ComAp IG-NT User Manual page 71

The value of Min Power PtM is ignored during Warming procedure.
The setpoint is used as a limit for Low power protection: if it becomes active, the load is ramped-down using
setpoint Sync/Load strl: Load ramp, to Min power PtM. After protection becomes inactive, the power
limitation is automatically terminated.
Ishort
If the level set in this setpoint is reached, the GCB is opened with delay defined in Ishort del. Intended for
shortcurrent detection.
Step: 1 % of Nomin current
Range: 100 - 500 % of Nomin current
Protection: BreakerOpen & Cool-down.
Ishort del
Delay for generator shortcurrent protection.
Step: 0,02 s
Range: 0,00 – 10,00 s
Hint:
Ishort del can be set in GenConfig to 0,01 s, but this value is rounded to the proximate controller evaluation
period, which is 0,02 s when the frequency is 50Hz.
2Inom del
IDMT curve shape selection. 2Inom del is the Reaction time of IDMT protection for 200% overcurrent
Igen = 2* Nominal current.
Step: 0,1 s
Range: 0,0 - 60,0 s
Protection: BreakerOpen & Cool-down.
IDMT is inversely proportional to the generators overcurrent. The higher the overcurrent gets the less time
will elapse before the protection is activated.
When the IDMT protection is activated the GCB is opened, the event is recorded in the Alarmlist and History,
and the engine will cool down and stop.
Reaction time =
Where Reaction time is the amount of time from IDMT detection to the opening of the GCB.
Hint:
The maximum allowable Reaction time is 900 sec.
Igen is the maximum current of the three phases of generator current.
EXAMPLE of Reaction time for different over current levels.
Igen [%] <=100
2Inom del
0,1 No action
0,2 No action
0,5 No action
1,0 No action
2,0 No action
5,0 No action
10,0 No action No action
IS-NT-Async-SPI, SW Version 1.2, ©ComAp – February 2011
IS-NT-Async-SPI-1.2.PDF
[ % ]
[ s ]
[ s ]
2Inom del * Nomin current
Igen -
Reaction time is the amount of time from IDMT detection to the opening of the GCB.
101 102
10
20 10
50 25
100 50
200 100
500 250
500
Nomin current
105 110
5 2 1
4 2
10 5
20 10
40 20
100 50
200 100
120 150 200
0,5 0,2 0,1
1 0,4 0,2
2,5 1 0,5
5 2 1
10 4 2
25 10 5
50 20 10
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