Martindale Electric VT25 User manual

VT25 / VT28
VOLTAGE TESTER
Instruction
Manual

ALWAYS READ THESE INSTRUCTIONS
BEFORE PROCEEDING
Thank you for buying one of our products.
For safety and full understanding of its
benets please read this manual before use.
Technical support is available from 01923
441717 and support@martindale-electric.
co.uk.
CONTENTS
1 Safety Information 1
1.1 Meaning of Symbols and Markings 1
1.2 Precautions 2
1.3 Safety Advice 3
2 Introduction 5
2.1 Inspection 5
2.2 Description 5
2.3 Accessories 5
2.4 Battery Installation 5
3 Operation 6
3.1 Description of VT25/VT28 6
Elements and LED Indicators
3.2 Auto-power On/Off 8
3.3 Torch 8
3.4 Low Battery Check 8
3.5 Removable Probe Tip Covers 8
3.6 Operating Duty Ratio 9
3.7 Proving Check 9
3.8 Testing for the Presence of 10
Hazardous Live Voltage
3.9 Interference (Phantom) Voltage 11
3.10 Single Pole Phase Test 11
3.11 Phase Rotation Test 11
3.12 Testing for Continuity 11
3.13 Digital Voltmeter LCD (VT28 only) 12
4 Maintenance 12
4.1 Battery Replacement 12
4.2 Calibration 14
4.3 Cleaning 14
4.4 Repair & Service 14
4.5 Storage Conditions 14
5 Warranty 15
 Specications

1. SAFETY INFORMATION
REMEMBER: SAFETY IS NO ACCIDENT
These instructions contain both information
and warnings that are necessary for the
safe operation and maintenance of this
product. It is recommended that you read
the instructions carefully and ensure that
the contents are fully understood. Failure to
understand and to comply with the warnings
and instructions can result in serious injury,
damage or even death.
Particular attention should be paid to the
Warnings, Precautions and Technical
Specications.
Please keep these instructions for future
reference. Updated instructions and product
information are available at:
www.martindale-electric.co.uk
1.1MeaningofSymbolsandMarkings
 Caution-riskofdanger&referto
instructions
 Caution-riskofelectricshock
Equipment protected by double or
reinforcedinsulation(ClassII)
 Suitableforliveworking
CATII (MeasurementCategoryII)is applicable
to test and measuring equipment connected
directly to utilization points (socket outlets
and similar points) of the low-voltage
MAINS installation.
CATIII(MeasurementCategoryIII)is applicable
to test and measuring equipment connected
to the distribution part of the building’s low-
voltage MAINS installation.
CATIV(MeasurementCategoryIV) is applicable
to test and measuring equipment connected
at the source of the building’s low-voltage
MAINS installation.
For further information on measurement categories
visit www.martindale-electric.co.uk/measurement_
categories.php.
EquipmentcomplieswithrelevantEU
Directives
 Endoflifedisposalofthisequipment
shouldbeinaccordancewithrelevant
EUDirectives
1

1.2Precautions
This product has been designed with your
safety in mind, but please pay attention to
the following warnings and cautions before
use.
Warnings
In order to avoid the danger of electrical
shock, it is important that proper safety
measures are taken when working with
voltages exceeding 30V AC rms, 42V AC
peak or 60V DC.
Where applicable other safety measures
such as the use of protective gloves,
goggles etc. should be employed.
The voltage tester must only be used by a
skilled and competent person who is familiar
with the relevant regulations, the safety risks
involved and the consequent normal safe
working practices.
Before each use the voltage tester should
be examined for damage, cracks, cuts or
scratches to the housing, cable and prods.
The cable has black outer and contrasting
inner insulation, to allow damage to the
cable to be easily identied. If there is any
doubt the voltage tester should not be
used.
Make sure the voltage tester is dry, clean
and free from dust, grease and moisture
while in use to avoid the danger from electric
shock due to surface leakage.
Before and after each use, the voltage tester
must be proven using a suitable proving
device or a known good voltage source. Do
notuse the voltage tester if any expected
LED’s fail to illuminate correctly during
proving.
Testing for a voltage that exceeds the
specied limits of the voltage tester may
damage the voltage indicator and may
expose the operator to a shock hazard.
Always check the voltage indicator’s
specied limits before use.
The voltage tester must only be used in low
voltage systems of CAT IV up to 600V, of
CAT III and CAT II up to 690V, and within the
operating temperature and humidity range
specied.
The specied measurement category means
the voltage tester will be safe to the user if
inadvertently connected to a voltage up to
2

