Rockwell Automation 2090 Ultra3000 Installation Manual - Manual (Page 101)

Publication 2098-IN003E-EN-P — April 2004
Connecting Your Ultra3000 3-5
Single-Phase Power Wired to Single-Phase Drives
The following examples illustrate grounded single-phase power wired
to single-phase Ultra3000 drives when phase-to-phase voltage is
within drive specifications.
Figure 3.4
Single-Phase Grounded Power Configurations
Note: Reducing transformer output will reduce motor speed.
Note: Feeder and branch short circuit protection is not illustrated.
Isolation Transformer in Grounded Power Configurations
When using an isolation transformer, attach a chassis ground wire to
the neutral connection. This accomplishes the following:
• Prevents the system from floating and thereby avoids any high
voltages that might otherwise occur (e.g., through static).
• Provides a solid earth path for fault conditions.
L1
L2
L1
L2 (Neutral)
TB1
L1
L2/N
L1
L2/N
L1
L2/N
E
TB1
L1
L2
L1
L2
L1
L2/N
E
Transformer Secondary
Transformer Secondary
Ultra3000
Single-Phase
TB1 Terminals
AC Line
Filter
Ultra3000
Single-Phase
TB1 Terminals
Bonded cabinet ground bus
AC Line
Filter
Ground grid or
Power distribution ground
Bonded cabinet ground bus
Ground grid or
Power distribution ground
230V ac
Output
115V ac
Output
ATTENTION
!
If the supply transformer is an auto transformer (not
recommended), a chassis earth ground should not be
added.
A chassis earth ground should already be included
elsewhere in the system, and adding another would
create a short.