14
Unidrive Regen Installation Guide
www.controltechniques.com
Issue Number: 2
5.9
Fusing
Fusing for the Regen system is required in order to protect the following:
•
Supply transformer
•
Supply cables
•
Regen inductor
•
Regen drive
•
Motoring drive
In the event of failure, the fusing will prevent fire by limiting the amount of energy allowed into the Regen and motoring drive units. The AC supply
fusing should be rated to the Regen system’s continuous rated current. The Regen AC fusing when used with each multiple size 5 Regen drive
should be rated to the 450A continuous rated current of the drive. The +DC bus fusing when used with multiple motoring drives should be rated to 2 x
motoring drive rated current and > 750Vdc.
5.9.1
Standard systems
Fusing for a standard Regen system, single Regen plus single motoring drive (both drives of the same rating) should consist of AC supply fusing as
shown below:
Figure 5-2
Fusing: Standard systems
5.9.2
Multiple size 1 to 4 motoring drives
When a Regen system consists of multiple size 1 to 4 motoring drives, AC supply fusing and +DC bus fusing should be fitted as shown below:
Figure 5-3
Fusing: Multiple size 1 to 4 motoring drives Regen system
Main
Contactor
R
B
Y
3 Phase
Supply
M
AC
Supply
Fusing
Regen
Inductor
Additional
Circuitry
+DC
-DC
+DC
-DC
U
V
W
U
V
W
Regen
Drive
Motoring
Drive
R
B
Y
3 Phase
Supply
M
M
AC
Supply
Fusing
DC Bus
Fusing
Additional
Circuitry
Main
Contactor
Regen
Inductor
+DC
-DC
U
V
W
+DC
-DC
U
V
W
+DC
-DC
U
V
W
Regen
Drive
Motoring
Drive
Motoring
Drive