User Manual
18 GMC-I Messtechnik GmbH
6.2 3-Phase Measurement (line-to-line voltage) and Phase 
Sequence
Connection 
The measuring adapter 
(2-pole) is required in 
order to connect the 
instrument, and can be 
expanded to a 3-pole 
measuring adapter with 
the included measure-
ment cable.
➭ 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 con-
tact problems with the help of the Z500A variable plug adapter 
set available from GMC.
• Connection for 3-wire measurement, plug L1-L2-L3 in clockwise 
direction as of PE socket
Direction of rotation is indicated by means of the following dis-
plays: 
Note
See section 18 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
The 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 nomi-
nal fault current value
• That the continuously allowable contact voltage value U
L
agreed upon for the respective system is not exceeded
This is achieved by means of:
• Contact voltage measurement, 10 measurements with full-
waves and extrapolation of I
ΔN 
• Substantiation of tripping within 400 ms or 200 ms with I
ΔN
• Substantiation of tripping with current rising residual current: 
This value must be between 50% and 100% of I
ΔN
 (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).
* PROFITEST MTECH+, PROFITEST MXTRA & SECULIFE IP
Clockwise
Counter-Clockwise
RCD/FI Table Type of Differential 
Current
Correct RCD/RCCB 
Function
Type AC
Type A, F
Type B*/
B+*
Type 
EV*/MI*
Alternating 
current
Suddenly occurring 
✔✔✔✔
Slowly rising 
Pulsating di-
rect current
Suddenly occurring 
✔✔✔
Slowly rising 
Direct current
✔✔
Direct current 
up to 6 mA
✔
I
ΔN
3
-------
I
ΔN
 (measurement up to 1000 ms)
t
a
I
a
t










