Configuration Manual Synchronous Motors 1FT6 - Siemens ...

1.6 Armature short-circuit braking
Definition as described in the Configuration Manual "General Section".
Dimensioning the braking resistors for optimum short-circuit braking
Non-ventilated
Motor Description
1.6 Armature short-circuit braking
The correct dimensioning ensures an optimum braking time. The braking torques which are
obtained are also listed in the tables. Data apply for braking from the rated speed and
moment of inertia Jexternal = Jmot. If the motor brakes from another speed, then the braking
time cannot be linearly reduced. However, longer braking times cannot occur if the speed at
the start of braking is less than the rated speed.
The data in the following table is calculated for rated values according to the data sheet. The
variance during production as well as iron saturation have not been taken into account here.
Higher currents and torques can occur than those calculated as a result of the saturation.
The ratings of the resistors must match the particular I 2 t load capability, refer to the
Configuration Manual "General Section for Synchronous Motors".
Table 1-3 Resistor braking for the 1FT6 series, shaft heights 28 to 48, non-ventilated
Motor type Braking
resistor
external
Ropt [Ω]
SH 28, SH 36, SH 48, non-ventilated
Average braking torque
without
external
braking resistor
Mbr rms [Nm]
with
external
braking resistor
Max.
braking torque
Mbr max [Nm]
rms braking current
without
external
braking resistor
Ibr rms [A]
with
external
braking resistor
1FT6021-6AK7⃞ – 1.1 – 1.6 6.8 –
1FT6024-6AK7⃞ – 2.7 – 3.7 8.3 –
1FT6031-4AK7⃞ 4.4 2.1 2.3 2.8 6.9 6.4
1FT6034-4AK7⃞ 3.7 3.6 4.4 5.5 13 12
1FT6041-4AF7⃞ 0.31 6.7 6.8 8.4 10 10
1FT6041-4AK7⃞ 2.6 5.8 6.8 8.4 18 17
1FT6044-4AF7⃞ 2.0 13 14 17 18 17
1FT6044-4AK7⃞ 1.8 10 14 17 37 33
1FT6 synchronous motors
Configuration Manual, (PFT6), Edition 12.2004, 6SN1197-0AD12-0BP0 1-15