Operating Instructions; Pre-Use Checks; Battery Check; Continuity Testing - Iso-Tech IMT-3300 Bedienungsanleitung

Practical example of single phase RCD test in a TN system.

5 Operating Instructions

5.1 Pre-use checks

 Caution! Before connecting to the circuit to be tested,
carry out the following checks;
5.1.1 Examination
Examine the instrument and test leads before use for any sign
of abnormality, damage or contamination. If any abnormal
conditions exist (i.e. broken test leads, cracked insulation or
case, moisture contamination, display faults or inconsistent
readings etc.) do not use the instrument, but rectify the fault
first. Replace defective leads only with the correct types,
or return the instrument for repair. Contact RS Components
for further advice; the address is given at the end of these
instructions.

5.1.2 Battery check

When the battery voltage falls below 8.0V, the instrument will
not give reliable or accurate indications. Carry out the following
procedure to check there is sufficient energy in the battery
before beginning tests.
a) Remove any leads connected to the instrument.
b) Set the function selector switches to the "Continuity" position.
c) Press the "Press to test" button momentarily to turn the
instrument on.
RCD
Fig 9
— 11 —
d) Check the "low battery "
bottom left corner of the display. If it does, replace the batteries.
5.2 Continuity and Insulation testing
 Warning! Ensure the circuit to be tested is de-energised
before connecting the instrument. Fit safety devices to circuit
breakers or isolators, or remove fuses to prevent re-energising
of the circuit before testing is complete. If the live circuit
indicator illuminates at any time during testing, stop the test
and investigate the cause.
 Warning! The live circuit indicator does not operate when
the "Press to test" button is held or locked down.
5.2.1 Preparation - Continuity and insulation test leads check
a) Slide the test-lead connector cover to expose the continuity
and insulation test connectors.
b) Connect the test leads to the instrument, set the function
switch to the "Continuity" position.
c) Press the test button momentarily and release it. Check the "Ω"
symbol appears in the bottom right corner of the display.
d) Connect the leads together, press and hold down the test
button and ensure the display indicates less than 2Ω and
the buzzer is heard. Check the overrange indicator "OR"
does not appear. Note the reading. If greater than 2Ω is
displayed and the OR indicator appears, the leads may be
open circuit or the fuse may have blown; check and rectify
the cause before proceeding further.
e) Release the test button after the check is complete.

5.2.2. Continuity testing

Note:When carrying out continuity tests, the indicated resistance
includes the resistance of the test leads. Subtract the resistance value
noted at para. 5.2.1 d) above to obtain the actual circuit resistance.
a) Set the function switch to the "Continuity" position.
" indicator does not appear in the