28 Hardware description
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Frames R6i and R7i
The DC input terminals are located at the top of the module; the AC output are located at
the bottom. The ZCU-14 control unit is mounted onto the module; the control unit contains
the basic I/Os and slots for optional I/O modules. Other equipment is primarily installed on
separate mounting plates.
DC connection and capacitor charging
The module must be equipped with external DC fuses.
A DC switch/disconnector can be installed if quick isolation of the module from the DC bus
is required.
A capacitor charging circuit must be fitted if:
•
the module is connected to the DC bus through a DC switch/disconnector, or
•
the module is directly connected to the DC bus and the supply unit of the system does
not have a charging capability.
Frame R6i modules ordered with option +F272 have an internal capacitor charging circuit.
Frame R7i modules require, in addition to option +F272, a charging contactor and charging
resistors which must be fitted outside the module. The contactor is controlled by an internal
monitoring board using a voltage of 230 V DC.
Common mode filtering is implemented by running the DC bus through ferrite cores at the
input of the module.