Siemens SIMOTICS SD User Manual

Limit values for the winding insulation resistance
The following table lists the measuring voltage and limit values for the insulation resistance R
i
.
These values correspond to recommendations provided in IEC60034-27-4.
Table 5-1 Insulation resistance of the winding at 40°C
U
rated

/

V U
meas

/

V R
iC

/

MΩ
U≤1000 500 ≥5
1000≤U≤2500 500, max. 1000 100
2500<U≤5000 1000, max. 2500
5000<U≤12000 2500, max. 5000
U>12000 5000, max. 10000
U
rated
= rated voltage, see the rating plate
U
meas
= DC measuring voltage
R
iC
= minimum insulation resistance up to 40°C winding temperature
Converting to the reference temperature according to IEC60034-27-4
Convert values measured at winding temperatures of 40 to 60 °C to the reference temperature
of 40°C:
R
iC
= R
iT
x K
T
R
iC
= R
i
converted to the reference temperature of 40°C
R
iT
= R
i
at the given winding temperature T in °C
K
T
= temperature correction factor
K
T
= 0,5
40 - T
X
X=1 in the range 10...40 °C
X=17 in the range 40...60 °C
40 = reference temperature in °C
T = measurement/winding temperature in°C
The values apply for the complete winding to ground. Twice the minimum values apply to the
measurement of individual assemblies.
• Dry, new windings have an insulation resistance of between 100...2000MΩ, or possibly
even higher values. An insulation resistance value close to the minimum value could be due
to moisture and/or dirt accumulation. The size of the winding, the rated voltage and other
characteristics in󹪞uence the insulation resistance, and may need to be taken into account
when determining measures.
• Over its operating lifetime, the motor winding insulation resistance can drop due to ambient
and operational in󹪞uences.
– Calculate the critical insulation resistance value depending on the rated voltage by
multiplying the rated voltage (kV) by the speci󹪝c critical resistance value.
– Convert the value for the current winding temperature at the time of measurement, see
above table.
Assembly
5.2Preparing for installation
1LE5, 1PC4 shaft heights 280 ... 355
Operating Instructions, 11/2022, A5E41454666A 53

Siemens SIMOTICS SD Specifications

General

Brand	Siemens
Model	SIMOTICS SD
Category	Engine
Language	English