
122 Testing
(iv) All switches should be in the off position.
(v) Test between earth and each terminal of the S.P. switch. Correct
polarity is indicated by:
(a) Continuity tester. There should be a zero reading on only
one of the terminals.
(b) Bell tester. The bell rings on only one of the terminals.
Note:
To test the polarity of the E.S. lampholder shown in
Diagram
90,
the switch would have to be closed after its polarity had been checked.
Circuit polarity (sockets)
Procedure
(i) Remove all appliances.
(ii) Test between (L) right-hand pin and the earth. Correct polarity is
indicated as for lighting circuit.
Continuity of protective conductor ...