User Manual
GMC-I Messtechnik GmbH 59
14.6 Residual Voltage Test – Ures Function (PROFITEST MXTRA only)
Applications
The EN 60204 standard specifies that after switching supply 
power off, residual voltage must drop to a value of 60 V or less 
within 5 seconds at all accessible, active components of a 
machine to which a voltage of greater that 60 V is applied during 
operation.
With the PROFITEST MXTRA, testing for the absence of voltage is 
performed as follows by means of a voltage measurement which 
involves measuring discharge time tu: 
In the case of voltage dips of greater than 5% of momentary line 
voltage (within 0.7 seconds), the stopwatch is started and 
momentary undervoltage is displayed as Ures after 5 seconds, 
and indicated by the red UL/RL LED.
The function is ended after 30 seconds, after which Ures and tu 
data can be deleted and the function can thus be restarted by 
pressing the ESC key.
Connection
Limit Values
Setting Limit Values
Measuring Sequence – Long-Term Measurement
Testing is selected as a 
continuous measure-
ment because residual 
voltage testing is trig-
gered automatically and 
voltage measurement is 
always active for safety 
reasons.
Note
If, for example, conductors are exposed when a machine 
is switched off – e.g. if plug connectors are disengaged – 
which are not protected against direct contact, maximum 
allowable discharge time is 1 second!
Limit value:
ΔU % > limit value
U
L
 ⏐ R
L
ΔU










