Owner manual

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
2R6R4R
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