Siemens 6RA7086-6KS22

Function descriptions 05.05
9-36 SIEMENS AG 6RX1700-0AD76
SIMOREG DC Master Operating Instructions
Basic tasks for configuring periodic overload operation
Terms: Base-load duty period
300
= min. base-load duty period for 300 s cycle time
Overload period
300
= max. overload period for 300 s cycle time
Basic task 1:
Known quantities: Converter type, cycle time, overload factor, overload period
Quantities to be found: Minimum base-load duty period and maximum base-load current
Solution: Selection of limit characteristic for specified converter type and overload factor
Cycle time < 300s: Overload period
300
= (300s/cycle time) * overload period
Cycle time ≥ 300s: Overload period
300
= Overload period
If: Overload period
300
> overload period
300
for base-load current = 0
Then: Required load cycle cannot be configured,
Otherwise: Determine the maximum base-load current for overload period
300
from the
limit characteristic
Example 1:
Known quantities: 30A/4Q converter; cycle time 113.2s; overload factor = 1.45; overload period = 20s
Quantities to be found: Minimum base-load period and maximum base-load current
Solution: Limit characteristic for 30A/4Q converter, overload factor 1.5
Overload period
300
= (300s/113.2s) * 20s = 53s
Base-load period
300
= 300s – 53s = 247s →
Maximum base-load current = approx. 45% of I
rated
= 13.5A
Basic task 2:
Known quantities: Converter type, cycle time, overload factor, base-load current
Quantities to be found: Minimum base-load period and maximum overload period
Solution: Selection of limit characteristic for specified converter type and overload factor
Determine overload period
300
for base-load current from limit characteristic
Cycle time < 300s:
Max. overload period = (cycle time/300s) * overload period
300
Min. base-load period = cycle time – max. overload period
Cycle time ≥ 300s:
Max. overload period = overload period
300
Min. base-load period = cycle time – max. overload period
Example 2:
Known quantities: 30A/4Q converter; cycle time 140s; current overload factor = 1.15;
base-load current = 0.6*I
rated
= 18A
Quantities to be found: Minimum base-load period and maximum overload period
Solution: Limit characteristic for 30A/4Q converter, overload factor 1.2
Base-load current = 60% of I
rated
→ overload period
300
= 126.35s
Max. overload period = (140s/300s) * 126.35s = approx. 58s
Min. base-load period = 140s – 58s = 82s