Siemens MICROMASTER 411 - Manual (Page 136)

10 Engineering Information Issue 03/01
MICROMASTER 411 & COMBIMASTER 411 Operating Instructions
136 6SE6400-5CA00-0BP0
10.4.3 Derating with Switching Frequency
The default switching frequency of the MICROMASTER 411/COMBIMASTER 411
is 4 kHz. This is usually adequate for most applications and will allow full
performance to be obtained from all products over the full temperature range.
Select the switching frequency using P1800. High voltage units are automatically
derated by reducing the continuous output current if switching frequencies above 4
kHz are selected. Deratings are shown at P1800 in the System Parameter list.
The switching frequency will be automatically reduced if the internal temperature of
the inverter becomes too high (see r0037, inverter temperature). This reduces
losses and allows continued operation. This feature is controlled by P0290.
Under extreme conditions of overload, the switching frequency may momentarily
reduce to protect the inverter.
Derating applies to constant torque and variable torque settings. Table 10-3 on
page 136 shows the value to which the maximum outputs are reduced.
Table 10-3 Derating with Switching Frequencies
Measured Output Current Power
kW (hp)
4 kHz 6 kHz 8 kHz 10 kHz 12 kHz 14 kHz 16 kHz
0,37
(0,5)
1.2 1.2 1.2 1.2 1.2 1.2 1.2
0,55
(0,75)
1.6 1.6 1.6 1.6 1.6 1.6 1.2
0,75
(1,0)
2.1 2.1 2.1 2.1 1.8 1.8 1.2
1,10
(1,5)
3.0 3.0 2.7 2.7 1.8 1.8 1.2
1,50
(2,0)
4.0 4.0 2.7 2.7 1.8 1.8 1.2
2,20
(3,0)
5.9 5.9 5.1 5.1 3.5 3.5 2.3
3,00
(4,0)
7.7 7.7 5.1 5.1 3.5 3.5 2.3
10.4.4 Derating for Inverter Orientation
The inverter must not be mounted in an upside down orientation. Other mounting
orientations are possible without derating.