Rockwell Automation 1395 Digital DC Drive FRN 5-10.10/9.30 - Manual (Page 67)

Chapter 4
Hardware Description
125 – 300 HP, 230VAC 250 – 600HP, 460VAC
4-3
Armature Bridge Components A general description of the components in the armature bridge (Figures
4.2 and 4.3) and their operation is detailed here:
Incoming Device – Either a line choke or an isolation transformer is
required.
Fuses – Fast acting semiconductor fuses are standard on all ratings.
Synchronization – The three-phase input to the drive is tapped and fused
using fuses F1, F2 and F3 (Fig. 4.2) and enters the Feedback Board at AI
TB1-11, 13, and 15. The feedback board scales down the voltage to a
range from 3.4 to 7.0VAC depending on the three-phase incoming line
voltage. The scaled voltage is sent to the Power Stage Interface where it
is used to develop the synchronizing information to be used by the Main
Control Board.
AC Current Feedback – Current Transformers ACT-1, ACT-2 and
ACT-3 are used to provide current feedback information to the Feedback
Board at AITB1 – 5, 6 and 7. The Feedback Board rectifies the
three-phase feedback and scales the DC voltage before being sent to the
Power Stage Interface. The DC voltage representing current feedback is
passed directly through the Power Stage Interface and sent to the Main
Control Board.
Figure 4.2
Armature Bridge Components (Input)
To Feedback Board
To Fig. 4.3.
To Feedback Board
L1
L2
L3
To TB5
see Figure
4.1
Branch Fuses
F3 F2 F1
ACT-1
ACT-2
ACT-3
1
2
3