User manual

14 GMC-I Messtechnik GmbH

5.2 Visual Inspection

Visual inspection is performed prior to measurements with the test instrument.

Visual inspection includes:

• damage to connector cables;

• insulation damage;

• selection and application of conductors and plugs for their intended use;

• condition of mains plug, of connection terminals and wires;

• defects of bending protection;

• defects of connector cable strain relief;

• condition of fastenings, of conductor fixings, of the fuse holder which is accessible to the

user, etc.;

• damage to the housing and protective covers;

• signs of excessive strain or improper use/handling;

• signs of inadmissible tampering or modifications;

• fouling, corrosion or aging to a degree unduly impairing the safety of the instrument;

• fouling and/or clogging of openings for cooling purposes;

• condition of air filters;

• leakproofness of containers for water, air or other agents/fluids, condition of pressure

control valves;

• operation of switches, control and/or setting equipment, etc.;

• legibility of safety labels or symbols, of rated values and position indicators.

5.3 Measuring Protective Conductor Resistance

➭ In the case of instruments equipped with a protective conductor, connect the DUT as de-

scribed in the following picture.

here: dut (Safety class I) and mains plug, also see chapter 4.4, page 11.

➭ Set the measuring function selector switch to the “R

20 Ω” position.

➭ Read the measured value in “Ω” from the LCD

➭ Move the cable from the DUT during the measurement, section by section over its entire

length, in order to locate interruptions.

Protective conductor resistance may not exceed the following values:

To test socket

To housing for measurement of protective conductor resistance