Fusing - Control Techniques Unidrive Regen Installation Manual

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
R
3 Phase
Y
Supply
B
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
R
3 Phase
Y
Supply
B
14
AC
Main
Supply
Contactor
Fusing
Additional
Circuitry
AC
Main
Supply
Contactor
Fusing
Additional
Circuitry
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Regen
Inductor
Regen
Drive
U
+DC
V
-DC
W
Regen
Inductor
Regen
Drive
U
+DC
V
-DC
W
Motoring
Drive
U
+DC
M
V
-DC
W
Motoring
Drive
U
+DC
V
-DC
W
DC Bus
Fusing
Motoring
Drive
U
+DC
V
-DC
W
Unidrive Regen Installation Guide
Issue Number: 2
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