TESTO 750 User manual

testo 750 · Voltage tester
Instruction manual
99 Washington Street
Melrose, MA 02176
Phone [phone]
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com

1 Contents
2
1Contents
1 Contents........................................................................2
2 Observe prior to use!...................................................3
3 Safety instructions.......................................................3
4 Intended use.................................................................3
5 Technical data ..............................................................4
5.1. Voltage testing .................................................4
5.2. Single-pole phase testing.................................4
5.3. Rotary field direction detection.........................5
5.4. Continuity testing..............................................5
5.5. General technical data.....................................5
6 Overview.......................................................................6
6.1. Display and control elements...........................6
6.2. Explanation of icons.........................................7
7 Operating the instrument ............................................7
7.1. Switching the instrument on.............................7
7.2. Switching the measuring point illumination
on/off (only testo 750-2 / -3)....................................8
8 Carrying out a test .......................................................8
8.1. Preparing the test.............................................8
8.2. Voltage testing .................................................8
8.3. Voltage testing with RCD/FI trip test (only testo
750-2 / -3) ...............................................................9
8.4. Single-pole phase testing.................................9
8.5. Continuity testing..............................................9
8.6. Determining the rotary field direction................9
9 Service and maintenance..........................................10
9.1. Replacing the batteries ..................................10
9.2. Maintenance...................................................10
9.3. Storage ..........................................................10
9.4. Cleaning.........................................................10
10 Protecting the environment.....................................10

4 Intended use
3
2Observe 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.
3Safety 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.
4Intended use
The instrument may only be used under the conditions and for the purpose
for which it was designed:
• Voltage testing, rotary field detection, single-pole phase testing and
continuity testing
• Only variants testo 750-2 and -3: voltage testing with RCD/FI trip test
• The instrument may only be used within the specified measuring
ranges and in low-voltage installations of up to 690 V (measuring range
category CAT III 690)
The instrument must not be used for the following:
• In potentially explosive atmospheres: the instrument is not explosion-
proof!
• When it rains: risk of electric shock!

5 Technical data
4
5Technical data
5.1. Voltage testing
Feature Values
LED display: voltage range 12 - 690 V AC/DC
LED display: voltage values 12V, 24V, 50V, 120V, 230V, 400V, 690V
LED display: tolerances According to EN 61243-3:2011
LCD display (only variant
testo 750-3): voltage range 10 - 690 V AC/DC
LCD display (only variant
testo 750-3): Resolution 1 V
LCD display (only variant
testo 750-3): Tolerance ± (3 % of the display value + 5 digits)
Frequency range DC voltage, 14Hz – 400Hz
Acoustic signalling ≥50 V AC, ≥120 V DC
Voltage detection Automatic
Internal load Approx. 2.4 W at 690V (load buttons not
pressed)
Current Is < 3.5 mA at 690V (load buttons not
pressed)
Connectible load (only testo
750-2 and -3) Approx. 140 W at 690 V (load buttons pressed)
Connectible test load (only
testo 750-2 and -3) < 200mA (load buttons pressed)
Operating time 30 s
Recovery time 240 s
Automatic power on > 10 V
Reading memory
(HOLD) (only testo 750-3) 10 - 690 V AC/DC
Overload indicator (only testo
750-3) ≥720V AC/DC, LCD display shows OL
5.2. Single-pole phase testing
Feature Values
Voltage range 100 - 690 V AC voltage to earth
Frequency range 50/60 Hz
Acoustic
signalling Yes
LED display Red LED

