Sel SEL-2505 User manual

Date Code 20010214 SEL-2505 Remote I/O Module
SEL-2505 Remote I/O Module
Instruction Manual
The SEL-2505 is a remote I/O module
that has eight contact inputs and eight
contact outputs. The status of these
inputs and outputs are communicated
between the SEL-2505 and host device
using MIRRORED BITS™ communica-
tions over a dedicated fiber-optic port.
Each contact input controls one of the
eight MIRRORED BITS transmit bits,
while each of the eight received
MIRRORED BITS controls a Form C
output contact. Use the transmitted
contact input status for control and
indication of a remote device.
 Communications Ability
helps you simplify and
improve existing or new
installations.
 Add bus protection using
existing relay contact
inputs and outputs.
 Add simple pilot
communications to existing two- or three-terminal line applications.
 Isolate relay and breaker dc supplies for breaker failure trip distribution schemes.
 Replace control wiring to outside cabinets with fiber to reduce dc ground exposure.
 Add local or remote trip and close coil monitoring capabilities.
 Compact Size permits panel-mount replacement of existing auxiliary relays.
 Self-Testing increases reliability of auxiliary relay functions.
 Simple Diagnostics consisting of 22 LEDs that indicate contact input, output, channel, and
device status.
 Fiber Optics and Channel Monitoring increase scheme security.
 Three Models provide a wide range of applicable communication paths: 650 nm multimode
fiber for communications paths ≤500 m, 850 nm multimode fiber for paths ≤15 km, or 1300 nm
single-mode fiber for paths ≤80 km.
 Fast Operating Speed compares with high-speed auxiliary relays.
Features, Benefits, and A lications

2
SEL-2505 Remote I/O Module Date Code 20010214
Product Overview
Product Overview
Figure 1 shows the functional overview of the SEL-2505.
The SEL-2505 is an excellent auxiliary relay or a simple way of
expanding the number of I/O points available in a system of relays. It
is superior to hard-wiring relays together through electromechanical or
static auxiliary relays, because you can now monitor the performance of
the communication channel. In addition, its self-testing ability ensures
prompt notification of any device or communication channel problem.
Figure 1 SEL-2505 Functional Overview.
Wide range
power supply
consumes
less than
5 watts.
Alarm contacts
signal self-test
and communi-
cations channel
status.
Level-sensitive
contact inputs
do not assert
during dc
grounds when
applied to center-
grounded systems.
LEDs indicate
input and output
status, channel
activity, device
status, and
communications
channel health.
Fi er-optic port
provides electrical
isolation. Communi–
cations protocol enhances
data transfer security.
Quick setup.
Rugged and
compact
flush mount
enclosure
withstands
EMI, RFI,
shock, and
vi ration.
Output
contacts
rated for
trip and
close duty.
Each output
contact has
oth "a" and
" " contacts
for flexi ility.
Screw
terminals
accept ring
lugs with
wires up to
#10 AWG.
All terminals
are clearly
num ered.
Large
range for
installing
outdoors.
+85˚C
–40˚C
END
LEFT SIDE
POWER SUPPLY
12345678910 11 12 13 14 15 16 17 18 19 20 21 22 23 24
ALARM IN1 IN2 IN3 IN4 IN5 IN6 IN7 IN8
FRONT
IN1 ENABLE ROK OUT1
IN2
IN3
IN4
IN5
IN6
IN7
IN8
OUT2
OUT3
OUT4
OUT5
OUT6
OUT7
OUT8
TX RX
ALARM LOOP
LAMP
TEST
SEL—2505
REMOTE I/O MODULE
SCHWEITZER
ENGINEERING
LABORATORIES
197-0350
RIGHT SIDE
OUT7 OUT6 OUT5 OUT4 OUT3 OUT2 OUT1OUT8
48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25

