2 and 4.3) and their operation is detailed here, O fig. 4.3 – Rockwell Automation 1395 Digital DC Drive FRN 5-10.10/9.30 User Manual
Page 68
Chapter 4
Hardware Description
125 – 300 HP, 230VAC 250 – 600 HP, 460VAC
4-4
Surge Suppression – Surge Suppressor 1 MOV (Fig. 4.2) protects the
armature power bridge from high voltage line spikes and line surges.
SCR Packaging – In 346 – 980A bridges (125 – 600HP) SCRs are
packaged as individual hockey-puck type SCRs. Two SCRs connected in
antiparallel in one of six legs of the bridge is referred to as an SCR cell.
There are 6 SCR cells per bridge for armature regenerative construction.
The non-regenerative version has 6 SCRs only. There are no reversing
SCRs (1R through 6R).
SCR Cell Snubbers – Each SCR cell is protected from rapid rate of
voltage change (dv/dt) using a resistor and capacitor network (referred to
as a Cell Snubber) connected in parallel with the SCR cell.
Figure 4.3
Armature Regenerative Bridge Components (Output)
AB0444A
PP1
PP2
PP3
F12
F11
F10
Snubber
Type 1
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
S
N
U
B
B
E
R
1F
3F
5F
2R
6R
4R
4F
6F
2F
1R
3R
5R
F9
F8
F7
FS1
FS2
FS3
A2
A2
A1
A1
M1
To
Feedback
Board
To
Feedback
Board
To
Pulse Transformer
Board A4
To
Pulse Transformer
Board A3
To
Pulse Transformer
Board A2