8 Re-test
8.4 What the test steps involve
Dentsply Sirona
Service Manual CEREC Primescan AC, Primescan AC, CEREC Omnicam AC, Omnicam AC
132
66 81 832 D3696
D3696.076.01.02.02 05.2019
8.4.2
Protective ground wire resistance
The protective ground wire resistance of the power cable (measured
from plug to socket) must be ≤ 100 mΩ.
The protective ground wire resistance between components connected
by the protective ground wire and the protective ground wire connection
to the power socket must ≤ 100 mΩ.
The protective ground wire resistance from the power input of the
acquisition unit CEREC Primescan AC / Primescan AC / CEREC
Omnicam AC / Omnicam AC to the PC rear panel must be ≤ 200 mΩ.
The protective ground wire resistance from the power cable plug to the
PC rear panel must be ≤ 300 mΩ.
8.4.3
Device leakage current
The device leakage current must be measured in relation to the PC rear
panel. In the case of direct measurement under normal conditions it
must be ≤ 0.1 mA. In the case of a first fault (protective ground wire
disconnected), it must be ≤ 0.5 mA.
8.4.4
Insulation resistance
Since the camera is an applied part and does not have a patient
connection, when re-testing is carried out, the insulation resistance is
measured instead of the patient leakage current. An instrument able to
provide a test voltage of 500 VDC must be used to take the
measurement.
The insulation resistance is measured between:
● Protective ground and metal part at the front of the camera lens
In both cases, the insulation resistance must be ≥ 0.1 MΩ.
