Understanding The Gn610 And Gn611 Input - HBM Genesis GEN5i User Manual

I2679-4.0 en
Using the above table one can deduct that this specification informs the user
the device passed the insulation tests; 5 sec at 2.210 V RMS and impulse
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.
12.2.5

Understanding the GN610 and GN611 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 with the only
difference being an opposite polarity or sign. Below you can find a (simplified)
schematic representation of the input channel of the GN610.
The input channels of the GN610 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:
The Resistance/Capacitance from each terminal to ground is identical.
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Both terminals have isolated connectors (i.e. isolated from system ground).
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The isolated ground is not externally accessible as shown in Figure 12.5.
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Figure 12.5: 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 down.
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