Testo Testo 755-1 Manual

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Melrose, MA 02176

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Toll Free 1-800-517-8431

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testo 755 · Current/voltage tester

Instruction manual

1 Contents

1 Contents

1 Contents ........................................................................ 2

2 Observe prior to use! ................................................... 3

3 Safety instructions ....................................................... 3

4 Intended use ................................................................. 3

5 Technical data .............................................................. 4

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 measuring point illumination on/off .. 7

7.3. Switching the instrument off ............................. 8

8 Carrying out a test ....................................................... 8

8.1. Preparing the test ............................................. 8

8.2. Voltage testing ................................................. 8

8.3. Single pole phase testing (only testo 755-2) .... 9

8.4. Current measurement ...................................... 9

8.5. Continuity/resistance testing ............................ 9

8.6. Rotating magnetic field direction detection

(only testo 755-2) .................................................... 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

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4 Intended use

2 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.

• Before using the fork meter in places with loud background noise,
make sure that the acoustic signal is discernible.

3 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 70 V (35 V) DC or 33 V (16 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.

• The fork meter must not be used while its battery compartment is open.

• Batteries must be checked before use and changed if necessary.

• 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.

4 Intended use

The instrument may only be used under the conditions and for the purpose
for which it was designed:

• Current measurement, voltage testing in the AC/DC range of
6 to 600 V (testo 755-1) or 6 to 1000 V (testo 755-2), continuity testing /
resistance testing

• Only use the instrument within the specified measuring ranges of the
following overvoltage categories:

- Voltage measurement: CAT IV 600V, CAT III 1000 V

- Current measurement: CAT IV 300V, CAT III 600 V

The instrument must not be used for the following circumstances:

• In potentially explosive atmospheres: the instrument is not explosion­proof!

• When there is rain or other precipitation: risk of electric shock!

3

5 Technical data

5 Technical data

Voltage testing

Figures correspond to +23 °C ± 5 °C at <80% rel. humidity. Temperature
coefficient: 0.15 x specified accuracy per 1 °C (<18 °C and >28 °C).

Feature Values

Voltage range testo 755-1: 6 - 600 V AC/DC

Resolution 0.1 V
Tolerance 6 to 49.9 V: ± (1.5% of the display value + 5

Frequency range DC voltage, 14 Hz – 400 Hz
Acoustic

signalling
Voltage detection Automatic
Polarity detection Automatic
Range detection Automatic
Internal load Approx. 3.5 W at 1000 V
Current Is < 3.5 mA at 1000 V
Operating time 30 s
Recovery time 240 s
Automatic power on > 6 V
Reading memory (HOLD) testo 755-1: 6 - 600 V AC/DC

Overload indicator testo 755-1: > = 630 V AC/DC, LC display

Measurement category CAT III 1000 V / CAT IV 600 V

testo 755-2: 6 - 1000 V AC/DC

digits)
50 to 600 V / 1000 V: ± (1.5% of the display

value + 3 digits)

 50 V AC,  120 V DC

testo 755-2: 6 - 1000 V AC/DC

shows OL
testo 755-2: > = 1050 V AC/DC, LC display

shows OL

Single pole phase testing (only testo 755-2)
Feature Values

Voltage range >90 to 690 V ± 10% AC voltage to earth
Frequency range 50/60 Hz
Acoustic

signalling
LED display Warning symbol

Rotating magnetic field detection (only testo 755-2)
Feature Values

Voltage range 100 to 400 V ± 10% phase to earth/neutral
Frequency range 50/60 Hz
LC display L and R

Yes

4