User Manual
testo 745 · Non-contact voltage tester
Instruction manual [en]
0970 7450 de en 01
Overview
Instrument
1 Test tips for voltage testing
2 Voltage indicator (LED red)
3 On/Off key, change sensitivity
4 Measuring point illumination key
5 Battery compartment cap
6 Handle
7 Measuring point illumination
(LED white)
Explanation of icons
Caution! Warning about a
danger spot, refer to instruc-
tion manual
Conformity mark, verifies
compliance with the valid
EU Directives: EMC Directive
(2014/30/EU) with the stand-
ard EN 61326-1, Low-Voltage
Directive (2014/35/EU) with
the standard EN 61010-1
Caution! Dangerous voltage,
risk of electric shock
Continuous double or
reinforced insulation in
accordance with Category II
DIN EN 61140
The instrument complies with
the WEEE Directive (2012/19/
EU)
Observe prior to use!
• The instruction manual contains information and instructions which are necessary for
operating and using the instrument safely. Before using the instrument, read the instruction
manual carefully and comply with all aspects of it. Keep this document to hand so that you
can refer to it when necessary. Forward this documentation to any subsequent users of the
instrument.
• If the manual is not followed, or if you fail to observe the warnings and instructions, there is
a risk of fatal injury to the user and damage to the instrument.
Safety instructions
• The instrument may only be used by trained personnel. During all operations, please
observe the Employers' Liability Insurance Association provisions for health and safety at
work.
• In order to prevent electric shock, take safety precautions when working with voltages
greater than 120 V (60 V) DC or 50 V (25 V) rms. AC. These values are the limit for contact
voltages in accordance with DIN VDE (values in brackets apply to restricted areas, for
example agricultural sectors).
• The instrument may only be touched at the designated grip areas, the display elements
must not be covered.
• Maintenance work that is not described in this documentation must only be carried out by
trained service technicians.
• If the instrument is modified in any way, operational safety can no longer be guaranteed.
• If there is any battery leakage, the instrument must no longer be used until it has been
checked by our Customer Service.
• The battery acid (electrolyte) is highly alkaline and electrically conductive. Risk of acid burn!
If the battery acid comes into contact with your skin or clothing, thoroughly rinse the areas
affected immediately with plenty of water. If battery acid gets into your eyes, rinse them
immediately with plenty of water and seek medical advice.
Intended use
The instrument may only be used under the conditions and for the purpose for which it was
designed:
• Testing the voltage at insulated cables (non-contact, with no direct galvanic contact) in the
12 to 1000 V range
• Checking cable breakage
• Phase testing at sockets
• The instrument may only be used within the specified measuring ranges and in low-voltage
installations of up to 1000 V (measuring range category CAT IV 1000)
The instrument must not be used for the following:
• To verify that no voltages are present: only use two-pole voltage testers in accordance with
EN 61243-3 to verify that no voltages are present!
• In potentially explosive environments: the instrument is not explosion-proof!
• When it rains: risk of electric shock!
Technical data
Specifications valid at 23 °C ± 5 °C, < 80 % relative humidity:
Feature Value
Voltage indicator Red LED and buzzer
Sensitivities 50 to 1000 V (standard setting)
12 to 50 V (high sensitivity, also displays voltages of 50 to 1000 V)
Frequency range 40 to 400 Hz
Temperature range Operation: -10 to 50 °C
Storage: -15 to 60 °C
Relative humidity < 80 %
Height < 2000 m
Batteries 2x 1.5 V IEC LR03 (AAA)
Power consumption Approx. 80 mA
Dimensions (WxHxD) Approx. 155 x 25 x 23 mm
Weight Approx. 55 g
Standards EN 61326-1, EN 61010-1
Protection class IP 67 (IEC 60529)
Authorizations CE
Warranty Duration: 2 years
Terms of warranty: see website www.testo.com/warranty
Operating the instrument
Switching the instrument on
> Briefly press the On/Off key.
- After switching it on, the test range 50 V - 1000 V is set.
> Briefly press the On/Off key to change the sensitivity range.
Within the 12 - 50 V range, voltages between 50 V and 1000 V are also displayed. If a voltage
in excess of 50 V is near a voltage between 12 V and 50 V, the higher voltage might be dis-
played.
- The slowly flashing red LED indicates that the instrument is ready: single flash within the
sensitivity range 50 V - 1000 V, double flash within the sensitivity range 12 - 50 V.
Measuring point illumination
> Press the measuring point illumination key.
- The illumination remains on as long as the key is pressed.
Switching the instrument off
> Press and hold down the On/Off key.
Automatic switch-off: if no button is pressed for approx. 3 minutes, the instrument switches off
automatically.
Carrying out a test
Preparing the voltage test
Prior to every test, please ensure that the instrument is in perfect condition:
• For example, keep an eye out for a broken housing or leaking batteries.
• Check that the instrument is functioning properly (for example at a known voltage source)
before and after every test.
• If the safety of the user cannot be guaranteed, switch off the instrument and secure it to
prevent unintentional usage.
Carrying out a voltage test
When carrying out the test, please note:
• The signal during the voltage test does not provide any information about the type or level
of the voltage being applied.
• The location of the earth conductor in the test object may affect the readings.
• The instrument has a complex digital filter for eliminating interference due to high-frequency
electrical fields (for example from computers or fluorescent tube starters). Nevertheless,
incorrect readings may occur in the vicinity of such sources of interference.
> Move the instrument slowly along the test object, for example a cable.
- When the instrument detects an AC voltage in the range 12 - 50 V, the red LED flashes and
the buzzer emits a signal.
- When the instrument detects an AC voltage in the range 50 V - 1000 V, the red LED is per-
manently on and the buzzer emits a signal.
Service and maintenance
Changing the battery
When the red LED is permanently on with no audio signal, the batteries need to be changed.
Change the batteries without delay, because reliable readings can no longer be guaranteed.
> Open the battery compartment: undo the screw and remove the battery compartment cap.
> Remove the spent batteries.
> Insert new batteries in accordance with the battery icon.
> Close the battery compartment: put the battery compartment cap on and tighten the screw.
Maintenance
When operated in accordance with the instruction manual, the instrument does not require any
particular maintenance.
Storage
> If the instrument is not in use for a significant period of time: remove the batteries in order to
prevent any danger or damage due to any potential leaking of the batteries.
Cleaning
Prior to cleaning, the instrument must be disconnected from all measuring circuits.
> Wipe the instrument with a damp cloth and a small amount of mild household detergent.
Never use any harsh cleaning agents or solvents to clean the instrument! After being cleaned,
the instrument must not be used until it has completely dried.
Protecting the environment
> Dispose of faulty rechargeable batteries/spent batteries in accordance with the valid legal
specifications.
> At the end of its useful life, send the product to the separate collection for electric and
electronic devices (observe local regulations) or return the product to Testo for disposal.
www.testo-international.com