Emerson Unidrive HS71 - Page 68

68 Unidrive M / HS Frame 7 to 10 Power Installation Guide
Issue Number: 5
*Resistor tolerance: ±10 %.
The minimum resistance specified are for stand-alone drive systems only. If the drive is to be used as
part of a common DC bus system different values may be required. Contact the supplier of the drive
for more information.
For high-inertia loads or under continuous braking, the continuous power dissipated in the braking
resistor may be as high as the power rating of the drive. The total energy dissipated in the braking
resistor is dependent on the amount of energy to be extracted from the load.
The instantaneous power rating refers to the short-term maximum power dissipated during the on
intervals of the pulse width modulated braking control cycle. The braking resistor must be able to
withstand this dissipation for short intervals (milliseconds). Higher resistance values require
proportionately lower instantaneous power ratings.
In most applications, braking occurs only occasionally. This allows the continuous power rating of the
braking resistor to be much lower than the power rating of the drive. It is therefore essential that the
instantaneous power rating and energy rating of the braking resistor are sufficient for the most
extreme braking duty that is likely to be encountered.
Optimization of the braking resistor requires careful consideration of the braking duty.
Select a value of resistance for the braking resistor that is not less than the specified minimum
09402000 (9E) 2.6 260 90
09402240 (9E) 2.6 260 110
10402700 3.1 218.1 132
10403200 3.1 218.1 160
575 V
07500440 11 87.4 30
07500550 11 87.4 37
08500630 5.5 174.8 45
08500860 5.5 174.8 55
09501040 (9A) 5.1 188.5 75
09501310 (9A) 5.1 188.5 90
09501040 (9E) 3.3 291.3 75
09501310 (9E) 3.3 291.3 90
10501520 3.3 291.3 110
10501900 3.3 291.3 132
690 V
07600190 13 107.3 15
07600240 13 107.3 18.5
07600290 13 107.3 22
07600380 13 107.3 30
07600440 13 107.3 37
07600540 13 107.3 45
08600630 5.5 253.5 55
08600860 5.5 253.5 75
09601040 (9A) 6.5 214.5 90
09601310 (9A) 6.5 214.5 110
09601040 (9E) 4.2 331.9 90
09601310 (9E) 4.2 331.9 110
10601500 4.2 331.9 132
10601780 3.8 366.8 160
Model
Minimum resistance
*
Instantaneous power rating Continuous power rating
Ω kW kW
Unidrive M frame7 to 10 Power Installation Guide issue5.book Page 68 Tuesday, May 24, 2016 11:52 AM