3
Date Code 20010214 SEL-2505 Remote I/O Module
Applications
A lications
Figure 2 Channel Interface I/O for elays
Without Native MI O ED BIT Protocol.
Figure 3 Provide Communications-Assisted Tripping
Over Existing Digital Communications Networks.
f
Figure 4 Interface elays with MI O ED BITS to elays Without.
IN
+DC
—DC
SEL-2505 (partial)
RELAY 1
(partial)
Fi er
+DC
—DC
RELAY 2
(partial)
RX
TX
RX
TX
SEL-2505 (partial)
IN
IN IN
Fi er-Optic
Mux
SEL-2505 2800
Relay
Fi er-Optic
Mux
SEL-2505 2800
Relay
Digital
Network
Interface
SEL-311C
Digital
Network
Interface
SEL-2505
2800 EM
Relay
Digital
Communications
Network
 Add communications-
assisted tripping to
existing relays.
 Add alternate commu-
nications channel to
pilot trip schemes.
 Isolated remote-
tripping via
fiber-optic links.
 Cross-trigger
event reports.
 Perform auxiliary
relay functions while
adding self-testing
capabilities.
 Create bus protection
using existing protec-
tion relays for simple
busses.
 Include an SEL-2100
for bus protection of
larger busses.
 Add direct transfer
triptoexisting
cogeneration
interconnections.
 Provide low-cost
teleprotection over
digital multiplexers.
 Provide a migration
path from
electromechanical
relays to MIRRORED
BITS relays.

4
SEL-2505 Remote I/O Module Date Code 20010214
Applications
f
Figure 5 educe Wiring From Control House to Outdoor Cabinets.
Exam le Distribution
Bus Protection:
Radial Feeders
Figure 6 shows an SEL-2505 application using existing distribution
relays and a SEL-2100 Protection Logic Processor to provide bus and
line protection for the radial system. When the overcurrent elements of
the transformer low-side relay pick-up and the overcurrent elements in
the feeder relays do not, the detected fault must be located on the bus.
Using relay overcurrent element status transmitted by the SEL-2505
devices, the SEL-2100 uses SELOGICâcontrol equations to issue a bus
trip via a MIRRORED BITS message to the protective relays through the
SEL-2505 modules. Unlike conventional schemes, there is no switch-
board wiring between relays. Eliminating this wiring reduces dc ground
exposure and replacing this wiring with SEL-2505s adds self-testing
and automatic communications path checking.
Figure 6 Distribution Bus Protection Application Example.
RELAY or
SEL-2100 (partial)
SEL Fi er-Optic
Transceiver
M
IRRORED B IT
Serial Port
+DC
SEL-2505 (partial)
RX TX
—DC
RX
TX
IN1
IN2 TC
52A
SEL-2800
SEL-2800
SEL-2800
SEL-2800
SEL-2800
Local User
Interface
5
4
SEL-2505
SEL-251
3
SEL-2505
SEL-251
2
SEL-2505
SEL-251
1
SEL-2505
SEL-251
SEL-2505
SEL-251C
2100
Protection
Logic
Processor
Transformer
HV LV
IRIG-B
Time
Receiver
SCADA
 Eliminate hard-
wiring from control
room to breaker or
motor-operated
disconnect switch.
 Reduce dc
ground exposure.
 Add trip/close path
continuity monitoring.
 Expand I/O capability
of relays with
MIRRORED BIT
communications
protocol.

5
Date Code 20010214 SEL-2505 Remote I/O Module
Functional Description
Functional Descri tion
MIRRORED BITS
Decoder/Encoder
and I/O Control
Figure 7 shows the functional block diagram of the SEL-2505. There is
aMIRRORED BIT decoder associated with the receive (RX) port and an
encoder for the transmit (TX) port. The decoder receives MIRRORED
BIT messages, checks that the receive address matches that set by
SW3 – 4, checks for data message errors, and then decodes each
message. If a Receive MIRRORED BIT (RMB) is a logical one for the
number of message frames set by SW5 – 8, the SEL-2505 asserts the
corresponding output contact.
If an RMB is a logical 0 for the number of message frames set by
SW5 – 8, the SEL-2505 deasserts the corresponding output contact. If
the communication channel is faulty or power is removed from the
device, the contact outputs are deasserted.
The decoder also monitors the received data and channel integrity.
Detected errors include: data errors, resynchronization, data over- and
under-run, parity, and framing errors. When it detects an error, the
SEL-2505 turns off the ROK LED and deenergizes the ALARM relay
(closing the alarm contact). If SEL-2505 detects two errors in a row, it
begins resynchronizing with the remote device. Once the remote device
receives this resynch message, it also deasserts its ROK message to
indicate a problem with the communications path.
The encoder converts the eight-contact inputs into the MIRRORED BIT
protocol and outputs this data to the transmit fiber port. This protocol is
designed to the security requirements outlined by IEC 834-1.
Figure 7 SEL-2505 Functional Block Diagram.
SEL-2505
Remote I/O Module
8 Contact
Outputs
Fi er-Optic Port
TMBn = Transmit M
IRRORED B IT n, RMBn = Receive M IRRORED B IT n
8 Contact
Inputs
Contact
Inputs
RMB1 = OUT1
•
•
•
RMB8 = OUT8
IN1 = TMB1
•
•
•
IN8 = TMB8
Contact
Outputs
TX
M
IRRORED
B
ITS
Encoder
RX
M
IRRORED
B
ITS
Decoder

