wrong operation will cause incident and damage to the Meter.

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UT501/UT502 OPERATING MANUAL

Caution

When performing resistance tests, remove all power from the circuit to

be measured and discharge all the power.

When servicing the Meter, use only the same model number or identical
electrical specifications of test leads and power adaptor.
Do not use the Meter if the battery indicator ( ) shows a battery
empty condition. Take the battery out from the Meter if it is not used
for a long time.
Do not use or store the Meter in an environment of high temperature,
humidity, explosive, inflammable and strong magnetic field. The

performance of the Meter may deteriorate after dampened.

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UT501/UT502 OPERATING MANUAL

International Electrical Symbols

International symbols on the Meter and in this manual are explained in Table 2.
Table 2. International Electrical Symbols

Equipment protected by double or
reinforced insulation.
DC Measurement
AC Measurement
Grounding
See Manual
Conforms to Standards of European
Union

DCV
ACV

UT501/UT502 OPERATING MANUAL

The Meter Structure

Below Figure 1 and Table 3 shows the Meter front structure and description.

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Figure 1. The Meter Front Structure

a.UT501 b.UT502

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Table 3. Meter Front Description

EARTH: Resistance input terminal
G: Voltage Measurement input negative terminal
V: Voltage input terminal
LINE: Resistance input terminal
LCD
Display Backlight button
Data Hold button
Insulation Resistance Button
Rotary switch

1
2
3
4
5
6
7
8
9

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Key Functions

Table 4. Key Description

HOLD Press once to turn the data hold on, is shown on the display.

Press again to turn the data hold feature off. is disappeared.

LIGHT Press once to turn the display backlight on.

Press again to turn the display backlight off.

TEST Press to stop or start an insulation resistance test.

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UT501/UT502 OPERATING MANUAL

Rotary Switch

Table 5. Rotary Switch Description

ON/OFF Turn on or off the Meter.
ACV Turn the rotary switch to ACV to measure AC Voltage
DCV Turn the rotary switch to DCV to measure DC Voltage
250V/500V/1000V Turn the rotary switch to 250V/500V/1000V, select the
(UT501 ) requested output voltage, to carry out insulation

resistance measurement.
500V/1000V/2500V Turn the rotary switch to 500V/1000V/2500V, select
(UT502 ) the requested output voltage, to carry out insulation
resistance measurement.

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Figure 2. Voltages Measurement

a.UT501 b.UT502

Measurement Operation

Below section explains how to make measurements.

A. Measuring Voltages

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Catuion

To avoid harm to you or damages to the Meter from electric shock, do not

attemptto meaure voltages higher than 1000V DC or 750V rms AC although
readings may be obtained.

When voltage measurement has been completed, disconnect the connection
between the testing leads and the circuit under test and remove testing leads away
from the input terminals of the Meter.
Do not carry out measurement when the battery compartment is open.
To measure voltages, set up the Meter as Figure 4 and do the following:

1. Turn the rotary switch to DCV or ACV.

2. Insert the red test lead into the V terminal and the black test lead into the G terminal.
Then carry out the measurement.

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B. Measuring Insulation Resistance

Figure 3. Insulation Resistance Measurement

a.UT501 b.UT502

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Caution

When measuring insulation resistance, please must separate the two test leads.
When performing insulation resistance tests, remove all power from the circuit
to be measured and discharge all the power.
Do not short circuit two test leads under high voltage status.
Do not measure insulation resistance after high voltage output.
Do not carry out measurement when the battery compartment is open.
When the measurement is completed, donít touch the circuit as the circuit has

already stored capacitance, which may cause electric shock.
Don't touch the test leads even after it has been removed from the circuit until
voltages are all released.
Do not carry out measurement when the battery compartment is open.

To measure insulation resistance, set up the Meter as Figure 3 and do the following:

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UT501/UT502 OPERATING MANUAL

Turn the rotary switch to one of these position 250V / 500V / 1000V / 2500V.

1. When performing insulation resistance tests, remove all power from the circuit
to be measured and discharge all the power.

2. Insert the red test lead into the LINE terminal and the black test lead into
EARTH terminal.

3. Connect the red and black alligator clip to the circuit to be measured, positive
voltage output from LINE terminal.
Continuous Measurement

1. Turn the rotary switch to one of these position 250V / 500V / 1000V / 2500V

2. Press TEST to button to carry out continuous measurement. Output insulation
resistance testing voltage, TEST button light up,

3. Press TEST button to close the insulation resistance measurement voltage
when measurement is completed. TEST button lights off.