1000V AC/DC to earth on a CAT III or
CAT II installation and 600V AC/DC to earth
on a CAT IV installation. It doesnotmean it
can be used to test for a voltage beyond its
maximum specied limits.
If the probe tip shrouds are not tted, great
care must be taken when testing CAT III
and CAT IV installations to avoid the risk of
shorting high energy circuits and arc ash.
Do not use the voltage tester in damp
conditions.
Do not use the voltage indicator if the battery
casing is not tted.
Always keep your ngers behind the nger
guards. Never touch the exposed metal prod
tips.
The different indicating signals of the voltage
tester (including the ELV limit indication) are
not to be used for measuring purposes.
The voltage tester must not be dismantled
or modied in any way by unauthorized
persons. The safety of the voltage
tester cannot be guaranteed under such
circumstances and it mustnotbeused.
Cautions
Avoid severe mechanical shock or vibration
and extreme temperature.
If the voltage tester has been stored or
transported in temperatures outside its
normal operating range it should be given
sufcient time to stabilise in the environment
where it is to be used. An acclimatisation
time of at least 2 hours is required prior to
operation of the voltage tester.
To avoid possible corrosion from leaking
batteries, remove the batteries if discharged,
or when the unit is not in use for an extended
period.
1.3 Safety Advice
Depending on the internal impedance of
the voltage tester there will be a different
capability of indicating the presence or
absence of operating voltage in case of the
presence of interference voltage.
A voltage tester of relatively low internal
impedance, compared to the reference value
of 100 kΩ, will not indicate all interference
voltages having an original voltage value
above the ELV level. When in contact with
3

the parts to be tested, the voltage tester may
discharge temporarily the interference voltage
to a level below the ELV, but it will be back to
the original value when the voltage tester is
removed.
When the indication “voltage present”
does not appear, it is highly recommended
installing earthing equipment before work.
A voltage tester of relatively high internal
impedance, compared to the reference value
of 100 kΩ, may not permit to clearly indicate
the absence of operating voltage in case of
the presence of interference voltage.
When the indication “voltage present” appears
on a part that is expected to be disconnected
from the installation, it is highly recommended
conrming by another means (e.g. use of
an adequate voltage tester, visual check of
the disconnecting point of the electric circuit,
etc.) that there is no operating voltage on the
part to be tested and to conclude that the
voltage indicated by the voltage tester is an
interference voltage.
A voltage tester declaring two values
of internal impedance has passed a
performance test of managing interference
voltages and is (within technical limits)
able to distinguish operating voltage from
interference voltage and has a means to
directly or indirectly indicate which type of
voltage is present.
4

2. INTRODUCTION
2.1Inspection
Examine the shipping carton for any
sign of damage. Inspect the unit and any
accessories for damage. If there is any
damage then consult your distributor
immediately.
2.2Description
The VT25 and VT28 are voltage testers
used for proving circuits are dead i.e. not
hazardous live. They are constructed in
accordance with the latest safety standards.
The voltage testers have the following
features:
u AC and DC Voltage testing up to 690V
u LCD indication of AC and DC voltage
(VT28 only)
u Continuity test with optical and
acoustical indication up to 500kΩ
uSingle pole phase test
u Phase rotation test
u Auto-power On/Off
u Automatic AC/DC detection
u Bright LED indication
u Indication of voltage above the ELV level
when batteries at
u Ergonomic and robust housing
u Probe-tip protection
uTorch
u Complies with BS EN 61243-3:2014
u Complies with GS38 when probe tip
covers are tted
u Measurement Category CAT IV 600V,
CAT III 1000V
2.3Accessories
u Probe tip covers (tted)
u 2 x 1.5V AAA alkaline batteries
u Instructions
2.4BatteryInstallation
Refer to Section 4.1 (Battery Replacement)
for battery installation instructions.
5

3. OPERATION
3.1DescriptionofVT25/VT28Elements
andLEDIndicators
1 Test probe L1
2 Test probe L2
3Torch
4 Digital Voltmeter LCD (VT28 only)
5Torch button
6 Main body
7 Battery compartment
8 Buzzer
9 ELV warning and single pole test
indicator
10 Continuity indicator
11 Phase rotation indicators
12 Voltage threshold indicators
13 12V and polarity indicators
6

