Siemens SIMOTICS XP 1MB 1 Series

Note
Comment to IEEE43
According to IEEE43, also for winding temperatures <40°C, R
i
must be converted over to the
reference temperature of 40°C.
As the minimum values for R
i
apply at 40°C, the required R
i
values are somewhat higher for
winding temperatures below 40°C.
Measuring the polarization index
1. To determine the polarization index, measure the insulation resistances after 1and
10minutes.
2. Express the measured values as a ratio:
Polarization index=R
i

10min
/R
i

1min
Many measuring devices display these values automatically following the measurement.
Measuring the polarization index is not helpful for insulation resistances >5000MΩ, and is
therefore not included in the assessment.
R
i

10min
/R
i1min
Assessment
≥2 Insulation in good condition
<2 Dependent on the complete diagnosis of the insulation
NOTICE
Damage to insulation
If the critical insulation resistance is reached or undershot, this can damage the insulation and
cause voltage 󹪞ashovers.
• Contact the service center (Page12).
• If the measured value is close to the critical value, you must subsequently check the
insulation resistance at shorter intervals.
See also
Insulation resistance and polarization index (Page63)
Limit values of the anti-condensation heating insulation resistance
The insulation resistance of the anti-condensation heating with respect to the machine housing
must not be lower than 1MΩ when measured at 500VDC.
Assembly
5.2Preparing for installation
1MB..1/2/3/4 - shaft heights 63 ... 355
66 Operating Instructions, 11/2023, A5E52779900A