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UT501/UT502 OPERATING MANUAL

Maintenance

This section provides basic maintenance information including battery replacement
instruction.
Warning

Do not attempt to repair or service your Meter unless you are qualified to do
so and have the relevant calibration, performance test, and service information.

A. General Service

Periodically wipe the case with a damp cloth and mild detergent. Do not use
abrasives or solvents.
To clean the terminals with cotton bar with detergent, as dirt or moisture in
the terminals can affect readings.

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UT501/UT502 OPERATING MANUAL

Turn the Meter to OFF when it is not in use.
Take out the battery when it is not using for a long time.
Do not use or store the Meter in a place of humidity, high temperature,
explosive, inflammable and strong magnetic field.
If the Meter is wet, dry it before use.

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B. Replacing the Battery

Figure 4. Battery Replacement

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UT501/UT502 OPERATING MANUAL

Caution
Donít mix to use old and new batteries.
Be careful the polarity is correct when installing batteries.

Danger
Make sure the battery compartment is closed before using the Meter

Follow Figure 4 and proceed as follows to replace the battery:
Turn the Meter to OFF and remove all connections from the terminals.
Remove the screw from the battery compartment, and separate the battery
compartment from the case bottom.
Replace with 6pcs of new 1.5V (LR14) batteries.
Rejoin the case bottom and battery compartment, and reinstall the screw.

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UT501/UT502 OPERATING MANUAL

Specifications

Safety and Compliances

IEC 61010 -1 CA T.II 1000V , CAT.III 600V
overvoltage and double insulation
standard

Certification

Compliances

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Physical Specifications

Display (LCD)
Operating Temperature
Storage Temperature
Relative Humidity

Battery Type
Dimensions (H x W x L)
Weight

Digital: 1999 counts
0 ~35 (32 ~95 )

-20 ~60 (-4 ~140 )
70% @ 0 ~35 below;
80% @ -20 ~60 :
6pcs of 1.5V (LR14) batteries
150 x 100 x 71 mm
Approx. 0.5kg (including battery)

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UT501/UT502 OPERATING MANUAL

General Specifications

Feature Summary

Bright backlight for clear readings in poorly lighted areas.
The Meter automatically selects best range
Red light will on when exporting high voltage.
Auto release voltage

Display Backlight
Autorange
Warning
Voltage

Over loading

Battery Indicator

UT501:
Display 1 M on insulation resistance range.
Voltage display > 1999, display 1 V.
Overload voltage testing is not allowed in this Meter.
UT502: Display OL when overload testing on every range.
Display .

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UT501/UT502 OPERATING MANUAL

AC Voltage
30V~750V (50/60Hz)

1V

(2%+3)

DC Voltage
30 ~ 1000V

Measurement Range
Resolution
Accuracy

Detailed Accuracy Specifications

Accuracy: ([a% of reading] + [number of least significant digits]), guarantee for 1 year.
Operating temperature: 18 ~28
Relative humidity: 45~75%RH

A. Voltage Measurement

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B. UT501: Insulation Resistance Measurement

Output Voltage

Display Range

Open Circuit Voltage

Test Current
Short Circuit

Accuracy

250V

DC250V 10%

0.9mA~1.1mA @250k

500V

DC500V 10%

0.9mA~1.1mA @500k

1000V

DC1000V 10%

0.9mA~1.1mA @1M

Around less than 1.8 mA

3M to 99M : (3%+5)

100M ~ 2000M : (5%+5)

3M ~2000M
(When around less than 4.3M , test lead
insulation is bad or invalid, buzzer will beeps)

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UT501/UT502 OPERATING MANUAL

UT502: Insulation Resistance Measurement

Output Voltage

Display Range

Open Circuit Voltage

Test Current
Short Circuit

Accuracy

Around less than 1.8 mA

3M to 99.9M : (3%+1)

100M ~ 10G : (5%+1)

10G to 20G : (10%+1)

1000V

5M ~4G

(less than 5M, buzzer beeps

and 0M will be shown)

DC1000V 10%

0.9mA~1.1mA @1M

500V

3M ~2G

(less than 3M, buzzer beeps

and 0M will be shown)

DC500V 10%

0.9mA~1.1mA @500k

2500V

25M ~20G

(less than 25M, buzzer beeps

and 0M will be shown)

DC2500V 10%

0.9mA~1.1mA @2.5M

** END **

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UT501/UT502 OPERATING MANUAL

This operating manual is subject to change without notice.

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