GE C70 Instruction Manual page 444

INPUTS/OUTPUTS
5.9.6.3 Application examples
The examples introduced in the earlier Direct Inputs and Outputs section (part of the Product Setup section) are continued
here to illustrate usage of the direct inputs and outputs.
Example 1: Extending input/output capabilities of a UR relay
Consider an application that requires additional quantities of contact inputs or output contacts or lines of programmable
logic that exceed the capabilities of a single UR-series chassis. The problem is solved by adding an extra UR-series IED,
such as the C30, to satisfy the additional inputs/outputs and programmable logic requirements. The figure shows that two
IEDs are connected via single-channel digital communication cards.
Assume that contact input 1 from UR IED 2 is to be used by UR IED 1. The following settings are applied (Direct Input 5 and
bit number 12 are used, as an example).
UR IED 1:
5
DIRECT INPUT 5 DEVICE ID
DIRECT INPUT 5 BIT NUMBER
UR IED 2:
DIRECT OUT 12 OPERAND
The operand of UR IED 2 is now available in UR IED 1 as
Cont Ip 1 On
Example 2: Interlocking busbar protection
A simple interlocking busbar protection scheme can be accomplished by sending a blocking signal from downstream
devices, say 2, 3 and 4, to the upstream device that monitors a single incomer of the busbar, as shown in the figure.
Assume that Phase Instantaneous Overcurrent 1 is used by Devices 2, 3, and 4 to block Device 1. If not blocked, Device 1
trips the bus upon detecting a fault and applying a short coordination time delay.
The following settings are applied (assume Bit 3 is used by all 3 devices to send the blocking signal and Direct Inputs 7, 8,
and 9 are used by the receiving device to monitor the three blocking signals).
UR IED 2:
5-278
Figure 5-153: Input and output extension via direct inputs and outputs
= "2"
= "12"
= "Cont Ip 1
On"
Figure 5-154: Sample interlocking busbar protection scheme
C70 CAPACITOR BANK PROTECTION AND CONTROL SYSTEM – INSTRUCTION MANUAL
.
DIRECT INPUT 5 ON
CHAPTER 5: SETTINGS