8 Part replacement instructions
3.
Measure the protective earth conductor resistance.
a)
For detachable mains power cord:
1.
Stretch the mains power cord to its full length.
2.
Measure the protective earth conductor resistance from end to end, see
figure below:
Figure: Mains power cord earth conductor measurement contacts
NOTICE!
Be careful not to damage the contact with the probe when
connecting it to the unit side plug.
3.
Use opposite polarity of the measuring equipment and measure the
protective earth resistance of the mains power supply cord as described
above.
4.
Flex the mains power cord to different directions and monitor that it does not
cause any variation in the earth conductor resistance.
NOTICE!
If flexing of the mains power cord causes variation to the
earth conductor resistance or if the resistance becomes higher than
measured earlier, replace the mains power cord.
b)
For permanent power supply cord:
1.
Measure protective earth resistance between the protective earth connection
in the mains line and the power supply cord plug (see figure
Mains power
cord earth conductor measurement contacts
).
2.
Use opposite polarity of the measuring equipment and measure the
protective earth resistance of the mains power supply cord as described
above.
3.
Flex the mains power cord to different directions and monitor that it does not
cause any variation in the earth conductor resistance.
NOTICE!
If flexing of the mains power cord causes variation to the
earth conductor resistance or if the resistance becomes higher than
measured earlier, replace the mains power cord.
4.
Check that the earth conductor resistance is less than 100 mΩ.
NOTICE!
If the measurement result is 100 mΩ or higher, replace the mains
power supply cord.
5.
Record the measurement results.
ORTHOPANTOMOGRAPH
™
OP 3D
155
