It protection – Rockwell Automation 20D PowerFlex 700S AC Drives with Phase II Control Reference Manual User Manual
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Rockwell Automation Publication PFLEX-RM003E-EN-E - January 2011
Chapter 1 Detailed Drive Operation
IT Protection
The drive’s IT protection dictates the amount of overload capacitors and duty
cycle. Ratings are in the tables listed below.
shows expected times.
Figure 16 - IT Curve
Time On (s) = time, in seconds, at current level shown
Time Off (s) = time, in seconds, at 100% current
Duty Cycle% = time on / (time on + time off ) x 100
The On Time/Off Time ratio is fixed. If only 1/2 of the listed time is spent at a
given level, only 1/2 of the off time is necessary to reset the cycle.
Current (%)
Time On (s) Time Off (s)
Duty Cycle (%)
150
3.0
57
5.0
145
3.4
58
5.6
140
3.9
59
6.3
135
4.7
61
7.1
130
5.7
63
8.3
125
7.4
66
10.0
120
10.4
73
12.5
115
17.8
89
16.7
114
20.7
95
17.9
113
24.7
104
19.2
112
3038
117
20.8
111
40.7
138
22.7
110
60.0
180
25.0
109
69.2
180
27.8
108
81.8
180
31.2
107
100.0
180
35.7
106
128.6
180
41.7
105
180.0
180
50.0
104
300.0
180
62.5
103
900.0
180
83.3
102.5
4500000.0
180
100.0
102.5%
104%
106%
108%
110%
112%
114%
120%
130%
140%
150%
10000000.0
1000000.0
100000.0
10000.0
1000.0
100.0
10.0
1.0
Current (%)
Time (sec)