14 Removable probe tip covers
15 Probe tip protective cover
Polarityindicators
When connected to a DC voltage source
either the + or – polarity LED’s 13 will
illuminate dependant on polarity. The
positive probe 2 is on the main body and is
marked with L2 and +.
When connected to an AC voltage source
both the + and – polarity LED’s will
illuminate.
The polarity LED’s will illuminate when the
voltage source is ≥ 12V AC rms or DC.
Voltagethresholdindicators
The voltage threshold LED’s 12 will
illuminate when the magnitude of the voltage
source is at a value approaching or greater
than the corresponding marked voltage.
For example if the voltage source is 55V
AC rms then the 24V and 50V LED’s will
illuminate, if 690V AC rms all voltage
threshold LED’s from 24V to 690V will
illuminate.
ELVwarningandsinglepoletest
indicator
If the batteries are low or exhausted a
hazardous live voltage will not be indicated
by the polarity or voltage threshold LED’s,
but an indication of a voltage above the ELV
limit (50V) will continue to be indicated by
the ELV LED 9.
The ELV LED also indicates the presence of
AC voltage when the unit is used as a single
pole phase detector.
Continuity indicator
The continuity RX LED 10 will illuminate to
indicate continuity of a circuit under test.
7

Buzzer
The buzzer will sound when:
Voltage above the ELV threshold (50V) is
present,
or AC voltage is detected when used as a
single pole phase tester,
or circuit continuity is detected.
3.2 Auto-power On/Off
The voltage tester automatically powers on
when it detects continuity, AC or DC voltage
>10V approx. or a live phase on probe L2
(single pole test).
The voltage tester will automatically power
off 5 seconds after ceasing to detect voltage
or continuity.
3.3Torch
Pressing the torch button 5 will turn on the
torch and power up the voltage tester.
The torch will automatically power off after 10
seconds.
3.4LowBatteryCheck
Before and after each use short the test
probes of the voltage tester together.
On the VT25, check for an audible tone and
a bright RX LED 10 indication.
If there is no audible tone or the RX LED is
faint the batteries need to be replaced (see
section 4.1 Battery Replacement).
On the VT28 if the batteries need replacing
will be displayed in the top left corner of
the LCD.
Do not use the unit if the batteries need
replacing.
3.5RemovableProbeTipCovers
The probes are tted with removable probe
tip covers 14 allowing the probes to comply
with GS38.
Where access to test points may require
extended probe tips, the probe tip covers
may be removed.
Where possible is advisable to keep these
shrouds tted. If removed, great care must be
taken when using the voltage tester on CAT
III and CAT IV installations to avoid the risk of
shorting high energy circuits and arc ash.
8

3.6 Operating Duty Ratio
The voltage tester should be operated (ON)
for a maximum period of 30 seconds. This
should be followed by a recovery period
(OFF) of 4 minutes.
The operating duty ratio is 8 to 1, so if the
voltage tester is only ON for 2 seconds then
the OFF period need only be 16 seconds.
3.7ProvingCheck
Before each use the voltage tester should
be examined for damage, cracks, cuts or
scratches to the housing, cable and prods.
The cable has black outer and contrasting
inner insulation, to allow damage to the
cable to be easily identied. If there is any
doubt the voltage tester should not be
used.
Before and after use, verify the voltage
tester is functioning correctly with a proving
device (PD690, PD700 or PD710 is
recommended), or a known good voltage
source. Donotusethe voltage tester if any
expected voltage indication LED’s fail to
illuminate correctly during proving.
The LED’s that illuminate during proving will
depend on the magnitude of the proving unit
output or the voltage source. See table 1.
Also check the buzzer sounds during
proving.
Table 1.
VT25/
VT28
LED’s
Voltage
source
230V 50Hz
Proving unit type
PD430
PD440
PD690
PD700 PD710
RX Off Off Off Off
ELV On On On On
+12V On On On Only +
or - On*
-12V On On On
24V On On On On
50V On On On On
120V On On On On
230V On On On On
400V Off On On On
690V Off Off On On
*Illumination of the 12V polarity LED’s
depends on the polarity of the connections
to the PD710. Always reverse the
connections to the PD710 to check the other
12V LED.
9