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SEL-2505 Remote I/O Module Date Code 20010214
Configuring the SEL-25 5
Configuring the SEL-2505
The SEL-2505 uses a ten-position dip switch to set the TX and RX
addresses, to determine the number of received correct consecutive
messages for output contact control, and to program the baud rate of the
MIRRORED BITS communications (see Table 2 on page 7). The contact
consecutive messages feature is intended to increase the system
security for applications requiring higher security like direct transfer
tripping.
Figure 8 SEL-2505 Control Switch Position Identifications.
Setting the
Transmit and
Receive Addresses
You must set the TX address of each local SEL-2505 to match the
receive address of the remote device. Further, the TX and RX addresses
of each device should not be set to the same number. The SEL-2505
detects a loop-back condition when it receives its own transmit address
in the MIRRORED BIT message. When the SEL-2505 detects loop-back,
it illuminates the LOOP LED and extinguishes the ROK LED. The
SEL-2505 disables the contact outputs to prevent acting on its own
message during loop-back (i.e., output contacts go to their deenergized
state).
Table 1 Transm it and Receive Addr ess Setting s
Setting
Security Counts
for Received Data
Table 2 lists the data security count setting possibilities. When the data
security switch is set to “OFF,” the contact output follows its associated
RMB logical status. When the data security switch is set to “ON,” two
consecutive RMB messages of the same logical state are required to
assert/deassert the associated contact output. Note that each setting
switch controls an adjacent pair of contact outputs.
Switch No. Function
1,2 Transmit Address (TX)
3,4 Receive Address (RX)
5 OUT1,OUT2 Security Counts
6 OUT3,OUT4 " "
7 OUT5,OUT6 " "
8 OUT7,OUT8 " "
9,10 Baud Rate Setting
OFF
ON
10 9 8 6754321
Table 1 Transmit and eceive Address Settings
Switch 4 Switch 3 X Address Switch 2 Switch 1 TX Address
OFF OFF 1 OFF OFF 1
OFF ON 2 OFF ON 2
ON OFF 3 ON OFF 3
ON ON 4 ON ON 4

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Date Code 20010214 SEL-2505 Remote I/O Module
Configuring the SEL-25 5
Table 2 Data Sec urityepl Count Sett ings
For example, in Figure 8 on page 6, SW7 is set to “ON.” This requires
two consecutive messages to be confirmed before asserting/deasserting
OUT5 and OUT6, while all other outputs require only one message.
Setting
the Baud Rate
Table 3 lists the settings for the three baud rate options. For applications
using fiber connections between SEL devices, baud rate 38400 is
recommended. This recommendation is based on operating time. For
applications where a multiplexer or other communications device is
between the two MIRRORED BITS devices, baud rates 19200 or 9600 are
recommended. If the channel is operating intermittently, lowering the
baud rate will provide more stable performance in most cases.
Table 3 Prot ocol/Baud R ate Settings
Connecting
the SEL-2505 to
Other SEL Devices
The SEL-2505 uses the MB8 MIRRORED BITS protocol, transmits and
receives data at the baud rate set by switches 9 and 10, and is fiber
optic. When connecting the SEL-2505 to a MIRRORED BITS port of a
relay or the SEL-2100, the following are required:
1. An SEL-2800, SEL-2815, or SEL-2830 fiber modem.
2. The MIRRORED BITS protocol must be set to MB8; the MB
protocol is incompatible with the SEL-2505.
3. The SPEED setting must be set to match the setting of the
SEL-2505.
4. The transmit address of the local device must match the
receive address of the remote device.
If your relay does not have MB8 protocol, contact SEL for a firmware
upgrade.
The following examples show how to configure the SEL-351, SEL-321,
and the SEL-2100 to operate with the SEL-2505. Only the minimum
settings required to configure the communication interface between the
relays, SEL-2100, and SEL-2505 are shown. Consult the appropriate
instruction manual to ensure proper settings for your particular
MIRRORED BITS application.
Table 2 Data Security Count Settings
Switch Message 1 Message 2
Switch 5 (OUT1, OUT2) OFF ON
Switch 6 (OUT3, OUT4) OFF ON
Switch 7 (OUT5, OUT6) OFF ON
Switch 8 (OUT7, OUT8) OFF ON
Table 3 Protocol/Baud Rate Settings
Switch 10 Switch 9
OFF OFF MB8 Protocol @ 38400 Baud
OFF ON MB8 Protocol @ 19200 Baud
ON OFF MB8 Protocol @ 9600 Baud
ON ON Reserved

