SIEMENS
SINAMICS S150 NEMA
Engineering Information
3
Siemens D21.7
(Part 2) – 2015
Non-inverter duty motors
Motors designed for across the line operation may have an
insulation system per NEMA MG1, part 30 (voltage peaks of
up to 1,000 V with rise times of 2 or more microseconds).
Operating such a motor on a VFD requires the use of an
output filter, to ensure long term reliable operation and
avoid premature insulation failure.
Motor (output) reactor (option L08)
An output reactor limits the rate of rise of voltage (dV/dt) and
helps to avoid damaging bearing currents. An output reactor
does not reduce the magnitude of voltage peaks, irrespective
of cable length. A motor reactor is therefore generally not
adequate for operating non-inverter duty motors on drives.
dV/dt filter with VPL
(option L10)
The dV/dt filter plus VPL (Voltage Peak Limiter) allows the
connection of non-inverter duty motors to the SINAMICS
S150 drive, by limiting the voltage rate of rise dV/dt to
<500 V/µs and voltage peaks as follows:
Max. pulse and output
frequencies (options L08 & L10)
The maximum pulse frequency and output frequency for
SINAMICS S150 with output reactor (option L08) or dV/dt
filter (option L10) are:
Recommended practice
For maximum reliability and equipment life when operating
a motor on a VFD, use:
• An inverter duty motor per NEMA MG1, part 31 with
insulated non-drive end bearing or shaft grounding brush
• A dV/dt filter for a non-inverter duty motor
• Motor cables with a symmetrical design, screened to
minimize EMC issues (PE = ground wire)
• Grounding wires with low impedance across a large
frequency range (DC to 70 MHz) such as braided copper,
terminated with the largest possible surface area
• Separate ground wires connected directly between motor
and drive, and between motor and driven machine
Input and output reactors and filters, harmonics, motor design
3/6
Harmonic feedback to the supply system
The Active Infeed with clean power filter ensure that
SINAMICS S150 drives always meet the harmonic distortion
limits of IEEE 519-1992.
Input power factor
The Active Infeed allows the control of reactive power
absorbed by the drive.
In the factory default setting the drive operates at unity
power factor.
It is however also possible to control the reactive power for
an input power factor in the range of approx. 0.80 leading
to 0.80 lagging.
Motor cable lengths
The cable capacitance of long motor cables causes high
charging currents, and the drives’ ability to cope with these
charging currents may require limits on cable length, and
in some cases the use of an output reactor. SINAMICS S150
technology allows much longer motor cable lengths without
output reactor than older generation products.
Maximum motor cable lengths for SINAMICS S150 without
or with output reactor (option L08) or dV/dt filter (option
L10) are:
Unshielded cable:
1,480 ft (450 m)
Shielded cable:
980 ft (300 m)
If longer cable lengths are required, please consult factory.
Motor design
The switching of IGBTs results in high rates of rise of voltage
(dV/dt) and voltage spikes of up to twice the DC bus voltage
at the motor terminals due to reflections in the cable. Note
that the critical cable length at which voltage doubling
occurs reduces with motor size; for high ratings (150 HP
and up) the critical cable length can be well below 50 ft.
For higher HP drives like SINAMICS S150, the motor cable
length is therefore not a significant factor when considering
the stresses applied to the motor due to voltage rate of rise
and peaks.
Inverter duty motors
Inverter duty motors have an insulation system per NEMA
MG1, part 31 (peaks of 3.1 times the rated voltage with rise
times of
0.1 or more microsecond). They are designed for
the dV/dt and voltage spikes expected with operation on
PWM drives, and generally do not require the drive to be
fitted with an output reactor or filter.
L1
L2
L3
L1
L2
L3
L1
L2
L3
PE
PE
PE
PE
Concentric
Cu or Al screen
Steel reinforcement
G_D011_EN_00065
Rated
Approx. peak voltage
voltage
for motor cable length of
490’ (150 m)
980’ (300 m)
1480‘ (450 m)
380 – 480 V
<1,000 V
<1,000 V
<1,200 V
500 – 600 V
<1,000 V
<1,200 V
1,300 V
Rated
Max. pulse
Max. output
output
frequency
frequency
150 – 400 HP @ 380 – 480 V
4 kHz
150 Hz
All other ratings
2.5 kHz
150 Hz