Rockwell Automation T80004 Application Note Field Loop Configuration - Manual (Page 45)

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AN-T80004 Field Loop Configuration
Issue 10 Jun 13 AN-T80004 45
Digital Output module to FTA, Standard Cable
The ‘standard’ output cables TC-205, TC-505, TC-207 and TC-507 have power connections at the
chassis end for a T8290 distribution unit. The dual feeds are linked on the block and wired through five
cores to each power group in the module (see page 27). The module switches each load, and the
power to each load is wired to the FTA through the I/O cable. The zero volt return from the load is
wired back to the power supplies through the FTA.
There is no need to wire the five 24V connections of the FTA to 24V if using a standard output I/O
cable. This will only light the FTA LEDs; it does not power the module’s field supply.
The two 24V supplies should be wired through two bridging diodes for each module, each capable of
passing the full current of all the module’s outputs, fitted on heatsinks. If one power supply is shorted,
the diodes will protect the outputs (and the rest of the system) from being shorted.
The module has another connector which provides a zero volt reference for the module’s internal
voltage measurements. This fits on the T8290 unit. Pins 1 and 2 of the centre connector should be
wired to zero volts to provide the reference.
FTA
5 PWR TB 4 3 2 1
Module
0V
6 7 8 9 10
24V A
24V B
High power diodes
to protect against
short circuits
0V (reference)
To Screen Earth
To Safety Earth
To Safety Earth