SIEMENS
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Siemens D 83.1 · 2016
1
Introduction
General technical specifications
Converter operation – General information
■
Overview
Basics
Due to optimized design and manufacturing, most 1PS0 motors
(without explosion protection) and 1PS1, 1PS4, 1PS5, 1MD5
motors (with explosion protection) can also be used for
converter operation without the need to modify the electrical and
mechanical design. The maximum limits and parameters for
converter operation are summarized in this catalog. The special
mechanical characteristics which must be taken into account
that result from the higher speeds are listed below.
Bearing currents
It is known that in motors supplied from the line, a voltage can
form along the mechanical shaft due to magnetic unbalance.
If this shaft voltage exceeds a threshold value of approximately
500 mV, bearing currents that can damage the bearings start to
flow. This phenomenon only occurs with larger motors.
Therefore, to prevent bearing currents, the non-drive end
bearing should be insulated for frame sizes 315 and higher.
However, we recommend that motors of frame size 225 and
above be equipped with insulated bearings on the non-drive
end. The bearing insulation is performed by insulating the
bearing seat on the motor shaft or through the use of current-
insulated rolling-contact bearings. The minimum requirement for
the ordering options is described in detail under "Power tables
for converter operation.”
Converter operation can increase these shaft voltages and
bearing currents (typically by approximately 30 to 50 %).
Additional high-frequency shaft voltages and currents can occur
during operation with pulse converters (common mode bearing
currents and circulating currents). The bearing currents depend
on the motor size and the converter version (clock frequency,
pulse modulation, output filter).
Previous experience shows that drives with SINAMICS G180
pulse converters (clock frequency 3 to 7.5 kHz, pulse
modulation through voltage vector control, standard d
v
/d
t
output
filter) and 1PS0, 1PS1, 1PS4, 1PS5 and 1MD5 motors are not
damaged by the bearing currents that occur.
Mechanical limit speeds
When the motor is operated above its rated frequency, it is
important to note that the maximum speeds are limited by the
limits for the roller bearings, the critical rotor speed and the
rigidity of the rotating parts. In the case of motors for use in
potentially explosive areas of Zone 1 or 2, in accordance with
EN 60079-0, the peripheral speed and therefore the speed of
plastic fans is also limited.
For the limit speeds listed in the tables below, further special
measures may be required.
Mechanical stress and grease lifetime
High speeds that exceed the rated speed with converter
operation and the resulting increased vibrations alter the
mechanical smooth running operation and the bearings are
subject to increased mechanical stress. This reduces the grease
lifetime and the bearing lifetime (please inquire where
applicable).
The use of rigid couplings should be avoided as far as possible.
For converter operation in particular, compliance with the
mechanical limit speeds
n
max
at maximum supply frequency
f
max
is essential, see the following table “Mechanical limit
speeds
n
max
at maximum supply frequency
f
max
.”
We supply SIPLUS CMS Condition Monitoring Systems for
monitoring mechanical components. Servicing procedures are
then easier to plan and execute on time in the context of
preventative maintenance. Order code
Q05
.
Mechanical limit speeds for standard version:
1PS0 and 1PS1 motors without explosion protection and
with type of protection "Non-sparking"
Frame size
No. of poles
2
4
6
8
n
f
n
f
n
f
n
f
rpm
Hz
rpm
Hz
rpm
Hz
rpm
Hz
LOHER VARIO 1PS0 and 1PS1 motors
355
3600
60
2700
90
2400
120
2400
160
400
3000
50
2250
75
2200
110
2100
140
450
3000
50
2100
70
2000
100
1900
127
500
3000
50
1800
60
1600
80
1500
100
Mechanical limit speeds for standard version:
1PS5 motors with type of protection "Ex d"
Frame size
No. of poles
2
4
6
8
n
f
n
f
n
f
n
f
rpm
Hz
rpm
Hz
rpm
Hz
rpm
Hz
LOHER VARIO 1PS5 motors
355
3600
60
2700
90
2400
120
2400
160
400
3000
50
2250
75
2200
110
2100
140
450
3000
50
2100
70
2000
100
1900
127
500
3000
50
1800
60
1600
80
1500
100
SIMOTICS XP 1MD5 and LOHER CHEMSTAR 1PS motors
71
6000
100
4500
150
4000
200
3000
200
80
6000
100
4500
150
4000
200
3000
200
90
6000
100
4500
150
4000
200
3000
200
100
6000
100
4200
140
3600
180
3000
200
112
6000
100
4200
140
3600
180
3000
200
132
5400
90
4200
140
3600
180
3000
200
160
4800
80
4200
140
3600
180
3000
200
180
4600
76
4200
140
3600
180
3000
200
200
4500
75
4200
140
3600
180
3000
200
225
4500
75
4500
150
4400
220
4400
293
250
3900
65
3700
123
3700
185
3700
247
280
3600
60
3000
100
3000
150
3000
200
315
3600
60
2600
87
2600
130
2600
173
355
3600
60
2600
87
2600
130
2600
173
© Siemens AG 2016