nord NORDAC PRO SK 511E Series - Reduced Overcurrent Due to Output Frequency; Table 40: Overcurrent Relative to Time

8 Additional information
BU 0505 EN-3021 199
230V devices: Reduced overload capacity (approx.) due to pulse frequency (P504) and time
Pulse frequency
[kHz]
Time [s]
> 600 60 30 20 10 3.5
3...8
110%
150%
170%
180%
180%
200%
10
103%
140%
155%
165%
165%
180%
12 96% 130% 145% 155% 155% 160%
14
90%
120%
135%
145%
145%
150%
16
82%
110%
125%
135%
135%
140%
400V devices: Reduced overload capacity (approx.) due to pulse frequency (P504) and time
Pulse frequency
[kHz]
Time [s]
> 600 60 30 20 10 3.5
3...6
110%
150%
170%
180%
180%
200%
8
100%
135%
150%
160%
160%
165%
10
90%
120%
135%
145%
145%
150%
12
78%
105%
120%
125%
125%
130%
14
67%
92%
104%
110%
110%
115%
16
57%
77%
87%
92%
92%
100%
Table 40: Overcurrent relative to time
Pos: 505 /Anleitungen/ Elektronik/F U und Starter/9. Zusatzinf ormationen [BU 0500 / BU 0200] /Reduzierte Ausgangs leistung/_Reduzi erter Überstro m aufgrund der Ausgangsfr equenz @ 0\mod_13281889346 96_388.docx @ 14351 @ 3 @ 1
8.4.3 Reduced overcurrent due to output frequency
To protect the power unit at low output frequencies (<4.5Hz) a monitoring system is provided, with
which the temperature of the IGBTs (integrated gate bipolar transistor) due to high current is
determined. In order to prevent current being taken off above the limit shown in the diagram, a pulse
switch-off (P537) with a variable limit is introduced. At a standstill, with 6kHz pulse frequency, current
above 1.1x the nominal current cannot be taken off.
x
f( )
In_ 60s ec
f( )
In_ 1sec
f( )
f
0
2 4
6
8 10
12 14
16
18 20
0
0.5
1
1.5
2
2.5
I / I
N
Output frequency [Hz]
Prohibited region
The upper limiting values for the various pulse frequencies can be obtained from the following tables.
In all cases, the value (0.1…1.9) which can be set in parameter P537, is limited to the value stated in
the tables according to the pulse frequency. Values below the limit can be set as required.