External Components - Emerson Unidrive M700 User Manual

The external user 24 Vdc supply is also required for drive frame sizes 6 and larger for the Power
Stage dependent upon the final DC Bus voltage level. If the DC Bus is below the AC supply loss level
this is required.
For drive frame sizes 9 and larger the external user 24 Vdc supply is also required for the heatsink
cooling fans dependent upon the final DC Bus voltage level. If the DC Bus is below than the AC
supply loss level this is required.
Power Stage external user 24 Vdc supply, drive frame sizes 6 and larger, Low voltage DC mode
External user 24 Vdc supply
Drive model DC Bus (Vdc)
200 Vac Vdc < 205
400 Vac Vdc < 410
575 Vac Vdc < 540
690 Vac Vdc < 540
2.3

External components

The drive in Low voltage DC mode uses external contactors for selection of the power supply, these
power supplies being the AC supply, Low voltage DC supply, UPS supply and External user 24 Vdc
supply.
The external contactors are also required to support the drives seem-less external contactor control
for safe operation from the AC supply to the Low voltage DC supply, refer to System 3 and System 4
in section 6.5 for further details and Pr 06.068, Pr 06.069 and Pr 06.070. During operation in Low
voltage DC mode contactor feedback is required to support the transition between the AC supply and
the Low voltage DC supply by the drive. Alternatively the transition between the AC supply and the
Low voltage DC supply can be managed by the Elevator controller.
NOTE:
It is important to consider pre charging of the drive when applying either the AC or the Low voltage
DC power supplies, and during transitioning between power supplies.
2.3.1 Drive frame sizes 3 to 6
The external contactor control on the drive is setup to control the AC supply contactor for operation
with frame sizes 3 to 6, managing the transition from the AC supply to the Low voltage DC supply.
The inrush from the AC supply and the Low voltage DC supply is managed on the power stage of the
drive with an internal inrush circuit.
During the transition from the Low voltage DC supply back to the AC supply the drives internal soft
start circuit relay must be in circuit (drive in Under Voltage state) drive disabled, to manage the inrush
current for when the AC supply is reapplied.
For operation with a UPS the external contactor control is managed by the Elevator controller to
connect and disconnect both the AC supply and the UPS supply with both of these being
synchronized. The inrush from the AC supply and the UPS supply are managed on the drive with an
internal inrush circuit.
2.3.2 Drive frame sizes 7 and larger
The external contactor control on the drive is setup to control a DC supply contactor for operation with
drive frame sizes 7 and larger, managing the transition from the AC supply to the Low voltage DC
supply. The inrush from the AC supply is managed through the drives half controlled rectifier, the
inrush from a Low voltage DC supply connected directly to the drives DC Bus must be managed with
an external soft start circuit.
During the transition from the Low voltage DC supply back to the AC supply the drives half controlled
rectifier will manage the inrush current when the AC supply is reapplied. The external soft start circuit
is required to manage the inrush current for when the Low voltage DC supply is applied.
P a g e | 8
Connect external user 24 Vdc supply to Power Stage