Rockwell Automation 865 Differential Protection Relay - Manual (Page 72)

3-28 Protection
Functions
865-UM001A-EN-P – July 2009
NOTE: This protection function needs optional hardware in slot X6.
More details of the hardware can be found under “Optional Two-
Channel Arc Protection Card” in Chapter 9, and “Arc Protection
Interface (Option)” in Chapter 10.
Arc protection is used for fast arc protection. The function is based
on simultaneous light and current measurement. Special arc sensors
are used to measure the light of an arc.
Three Stages for Arc Faults
There are three separate stages for the various current inputs:
• ArcI> for phase-to-phase arc faults. Current inputs
IL1, IL2, IL3 are used.
• ArcI’> for phase-to-phase arc faults. Current inputs
I’L1, I’L2, I’L3 are used.
• ArcI
01
> for phase-to-earth arc faults. Current input
I
01
is used.
•
ArcI 02 > for phase-to-earth arc faults. Current input
I
02
is used.
Light Channel Selection
The light information source to the stages can be selected from the
following list.
•
– No sensor selected. The stage will not work.
•
S1 Light sensor S1.
•
S2 Light sensor S2.
•
S1/S2 Either one of the light sensors S1 or S2.
•
BI Binary input of the arc card. 48 Vdc.
•
S1/BI Light sensor S1 or the binary input.
•
S2/BI Light sensor S2 or the binary input.
•
S1/S2/BI Light sensor S1 or S2 or the binary input.
Binary Input
The binary input (BI) on the arc option card (see Chapter 8) can be
used to get the light indication from another relay to build selective
arc protection systems. The BI signal can also be connected to any
of the output relays, BO, indicators etc. offered by the output matrix
(See Chapter 5). BI is a dry input for 48 Vdc signal from binary
outputs of other Allen-Bradley relays or dedicated arc protection
devices by Allen-Bradley.
Arc fault protection
(50ARC/50NARC)
(optional)