MI 3394 CE
MultiTester
XA
Instrument operation
13
4.3 Safety checks
At start up and during operation the instrument performs various safety checks to ensure
safety and to prevent any damage. These safety pre-tests are checking for:
Correct input mains voltage
Presence of input PE connection,
Any external voltage against earth on mains test socket
Excessive leakage currents through measuring I/Os,
Too low resistance between L and N of tested device,
Proper operation of safety relevant internal electronic circuits
If a safety check fails, an appropriate warning message will be displayed and safety
measures will be taken. The warnings and safety measures are described in chapter 4.4
Symbols and messages.
4.4 Symbols and messages
Supply voltage warning
Possible causes:
No earth connection.
Instrument is connected to an IT earthing
system. Press
YES
to continue normally or
NO
to continue in a limited mode (measurements are
disabled).
Warning:
The instrument must be earthed properly to work
safely!
Resistance L-
N > 30 kΩ
In pre-test a high input resistance was measured.
Possible causes:
Device under test is not connected or switched
on
Input fuse of device under test is blown.
Select
YES
to proceed with or
NO
to cancel
measurement.
Resistance L-
N < 10 Ω
In pre-test a very low resistance of the device under test
supply input was measured. This can result in a high
current after applying power to the device under test. If
the too high current is only of short duration (caused by
a short inrush current) the test can be performed
otherwise not.
Select
YES
to proceed with or
NO
to cancel
measurement
