GE Industrial Solutions AF-650 GP General Purpose Drive - Manual (Page 16)

6 Calculation of the Brake Resistor
To ensure the optimal choice of the brake resistor for a given application, its inertia and braking profile, some calculations must be carried out.
This chapter (along with examples in the previous) provides guidance through the necessary calculations to determine the values needed for GE to design the
optimal brake resistor for a given application.
6.1.1 Brake Setup
Illustration 7.1 shows a brake set-up using a frequency converter.
The following sections use expressions and abbreviations with respect to a brake set-up that can be seen from illustration 7.1.
h
h
Illustration 6.1: Brake Setup
6.1.2 Calculation of Brake Resistor Values
To keep the frequency converter from cutting out for protection when the motor brakes, the resistor values are to be selected on the basis of the peak braking
power and the intermediate circuit voltage:
Rbr =
Udc 2
Ppeak
Ω
As can be seen, the brake resistor depends on the intermediate circuit voltage (Udc).
Udc is the voltage, where the brake is activated. The Drive-Series brake function is settled in 5 areas of mains:
Size Brake active Warning before cut out Cut out (trip)
AF-650 GP 3 x 200-240 V 390 V 405 V 410 V
AF-650 GP 3 x 380-500 V 810 V 840 V/ 828 V* 855 V
AF-650 GP 3 x 525-600 V 943 V 965 V 975 V
AF-650 GP 3 x 525-690 V 1099 V 1109 V 1130 V
*) 840 V Unit Size 1x, 2x, 3x
828 V Unit Size 4x, 5x, 6x
AF-650 GP Brake Resistor Design Guide
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