User`s guide

Installation 2
Series N6700 User’s Guide 43
created by the low side of the scope probe, which is connected to the
load circuit common and also to the scope’s chassis. For this and
similar cases, the following steps by order of preference, will help
mitigate common mode current spikes appearing at the output when
the power system is turned on or off by the AC line switch:
1 Install the ferrite core on the power cord as described under
"Snap-On Core". This inserts impedance in the current path.
2 Install a separate “bonding” wire from the load’s common point,
to the ground terminal of the power system. This provides a
lower impedance path that helps direct injected currents away
from the DC output leads (and the sensitive load).
3 Break the return path through the external equipment. For
example, instead of the single-ended scope shown in the figure,
you can use a differential scope with a floating input or you can
connect an isolated measuring instrument to the load.
NOTE
Disconnecting the load from the output before switching the power system on
or off will always protect the load from common mode currents.
+S
+
-S
+
N6700 Modular
Power System
Scope
probe
1
3
2