12
tance reading. If an electrical installation is large, its individual
circuit insulation resistances are all effectively connected in par-
allel. so that the total insulation resistance will be lower than
that of each individual circuit. The greater the number of cir-
cuits connected, the lower will be the overall insulation resis-
tance.
7
Preparation for Measurement
7.1 Before testing always check the following:
The ‘battery low’ indicator is not showing.
There is no visual damage to the tester or test leads.
Test Lead Continuity.
Select the continuity function and 20
Ω
range. Short the test
leads together.
An overrange (OR) indication will mean that the leads are
faulty or instrument fuse is blown. (see fuse replacement
section 12).
8
Insulation Resistance Testing
Warning: Insulation tests should be conducted on circuits
that are de-energised. Ensure circuits are not live before
commencing testing.
8.1 Select the required test voltage (250V, 500V or 1000V) by
rotating the function dial.
8.2 Select the required range (20M, 200M, 2000M) by rotating
the range selector.
8.3 Attach the test leads to the instrument and to the circuit to
be tested. If the voltage warning bleeper sounds, do not press
the test button and disconnect the instrument from the circuit.
The circuit is live and should be de-energised before further
testing. The KT35 indicates the presence of external AC voltage
on the LCD by showing a flashing symbol and the actual value
