Using the table above, it can be concluded that this specification informs the
user that the device has passed the insulation tests; 5 sec at 2.210 V RMS and
an impulse of 4.000 V. The maximum operating input voltage is 1000 V DC.
This device is to be used to measure CAT II circuitry up to 600 V.
12.2.7
Understanding the GN610/GN611 and GN610B/GN611B input
The signal input channels of the GN610 are of the balanced type. This means
that both inputs within one channel pair are exactly the same. The only
difference is an opposite polarity or sign. A (simplified) schematic
representation of the input channel can be found below.
The input channels are of the isolated type. This means that the input channel
and amplifier are fully isolated from (earth) ground. Fully isolated in this context
means a very high resistance and very small capacitive coupling to ground.
Characteristics per channel:
l
The Resistance/Capacitance from each terminal to ground is identical.
l
Both terminals have isolated connectors (i.e. isolated from system ground).
l
The isolated ground is not externally accessible, as shown in Figure 12.7.
Differential amplifier
+
-
990 kΩ
10
k
Ω
U
iso
U
diff
.
IN(+)
IN(-)
Isolated
channel
Non-isolated
system
990 kΩ
1
0
k
Ω
Figure 12.7:
Isolated balanced input channel
(Not) using probes:
Using passive voltage probes together with balanced isolated inputs is very
difficult and not recommended. The main reason for this is that there is no
ground reference for the probe to divide the input voltage.
GEN3i
220
I3763-3.1 en HBM: public
