Sel 411L - Figure 3.184 C37.94 Back-To-Back Connection

P.3.269
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
87L Communication and Timing
Figure 3.184 C37.94 Back-to-Back Connection
Direct Fiber-Optic
Interfaces
The fiber-optic interfaces on the relay use eye-safe lasers and sensitive
detectors to achieve 40 dB of system gain. This yields up to a 80 km link on a
pair of 9 micron single-mode fibers at 1300 nm, 30 km on 62.5 micron
multimode fibers at 1300 nm, and 120 km link on a pair of 9 micron single-
mode fibers at 1550 nm. Even though the 1550 nm direct-fiber interface
provided on the relay is eye safe, you should never look into a fiber transmitter
or into a fiber conductor. Connect the relays as shown in Figure 3.184.
Power Budget Example (1300 nm, 9 Micron Fiber)
TX
Relay (1) Relay (2)
RX
TX
RX
NOTE: All fiber-optic interfaces on
the relay use eye-safe lasers except
for the 1300 nm C37.94 card which
uses an LED.
CAUTION
Use of controls or adjustments, or
performance of procedures other than
those specified herein, may result in
hazardous radiation exposure.
WARNING
Do not look into the fiber (laser)
ports/connectors.
WARNING
Do not look into the end of an optical
cable connected to an optical output.
WARNING
Do not perform any procedures or
adjustments that this instruction
manual does not describe.
WARNING
During installation, maintenance, or
testing of the optical ports, use only
test equipment qualified for Class 1
laser products.
WARNING
Incorporated components, such as
LEDs, transceivers, and laser emitters,
are not user serviceable. Return units
to SEL for repair or replacement.
Loss Data
Connector loss: 0.75 dB per connector
Splice loss (fusion): 0.3 dB per splice
Distance between splices: 3 km
Fiber loss @ 1300 nm: 0.4 dB per km
Losses (66 km line)
Connector loss (4 connectors): 3.0 dB
Splice loss (23 splices): 6.9 dB
Fiber loss (66 km): 26.4 dB
Total losses: 36.3 dB
Budget
Relay 1300 nm fiber interface system gain: 40.0 dB
Minus total losses: –36.3 dB
Margin: 3.7 dB