Checking The Protective Ground Wires - Sirona Orthophos XG 3 Installation Instructions Manual

6 Safety checks

6.1 Checking the protective ground wires

6.1 Checking the protective ground wires
Measuring setup for protective
ground wire test
DANGER
Shock hazard! It is essential that you switch the X-ray
unit OFF before replacing any components!
If you have not done it already...
Switch OFF the line voltage at the main switch of the
building installation.
Disconnect the power cable and the second protective
ground wire from the building installation.
Remove the following cover parts:
– Profile cover
– Tube assembly cover, front
– Tube assembly cover, rear
60
~
A
Ammeter
Power source
Measuring points B-E
B
C
D
E
Check whether the ground wire resistance complies
with the specifications
Protective ground wire test
between...
A and B
A and C
D
A and
A and E
A power source with a current of at least 0.2 A and a
no-load voltage of 24 V max. and 4 V min. is required.
Connect the power source between the measuring
points specified in the table for at least 5 s and mea -
sure:
– the voltage drop with the voltmeter
– the current with the ammeter and
– calculate the resistance using the formula R = U / I
Sirona Dental Systems GmbH
Installation Instructions ORTHOPHOS XG 3
A
Measuring point
Central ground wire
Voltmeter
V
GNYE wire 0,1Ω
2. Protective 0,1Ω
ground wire
Housing DX32 0,2Ω
Tube assembly 0,2Ω
housing
D 3352.031.03.18.02
60 51 416 D 3352