Hitachi Relion 670 Series Applications Manual page 309

1MRK511407-UUS Rev. N
An optical budget calculation should be made for the actual case. For medium range LDCM and long
range LDCM the recommendation is to use the LowPower setting to minimize the power consumption
and keep the heat dissipation at minimum.
The HighPower setting adds 3 dBm extra optical power and can be used to increase the margin at
distances close to maximum.
Table 37:
Type of LDCM
Type of fibre
Modem type
Contact type
Maximum output
1)
power
Minimum receiver
sensitivity
Optical link budget
1) Maximum output power is measured with 1 m of the selected fiber and the high power mode.
2) Applicable for revision r11 and later.
3) The optical budget includes a satisfactory margin for aging in transmitter and receiver during 20–30 years.
Table 38:
Type of LDCM
Type of fibre
Modem type
Typical attenuation in
fibre-optic cables
Attenuation/Contact
Factory splice
attenuation
Repair splices
Fiber margin for aging
Table 39:
Type of LDCM
Type of fibre
Modem type
Maximum distance
Attenuation in fibre-
optic cables
Table continues on next page
Phasor measurement unit RES670
Application manual
Optical budgets with C37.94 protocol
Short range (SR)
Multi-mode fiber glass
50/125 μm
1MRK0002122-AB
ST
–18.2 dBm
–30 dBm
3) 9 dB
Example of input data for calculating the optical budget (maximum distance)
Short range (SR)
Multi-mode fiber glass
50/125 μm
1MRK0002122-AB
3 dB/km
1.5 dB/ST
0.5 dB/splice
0.3 splices/km
0.25 dB/splice
0.1 splices/km
0.1 dB/km
Example of calculating the optical budget (maximum distance)
Short range (SR)
Multi-mode fiber glass
50/125 μm
1MRK0002122-AB
2 km
6 dB
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Short range (SR) Medium range (MR)
Multi-mode fiber glass Single-mode fiber
62.5/125 μm glass 9/125 μm
1MRK0002122-AB 1MRK002311-AA
ST FC/PC
–13.7 dBm –3.2 dBm
- 1.2 dBm
–32.5 dBm –32 dBm
18.8 dB 28.8 dB
30.8 dB
Short range (SR) Medium range (MR)
Multi-mode fiber glass Single-mode fiber
62.5/125 μm glass 9/125 μm
1MRK0002122-AB 1MRK002311-AA
3 dB/km 0.32 dB/km
1.5 dB/ST 0.3 dB/FC/PC
0.5 dB/splice 0.08 dB/splice
0.1 splices/km 0.1 splices/km
0.25 dB/splice 0.1 dB/splice
0.1 splices/km 0.05 splices/km
0.1 dB/km 0.01 dB/km
Short range (SR) Medium range (MR)
Multi-mode fiber glass Single-mode fiber
62.5/125 μm glass 9/125 μm
1MRK0002122-AB 1MRK002311-AA
3 km 80 km
9 dB 25.6 dB
Remote communication
Long range (LR)
Single-mode fiber
glass 9/125 μm
1MRK002311-BA
FC/PC
–1.3 dBm
2)
–32 dBm
30.7 dB
2)
Long range (LR)
Single-mode fiber
glass 9/125 μm
1MRK002311-BA
0.21 dB/km
0.3 dB/FC/PC
0.08 dB/splice
0.1 splices/km
0.1 dB/splice
0.05 splices/km
0.01 dB/km
Long range (LR)
Single-mode fiber
glass 9/125 μm
1MRK002311-BA
120 km
25.2 dB
Section 20
303