If only the ELV LED illuminates during
proving then check the batteries.
Warning
If the proving device or voltage source
exceeds the specied limits of the voltage
tester the voltage tester may be damaged
and the operator exposed to a shock
hazard. Always check the specication
of the proving device or the voltage
magnitude of the voltage source before
proceeding with a proving check.
During this verication emphasis should
also be placed upon the exing of the
voltage tester’s cable along its length, and
particularly at the entry points to the hand
held elements, to conrm that the cable has
not been fractured.
3.8TestingforthePresenceofHazardous
Live Voltage
Warning
Hold the voltage tester and test prod
behind the nger guards in a manner that
will not obscure the voltage indication
LED’s. Never touch the exposed metal
test prods or any part of the voltage tester
forward of the nger guards while applied
to hazardous voltages.
If testing at locations with high background
noise levels, always determine whether the
buzzer is perceptible before relying solely on
the buzzer indication.
While taking all required safety precautions
connect both test probes to the UUT (Unit or
location under test).
The polarity and voltage level of any voltage
present will be indicated by the illumination
of the voltage tester LED’s (see section 3.1).
The buzzer will also sound if voltage is
present.
Note: The individual LED indications,
including the ELV LED, are not to be used for
measuring purposes.
10

11
3.9Interference(Phantom)Voltage
It is possible for wiring that is ‘dead’ to
indicate the apparent presence of voltage at
power frequency.
If wiring that is live is running in close
proximity to the ‘dead’ wiring being tested,
there can be capacitive or inductive
coupling between the two, thereby causing
interference (phantom) voltage.
Refer to section 1.3 for safety advice
relevant to interference voltage.
3.10SinglePolePhaseTest
Warning
Single pole phase testing is not suitable to
determine if a circuit is not hazardous live.
A double pole voltage test should always be
used for that purpose.
While taking all required safety precautions
connect the positive test probe 2to the
UUT (Unit or location under test).
The phase indicator LED 9 will illuminate
and the buzzer will sound if the presence of
AC voltage >100V is detected.
3.11PhaseRotationTest
While taking all required safety precautions
connect the test probes L1 and L2 to the
phases to be tested.
The phase to phase voltage will be indicated
by the voltage threshold LED’s 12 or for the
VT28 also by the LCD 4.
The direction of the phase rotation will be
indicated by one of the green phase rotation
LED’s 11 marked L (left rotation) and R
(right rotation).
Note: The method of phase sequence
detection relies on capacitive coupling to
earth through the user. If the insulation/
grounding conditions of the installation under
test or user are not satisfactory then the test
results may be impaired.
3.12TestingforContinuity
While taking all required safety precautions
rmly connect both test prods to the UUT
(Unit or location under test).

12
The continuity indicator RX LED 10 will
illuminate and the buzzer will sound to
indicate circuit continuity.
Do not rely solely on the buzzer as an
indication of continuity. Always check the
voltage threshold LED indications as the
buzzer also sounds to indicate the presence
of voltage.
3.13DigitalVoltmeterLCD(VT28only)
While taking all required safety precautions
connect both test probes to the UUT (Unit or
location under test).
Read the measured AC or DC voltage from
the LCD 4.
4. MAINTENANCE
4.1 Battery Replacement
To avoid shock or injury, disconnect the
voltage tester from any external circuits
before proceeding.
(Use diagram to the right as reference for
battery replacement.)
To gain access to the battery compartment,
use a coin or at blade screwdriver to turn the
battery door anti-clockwise until the dots align.
Pull out the battery door.
Fit 2 new 1.5V, AAA alkaline batteries (IEC
LR03, NEDA 24A).
Replace the battery door and turn it clockwise
until the dots align and the door is ush with
the main body.
Note: Do not mix old and new batteries.

13
2
1
3
OPEN
OPEN
Fixed Body
Battery Door

14
4.2PeriodicTesting
To maintain the integrity of the voltage tester,
Martindale Electric recommends that it is
returned at least once a year to verify physical
integrity, electrical specication and insulation
integrity.
Martindale Electric is pleased to offer you
this service. Please contact our Service
Department for details.
Email: [email protected]
Tel: [phone]
4.3 Cleaning
Warning
To reduce the risk of surface leakage,
this instrument must be kept in a clean
condition.
Prior to cleaning, ensure that the instrument
is disconnected from any voltage source.
Wipe the voltage tester with a cloth soaked
with alcohol or mild non-conductive detergent.
Particular attention should be paid to all areas
forward of the nger guards. Do not use
abrasives, abrasive solvents or detergents
which can cause damage to the voltage
tester. Allow the voltage tester to thoroughly
dry before use.
4.4 Repair and Service
There are no user serviceable parts in this
unit. Return to Martindale Electric if faulty.
Our service department will quote promptly
to repair any fault that occurs outside the
guarantee period.
Before the unit is returned, please ensure that
you have checked the unit and batteries.
4.5StorageConditions
The instrument should be kept in cool, dry
conditions and not subjected to shock,
scratching or other damage, prolonged direct
harsh sunlight, extremes of temperature and
in such a manner as to preserve the working
life of the unit. It is strongly advised that the
unit is not kept in a tool box where other tools
may damage it.