5 Technical data
5
5.3. Rotary field direction detection
Feature Values
Voltage range 170 - 690 V phase-to-phase
Frequency range 50/60 Hz
LED display Green LED
5.4. Continuity testing
Feature Values
Area 0 - 500 kΩ
Tolerances 0 % to +50 %
Test current < 5 μA
Acoustic signalling Yes
LED display Red LED
Overvoltage protection 690 V AC/DC
Automatic power on < 500 kΩ
5.5. General technical data
Feature Values
Operating ambient
temperature -10°C to 50°C
Storage
ambient temperature -15°C to 60°C
Humidity Max. 95 % RH
Operating altitude Up to 2000 m
Measurement category CAT IV 600V, CAT III 690V
Level of contamination 2
Protection class IP 64
Power supply 2 x 1.5V (AAA / IEC LR03)
Power consumption Approximately 60 mA
Battery life More than 10,000 measurements (< 5 s per
measurement)
Dimensions
(H x W x D) Approx. 280 x 78 x 35 mm
Weight Approx. 320 g
Safety standards EN 61243-3:2011, DIN VDE 0682-401:2011,
EN 61326-1:2013, DIN EN 61010-1:2011
Authorizations CE, TÜV GS, CSA
Warranty Duration: 2 years

6 Overview
6
6Overview
6.1. Display and control elements
Product variant shown: testo 750-3
1 Probe tip - (L1)
2 Probe tip + (L2)
3 Measuring point illumination, white LED (only testo 750-2 and -3)
4 LED display
Display Meaning
AC Voltage testing: AC voltage is applied
+ - Voltage testing: DC voltage is applied
L R Voltage testing AC: rotary field direction left or right
Rx Continuity testing: continuity detected
• Safety extra-low voltage exceeded (> 50 V AC /
> 120 V DC)
• Single-pole phase testing (only testo 750-2 / -3):
Phase detected
12, 24 etc. Applied voltage value in V
5 LCD display (only testo 750-3)

7 Operating the instrument
7
6 Control keys:
Key Function
2x (only testo 750-2 / -3) Carry out RCD/FI trip test
HOLD (only testo 750-3) Record reading
(only testo 750-2 / -3) • Switch measuring point illumination
on/off
• Switch LCD display background
illumination on/off (only testo 750-3)
7 Grip area
8 Battery compartment
9 Probe tip protective cap (with storage compartments for probe tip cover
and probe tip extension)
10 GS38 probe tip cover
11 Probe tip extension (diameter 4 mm, screw-on)
6.2. Explanation of icons
Icon Meaning
Caution! Warning about a danger spot, refer to instruction
manual
Caution! Dangerous voltage, risk of electric shock
Continuous double or reinforced insulation in accordance with
Category II DIN EN 61140
Suitable for work on live parts
Conformity mark, verifies compliance with the valid EU
Directives: EMC Directive (2014/30/EU) with the standard
EN 61326-1, Low-Voltage Directive (2014/35/EU) with the
standard EN 61010-1
Fulfils applicable Australian provisions.
The instrument complies with the WEEE Directive
(2012/19/EU)
7Operating the instrument
7.1. Switching the instrument on
> Connect both probe tips or press any button.
- The instrument switches on.
On the testo 750-3, the LCD display is switched on and shows ---.

8 Carrying out a test
8
7.2. Switching the measuring point
illumination on/off (only testo 750-2 / -3)
> To switch on/off: briefly press the button.
The measuring point illumination switches off automatically after 2 minutes.
Only testo 750-3: the background illumination of the LCD display is
switched on/off at the same time as the measuring point illumination.
8Carrying out a test
8.1. Preparing the 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.
• Always carry out a function test before using the voltage tester, see
below.
• 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 function test
> Connect the voltage tester probe tips for 4 seconds and then
disconnect.
- All LEDs should light up. All segments are illuminated on the LCD
display (only testo 750-3).
Removing/installing the probe tip protector/extension
The probe tip protector and extension can be removed/installed as required.
To store these when not in use, we recommend the storage compartments
on the probe tip protective cap.
Attention: Use of the probe tip protector may be required depending on the
national regulations or provisions!
> Probe tip protector: push onto probe tips or pull off.
> Probe tip extension: screw onto probe tips or unscrew.
8.2. Voltage testing
> Connect both probe tips to the test object.
- The voltage tester switches on automatically at a voltage of
approximately 10 V or above.
- The voltage is indicated by LEDs (12 V, 24 V, 50 V, 120 V, 230 V,
400 V and 690 V).
On the testo 750-3, the voltage is also shown on the LCD display.
- In the case of DC voltage, the polarity of the indicated voltage relates
to the voltage tester probe tip.
- Once the safety extra-low voltage (50 V AC / 120 V DC) is reached or
exceeded, an acoustic signal is emitted.
Recording readings (only testo 750-3)
> Once voltage is applied to the measuring instrument, press the HOLD
button.
- A short acoustic signal is emitted and the LCD display shows the
recorded reading.
> To delete the recorded value, press the HOLD button once again.
- A short acoustic signal is emitted.

