To final circuits
L N
Tester
(a)
FIGURE 14. important make polarity
test the installation since visual inspection will only indicate conduc-
tor identification. Test separately between the line conductor and earth, and between
the neutral conductor and earth, for every distribution circuit the
consumer’s unit shown Fig.3.Basic Electrical Installation Work
356
should disconnected, since they will respectively glow, charge be
damaged the test.
3.
There are two tests carried out using insulation resistance tester
which must have test voltage 500 d.
4. 14. live and neutral conductors connected together) and the earthing
arrangements may made. 14.70
Insulation resistance test.
To final circuits
L N
Tester
(b)
.70(a).
2. Close all switches and circuit breakers. Remove all lamps. The insulation resistance these tests should
be not less than 1.3.0MΩ for satisfactory result (IEE Regulation 612.
Although insulation resistance reading 1.70(b) and record the result. These are line and neutral conductors earth and between line
conductors. Disconnect appliances.
4.3). Close all switches and circuit breakers.e.
Where the circuit includes electronic equipment which might damaged
by the insulation resistance test, measurement between all live conduc-
tors (i.c.2).0MΩ complies with the
Regulations, the IEE Guidance Notes tell that much higher values than
this can expected and that reading less than 2MΩ might indicate a
latent but not yet visible fault the installation.
2. Record the results a
schedule test results such that given Appendix the IEE
Regulations.
The insulation resistance readings for each test must not less than
1. these cases each circuit
should separately tested obtain reading greater than 2MΩ. Disconnect appliances. for 230 and 400 installa-
tions.
Between line conductors
1.
3.0MΩ (IEE Regulation 612. Test between line and neutral conductors every distribution circuit
at the consumer’s unit shown Fig.
4 Testing polarity (612. Remove all lamps. The procedures are:
Phase and neutral conductors earth
1.6)
The object this test verify that all fuses, circuit breakers and switches
are connected the line live conductor only, and that all socket outlets
are correctly wired and Edison screw-type lampholders have the centre
contact connected the live conductor