8
SEL-2505 Remote I/O Module Date Code 20010214
Testing the SEL-25 5
SEL-2505
TX_ADD=1(Switch1and2=OFF)
RX_ADD = 2 (Switch 3 = ON, Switch 4 = OFF)
PROTO/SPEED = 38400 (Switch 9 = OFF, Switch 10 = OFF)
SEL-351
PROTO = MB8A*
SPEED = 38400
RXID=1 TXID=2
* = MB8A or MB8B may be used
SEL-321
PROTO= MB8
SPEED = 38400
TX_ID = 2 RX_ID = 1
SEL-2100
PROTO = MB8
SPEED = 38400
TXID=1 RXID=2
Testing the SEL-2505
Testing an SEL-2505 requires another communicating device.
Examples include an SEL-2505, SEL-2100, or a relay with MIRRORED
BIT protocol and the appropriate fiber-optic transducer. The following
test procedure assumes you are using another SEL-2505 as the remote
communicating device. The test procedure for other communicating
devices is similar:
Step 1. Check the SEL-2505 dip-switch configuration settings.
Make certain the transmit address matches the receive
address of the remote device and that the baud rate is
identical.
Step 2. Connect the chassis ground terminal of the SEL-2505 to
ground (Terminal 1).
Step 3. Connect and apply rated voltage to the power supply
inputs of the SEL-2505 (positive to Terminal 4, negative to
Terminal 3). The ENABLE LED should illuminate. The
“b” form of the ALARM contact should remain closed and
the ALARM LED illuminates due to no communications.
Step 4. Press the LAMP TEST pushbutton. All LEDs should
illuminate. When you release the pushbutton, the LEDs
should extinguish.
Step 5. Connect the fiber-optic connections between the
SEL-2505s: transmit (TX) on one device to receive (RX)
on the other. The ROK, TX, and RX LEDs on both devices
should illuminate. In addition, the “b” contacts of the

9
Date Code 20010214 SEL-2505 Remote I/O Module
SEL-25 5 Operating Time Performance Diagram
ALARM contact should open and the ALARM LED
should extinguish.
Step 6. Apply rated voltage to IN1 on one device. The IN1 LED
should illuminate on this device. On the other SEL-2505,
the OUT1 contact should close and OUT1 LED should
illuminate.
Step 7. Repeat Step 6 for the remaining contacts.
Step 8. To test the loop-back feature, connect a single fiber
between the TX to RX on the same device. The LOOP
LED should illuminate and the ROK LED should
extinguish. Energize each input. No output contact should
assert.
SEL-2505 O erating Time Performance Diagram
Figure 9 shows the time to close an output contact of a remote
SEL-2505 given a contact closure on the local SEL-2505.
Figure 9 SEL-2505 to SEL-2505
End-to-End Operating Time Diagram.
Input
SEL-2505
Input
Contact
Power Fi er-Optic
Transmitter
0 ms Operate Window
Max. ms
SEL-2505
Output
Min. ms
Output
Fi er-Optic
Receiver
Baud Min. ms Max. ms
38400 5 10
19200 8 13
9600 14 19

10
SEL-2505 Remote I/O Module Date Code 20010214
Mechanical Diagram
Mechanical Diagram
Figure 10 SEL-2505 Dimensions and Drill Diagram.
6.50"
(165.1 mm)
12.50"
(317.5 mm)
2.50"
(63.5 mm)
11.20"
(284.5 mm)
13.33"
(338.6 mm)
2.175"
(55.25 mm)