8 Carrying out a test
9
The recorded value will automatically be deleted after approx. 10 seconds
once voltage is no longer being applied to the probe tips. This is indicated
by a short acoustic signal.
Once the recorded value has been deleted, the LCD display once again
indicates the voltage currently being applied to the probe tips.
The LED voltage display always indicates the voltage currently being
applied in the electrical circuit.
Voltages below approx. 10 V AC/DC cannot be recorded, --- is shown on
the LCD display.
8.3. Voltage testing with RCD/FI trip test (only
testo 750-2 / -3)
For voltage tests in systems with RCD/FI residual current circuit breakers,
these can be tested with a 10 mA or 30 mA nominal current by connecting a
load:
> Test the voltage between L and PE and press both buttons at the
same time.
- The RCD/FI should trip.
8.4. Single-pole phase testing
Single-pole phase testing is possible from AC voltages of approx. 100 V.
During the single-pole phase testing to determine external conductors, the
display function may be impaired, for example due to insulating personal
protective equipment or other insulators.
The single-pole phase testing is not suitable for testing for absence of
voltage. Two-pole voltage testing is required for this.
> Connect the voltage tester probe tip + (L2) to the test object.
- is illuminated to signify the phase testing.
8.5. Continuity testing
✓Disconnect the test circuit/object from the power supply.
✓Conduct a two-pole voltage test on the test object to confirm the
absence of voltage.
> Connect both probe tips to the test object.
- For continuity up to approx. 500 kΩ, Rx is illuminated and an acoustic
signal is emitted.
- The continuity test switches off automatically after 10 seconds if no
continuity is detected. As soon as continuity is detected, the instrument
switches back on automatically.
8.6. Determining the rotary field direction
The rotary field direction detector is always active, Lor Rmay be constantly
illuminated, however the rotary field direction can only be determined in a
three-phase system between the external conductors.
The tester displays the voltage between two external conductors.
1. Connect the probe tip L1 (-) to the presumed phase L1 and the probe
tip L2 (+) to the presumed phase L2.
2. Completely cover the grip area with your hands!
- If Ris constantly illuminated: "right" rotary field.
- If Lis constantly illuminated: "left" rotary field.

10 Protecting the environment
10
Cross-check:
> Repeat the process with switched probe tips.
- The opposite result must be indicated.
9Service and maintenance
9.1. Replacing the batteries
The batteries need to be replaced if, when connecting the probe tips, Rx
does not light up or the battery icon is illuminated on the LCD display (only
testo 750-3).
1. Disconnect the voltage tester completely from the measurement object.
2. Using a screwdriver, unscrew the two metal screws on the battery
compartment until the battery compartment cover can be removed. Do
not unscrew the screws completely.
3. Remove the spent batteries.
4. Insert new batteries, type AAA / IEC LR03 (1.5 V), ensuring correct
polarity.
5. Put the battery compartment cover back on and screw down.
9.2. Maintenance
When operated in accordance with the instruction manual, the instrument
does not require any particular maintenance.
9.3. 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.
9.4. 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.
10 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.

0970 7500 en 01 V01.00
Test Equipment Depot - 800.517.8431
99 Washington Street,Melrose, MA 02176
TestEquipmentDepot.com