Danfoss VLT AutomationDrive FC 300 Design Manual page 42

3. Introduction to FC 300
200-240 V
PK25-P11K
P15K-P37K
380-500 V
PK37-P75K
P90K-P160
3
P200
P250-P400
525-600 V
PK75-P75K
525-690 V
P110-P315
P355-P560
Table 3.3: Braking at high overload torque level
1) 355 kW at 90% torque. At 100% torque the braking duty cycle is 13%. At mains rating 441-500 V 100% torque the braking duty cycle is 17%
400 kW at 80% torque. At 100% torque the braking duty cycle is 8%
2) Based on 300 second cycle:
For 355 kW the torque is 145%
For 400 kW the torque is 130%
3) 500 kW at 80% torque
560 kW at 71% torque
4) Based on 300 second cycle:
For 500 kW the torque is 128%
For 560 kW the torque is 114%
Danfoss offers brake resistors with duty cycle of 5%, 10% and 40%. If a 10% duty cycle is applied, the brake resistors are able to absorb brake power
for 10% of the cycle time. The remaining 90% of the cycle time will be used on dissipating excess heat.
The max. permissible load on the brake resistor is stated as a peak power at a given intermittent duty cycle and can be calculated as:
The brake resistance is calculated as shown:
As can be seen, the brake resistance depends on the intermediate circuit voltage (U
The FC 301 and FC 302 brake function is settled in 4 areas of mains:
Size
FC 301 / 302 3 x 200-240 V
FC 301 3 x 380-480 V
FC 302 3 x 380-500 V*
FC 302 3 x 525-600 V
FC 302 3 x 525-690 V
* Power size dependent
NB!
Check that the brake resistor can cope with a voltage of 410 V, 820 V, 850 V, 975 V or 1130 V - unless Danfoss brake resistors are
used.
42
Cycle time (s)
120
300
120
600
600
600
120
600
600
Brake active
390 V (UDC)
778 V
810 V/ 795 V
943 V
1084 V
MG.33.BA.02 - VLT ® is a registered Danfoss trademark
Braking duty cycle at 100% Braking duty cycle at over torque
torque (150/160%)
Continuous 40%
10% 10%
Continuous 40%
Continuous 10%
40% 10%
1)
40% 10%
Continuous 40%
40% 10%
3)
40% 10%
2
U dc
R br
Ω =
P peak
where
P = P x M x η x η
peak motor br motor VLT
).
dc
Warning before cut out
405 V
810 V
840 V/ 820 V
965 V
1109 V
FC 300 Design Guide
2)
4)
[W]
Cut out (trip)
410 V
820 V
850 V/ 855 V
975 V
1130 V