Getting Started 1
Keysight U3401A User’s and Service Guide 31
The terminals at a glance
Figure 1-8 Input terminals
To avoid damaging this multimeter, do not exceed the rated input limit.
Voltages above 300 VAC may be measured only in circuits that are isolated from
mains. However, transient overvoltages are also present on circuits that are
isolated from mains. The Keysight U3401A is designed to safely withstand
occasional transient overvoltages up to 2500 V PEAK. Do not use this
multimeter to measure circuits where transient overvoltages could exceed this
level.