User Manual

Table Of Contents
GMC-I Messtechnik GmbH 17
6.2 3-Phase Measurement (line-to-line voltage) and Phase
Sequence
Connection
The included measure-
ment cables (Z503L) are
required in order to con-
nect the instrument.
Press softkey U3~.
A clockwise phase
sequence is required at all 3-phase electrical outlets.
Measurement instrument connection is usually problematic
with CEE outlets due to contact problems.
Measurements can be executed quickly and reliably without
contact problems with the help of the Z500A variable plug
adapter set available from GMC.
Connection for 3-wire measurement: L1-L2-L3 at plug in
clockwise direction as of PE socket
Direction of rotation is indicated by means of the following dis-
plays:
Note
See section 16 regarding all indications for the mains
connection test.
Voltage polarity
If the installation of single-pole switches to the neutral conductor
is prohibited by the standards, voltage polarity must be tested in
order to assure that all existing single-pole switches are installed
to the phase conductors.
7 Testing RCDs
Testing of residual current devices (RCDs) includes:
Visual inspection
•Testing
Measurement
Use the test instrument for testing and measurement.
Measuring Method
The following must be substantiated by generating a fault current
downstream from the RCD:
That the RCD is tripped no later than upon reaching
its nominal fault current value
That continuously allowable touch voltage value
U
L
agreed upon for the respective system is not exceeded
This is achieved by means of:
Touch voltage measurement,
10 measurements with full-waves and extrapolation of I
N
Substantiation of tripping within 400 ms or 200 ms with I
N
Substantiation of tripping current with rising residual current
This value must be between 50% and 100% of I
N
(usually
about 70%).
No premature tripping with the test instrument, because test-
ing is begun with 30% residual current (if no bias current
occurs within the system)
Clockwise
Counterclockwise
RCD/FI
Table
Differential
Current Waveform
Correct RCD/RCCB Function
Type AC Type A/F
Type B/B+ Type EV/MI
Alternating
current
Suddenly occurring
✔✔✔
Slowly rising
Pulsating
direct current
Suddenly occurring
✔✔
Slowly rising
Direct
current
✔✔
Direct
current
up to 6 mA
I
N
3
--------
I
N
(measurement for up to 1000 ms)
t
a
I
a
t