Baldor 15H SERIES 15H, Installation & Operating Manual

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Section 1
General Information
A-6 Appendix MN715
Dynamic Braking (DB) Hardware Continued
RTA Assemblies
RTA assemblies include a dynamic brake transistor and gate driver circuit board
completely assembled and mounted in a NEMA 1 enclosure. Brake resistors are not
included in the RTA assembly. Each RTA assembly is designed to be used with an RGA
dynamic brake resistor assembly. The minimum resistance of the RGA assembly must
be equal to or greater than the minimum resistance specified for the RTA assembly.
Select the RTA based on the voltage rating of the control and HP which provides the
dynamic brake watt capacity required. Use Table A-4 to select the RTA assembly.
Refer to Section 3 “Optional Dynamic Brake Hardware” for wiring diagram.
Table A-4 Dynamic Braking Transistor Assemblies (RTA)
HP MAXIMUM BRAKING TORQUE IN % OF MOTOR RATING
208 - 230 VAC 380 - 480 VAC 550 - 600 VAC
20 150% 150% 150% 150% 150% 150% 150% 150% 150% 150%
25 125% 150% 150% 150% 150% 150% 150% 150% 150% 150%
30 100% 150% 150% 120% 150% 150% 150% 150% 150% 150%
40 75% 115% 150% 90% 150% 150% 150% 127% 150% 150%
50 62% 92% 150% 72% 150% 150% 150% 100% 150% 150%
60 60% 150% 150% 150% 85% 145% 150%
75 48% 96% 150% 150% 68% 116% 150%
100 36% 72% 150% 150% 50% 87% 150%
150V 28% 56% 150% 150% 40% 70% 150%
150 48% 126% 150% 34% 58% 150%
200 36% 95% 150% 25% 44% 150%
250 29% 76% 150% 35% 122%
300 62% 125% 29% 100%
350 54% 108% 87%
400 47% 94% 76%
450 41% 84% 68%
CAT. NO. RTA2-6 RTA2-4 RTA2-2 RTA4-20 RTA4-10 RTA4-4 RTA4-2 RTA5-24 RTA5-14 RTA5-4
Minimum
Ohms
6 4 2 20 10 4 2 24 14 4