3.3 Cautions on Floating Ground Connection
19
IM FG410-01EN
3.3 Cautions on Floating Ground Connection
The signal ground of the BNC terminals for waveform output, sync/sub-output, and external
modulation/addition input, is shared, but since it is insulated from the housing (ground
potential), it can be connected to equipment that have a different potential. Moreover, the
potential has no influence even when the equipment is mounted in a rack.
In the FG420, the above-mentioned BNC terminals are also insulated between channels.
Further, the signal ground of the external 10 MHz frequency reference input is also
insulated from the housing. Therefore, noise caused by ground-loop is not a problem for
connection with a frequency standard. Nor is noise caused by ground-loop a problem in the
case of synchronized connection of multiple units of the FG410 or FG420.
However, in all cases, the floating voltage should be limited to 42 Vpk (DC+AC peak) or
lower to prevent electric shocks.
The other signal grounds are all connected to the housing. The housing itself is connected to
a protective grounding terminal.
WARNING
To prevent electric shocks, do not apply a voltage exceeding 42 Vpk (DC+AC
peak) between the ground of the BNC connectors insulated from the housing
and the housing.
Also, do not apply a voltage exceeding 42 Vpk (DC+AC peak) between the
grounds of the BNC connector groups insulated from the housing. “BNC
connector group,” as used here, refers to multiple BNC connectors that are
connected to a common ground.
If such a voltage were to be applied, the internal voltage limiting elements will
try to curb the working voltage, but if the voltage is too large, equipment
burnout may result.
CAUTION
If there is a difference in potential between the ground of a BNC connector
insulated from the housing and the housing, do not short circuit the hot side of
that BNC connector and the housing, as this may damage the equipment.
CAUTION
If a difference in potential exists between the grounds of the BNC connectors,
do not short circuit these BNC connector grounds, as this may damage the
equipment.
