11
ELECTRICAL CABLES – CONTACTS
9
Test of mains cable
The earth fault breaker does not allow the current to pass this when it is not
connected to the mains supply. In order to check the mains cable with a
multimeter, the earth fault breaker ends must be pulled apart to access the
connection points. Remove the two screws on each end.
Measuring instruments
For the tests below, a multimeter is used that is set for measuring a
broken/closed electric circuit. A closed circuit is normally marked with a
buzzer signal in the multimeter.
The illustrations below show: left illustration one contact point, right
illustration other contact point when measuring.
Cable: contact – earth
fault breaker
Check that the earth cable is
intact.
Cable: contact – earth fault
breaker
Measure between the contact pin and
earth fault breaker's connection point.
Repeat the measurement on the other
pin/connection point (arrows).
Check in a similar way that the earth
cable is intact.
Cable: earth fault breaker –
switch
Measure between the earth fault breaker's
contact points and both switch connec-
tions.
Check that the earth cable is intact. The
earth cable connections are located under
the circuit board.
Cable: earth fault breaker
– switch
Check that the earth cable is
intact.
Circuit breaker
Measure between the switch's incoming
and outgoing contact points. Press the
switch to check that it connects to the
electric circuit.
Circuit breaker
Press the switch to check that it
connects to the electric circuit.
Cable: switch – motor
The measurement method to exclusively check the cable between the switch
and the circuit board is not present as there are no uninsulated areas on the
circuit board. The only way of checking the cable is to measure it in series
with the stator winding which must then be intact. Measure between the
switch and one of the carbon brushes. Resistance measurement gives the
clearest results.