5. WARRANTY AND LIMITATION OF
LIABILITY
This Martindale product is warranted
to be free from defects in material and
workmanship under normal use and service.
The warranty period is 2 years and begins
on the date of receipt by the end user. This
warranty extends only to the original buyer
or end-user customer, and does not apply to
fuses, disposable batteries, test leads or to
any product which, in Martindale’s opinion,
has been misused, altered, neglected,
contaminated, or damaged by accident or
abnormal conditions of operation, handling
or storage.
Martindale authorised resellers shall extend
this warranty on new and unused products
to end-user customers only but have no
authority to extend a greater or different
warranty on behalf of Martindale.
Martindale’s warranty obligation is limited,
at Martindale’s option, to refund of the
purchase price, free of charge repair, or
replacement of a defective product which is
returned to Martindale within the warranty
period.
This warranty is the buyer’s sole and
exclusive remedy and is in lieu of all other
warranties, expressed or implied, including
but not limited to any implied warranty of
merchantability or tness for a particular
purpose. Martindale shall not be liable
for any special, indirect, incidental or
consequential damages or losses, including
loss of data, arising from any cause or
theory.
Since some jurisdictions do not allow
limitation of the term of an implied warranty,
or exclusion or limitation of incidental or
consequential damages, the limitations and
exclusions of this warranty may not apply to
every buyer. If any part of any provision of
this warranty is held invalid or unenforceable
by a court or other decision-maker of
competent jurisdiction, such holding will
not affect the validity or enforceability of
any other provision or other part of that
provision.
Nothing in this statement reduces your
statutory rights.
15

16
Specication
VT25/VT28
Voltage Tester
ELECTRICAL
Voltage Detector
Maximum working voltage: 690V DC & AC rms
Nominal voltage threshold indications:
12, 24, 50, 120, 230, 690V AC/DC
Nominal voltage threshold tolerance:
Conforms to BS EN 61243-3:2014
Internal impedance at ELV a.c.: 260kΩ
Polarity indication: from 12V DC/AC rms
Range detection: Automatic
Response time: <1s to 100% of each nominal
voltage
Frequency range: DC, 16 to 400Hz
Test current (In): <3.5mA
Duty ratio: 30s ON (operated) / 240s OFF (recovery)
Overvoltage protection: 690V DC or AC rms
DigitalVoltmeter(VT28only)
Voltage range: 10V to 690V (DC, 16 to 400Hz)
Resolution: 0.1V
Accuracy: ± (3% + 5 digits)
SinglePolePhaseTest
Voltage range: 100 to 690V AC rms
Frequency range: 50 to 60Hz
PhaseRotationTest
Voltage range: 120 to 400V AC rms (phase to earth)
Frequency range: 50 to 60Hz
Continuity
Resistance range: 0 to 500kΩ + 50%
Test current: 3µA
Overvoltage protection: 690V DC or AC rms
ENVIRONMENTAL
Temperature (Operating): -10°C to 55°C
(Storage): -20°C to 70°C, Non condensing
Humidity (Operating & Storage): ≤ 85% R.H
Altitude: up to 2000m
Pollution degree: 2

Specication
VT25/VT28
Voltage Tester
GENERAL
Power: 2 x 1.5V, AAA alkaline batteries (IEC
LR03, NEDA 24A)
Battery consumption: 80mA max.
Dimensions packed: 285 x 72 x 41 mm
Weight packed: approx. 250g
Includes: 2 x 1.5V AAA batteries, 2 x probe tip
covers, instructions
SAFETY
Conforms to BS EN 61243-3, BS EN 61010-1
CAT IV 600V, CAT III 1000V
Class II, double insulation
IP rating: IP64 to BS EN 60529
GS38 compliance (with probe covers tted)
EMC
Conforms to BS EN 61326-1
17

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Martindale Electric Co. Ltd. Metrohm House,
12 Imperial Park, Imperial Way, Watford WD24 4PP, UK.
T: 01923 441717 F: 01923 446900
www.martindale-electric.co.uk
[email protected]
© Martindale Electric Company Ltd. 2021
Registered in England No. 3387451. LITEZ165
Ver. B5.0