GE GFK-0787B user manual Block Output Groups, Output Load Sharing

3

4-Block Output Groups

All four blocks in a group must be either 16-circuit or 32-circuit blocks. In a group, two source-type Genius blocks are connected in parallel on one side of each load, and two sink-type Genius blocks are connected in parallel on the other side.

Bus A Bus C Bus B

Source Blocks
(IC660BBD020
or
IC660BBD024)
A	B

Load

C

Sink Blocks

(IC660BBD022

or

IC660BBD025)

D

There are three busses. One source block and one sink block are connected to either bus A or bus B (see blocks B and D on bus B in the illustration above). The other two blocks are connected to the remaining two busses (A and C above).

The illustration shows just one load for a group of four blocks. However, up to 16 loads could be controlled by the same group of four blocks (using 16-circuit blocks).

When the blocks are configured, each is assigned the same output reference addresses using Logicmaster 90. Then, the blocks are configured for GMR mode using the Genius Hand-held Monitor.

Output circuits that are to be autotested must be able to withstand the On and Off pulse times used by the test. Check each output device's characteristics against the specifications listed on page 8-12 (for 16-point blocks) and page 8-17 (for 32-point blocks) to verify that it can be autotested and/or used in a 4-block output group.

Output Load Sharing

In a 4-block output group, current to output loads is shared. Therefore, it is not possible to be sure exactly how much power is being provided by each block. If 16-circuit blocks in a GMR output group are configured for No Load fault reporting, the minimum connected load that can be used is 100mA. If blocks in a 4-block output group are configured for No Load reporting, a system output No Load fault will only be reported if both of the source blocks or both of the sink blocks report No Load faults.

3-6	GeniustModular Redundancy Flexible Triple Modular Redundant (TMR) System	GFK-0787B
	User's Manual ± March 1995