Operation Manual

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BENNING ST 750 A
19. Technical Terms
Protective measures
The test procedure is based on the existing protective measure of the test sample for which the
efcacy at the respective accessible conductive has to be proven. For the BENNING ST 750A
ApplianceTester,thefollowingclassicationhasbeenmade:
Devices with PE connection (protection class I)
The active parts of the device are protected against direct contact. By connecting the accessible
conductive parts of the housing to the protective conductor, these parts are included in the protec-
tive measures of the system concerning direct contact (fault protection). The fault current is detected
by means of the protective conductor current measurement. The device might also have accessible
conductive parts which are not connected to the protective conductor. The fault current is additional-
ly detected by means of the contact current measurement. The device is provided with a protective
conductor connection (shock-proof plug).
Devices without PE connection (protection class II)
Active parts are isolated by means of reinforced or double insulation (basic insulation and additional
insulation). Thus, the device is protected against direct contact. The device is also protected against
indirect contact, because an insulation fault is all but impossible. However, such devices might be
provided with accessible conductive metal housing parts. Devices of protection class II are equip-
ped with a mains plug without protective conductor.
Devices at safety extra-low voltage circuits (protection class SK III)
Devices of protection class III are connected to safety extra-low voltage circuits (SELV / PELV)
only. Protection against dangerous shock current is ensured by the low voltage and safe isolation
regarding other circuits.
19.1 Technical Terms according to DIN VDE 0701-0702
Repair
Measures taken to restore the nominal condition of the technical means of a system
Modification
Interventioninthedevicewhichisadmissibleaccordingtothemanufacturer'sspecications
Qualified electrician
Aqualiedelectricianissomeonewhoisabletoevaluatethetasksassignedtohim/herduetohis/
her professional education, knowledge and experience as well as to the knowledge of the relevant
provisions and who is able to recognize possible dangers.
Electrotechnically trained person
An electrotechnically trained person is someone who has been informed and instructed (if neces-
sary)bythequaliedelectricianregardingthetasks assigned to him/her and regarding possible
dangers in case of improper behaviour. Moreover, the electrotechnically trained person has been
instructed with regard to the required protection equipment and protective measures.
Competent person
In terms of the German Health and Safety at Work Regulation, a competent person is someone
who has the required expert knowledge for the testing of electrical equipment due to his/her vo-
cational education, professional experience and contemporary occupational activity. According to
theGermantechnicalguidelineforoperationalsafety"Competentpersons–specicrequirements
–electricalhazards" (TRBS 1203, Part 3),thecompetentpersonmusthave nished an electro-
technicalvocationaleducationormusthaveanothersimilarelectrotechnicalqualicationsuitable
for the testing of portable electrical equipment to ensure protection against electrical hazards. The
term professional experience means that the person has at least one year of experience regarding
the installation, assembly or maintenance of electrical equipment and/or systems. For the intended
testing of portable electrical equipment, the competent person must have the required detailed
knowledge of electrical engineering as well as of the relevant electrotechnical regulations and must
regularly update this knowledge. These demands show that safety-related evaluation of portable
electricalequipmentbasicallyrequirestheattributesofaqualiedelectrician.
Test
The test comprises measures for determining and evaluating the actual condition regarding the
safety of the device.
Periodic inspection
A periodic inspection is a test which is carried out in certain time intervals and which is intended for
proving the electrical safety.
Contact current
If someone touches parts of a body of an electrical equipment (device) that are not connected to
theprotectiveconductor,thecontactcurrentisthecurrentowingtoearthviathepersontouching
the device.
Differential current
Vectorialsumofallcurrentowingviatheactiveconductorsattheinput(connection)ofthemains
side
Protective conductor current
SumofthecurrentsowingthroughtheprotectiveconductorofdevicesofprotectionclassI,ifthe
bodies of those devices are insulated to earth
Leakage current
Currentowingtoearthortoanexternalconductivepartviathefaultlessinsulationofadevice
Fault current
Currentowingtoearthortoanexternalconductivepartviathefaultyinsulationofadevice
Alternative leakage current
Currentwhichwouldowthroughtheactiveconductorsofatestsampleandtheprotectiveconduc-
tor or the accessible conductive parts at nominal voltage or at nominal frequency of the test sample.
Note: Please observe the test circuits!
Insulating resistance
Ohmic resistance of the insulation (insulating materials) between conductive parts. Note: Only the
insulating resistance between the active parts and the accessible conductive parts is measured.
Protective conductor resistance
Resistance between a conductive part connected to the protective conductor for protective reasons