User's Manual

10
SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System Instruction Manual Date Code 20170317
Safety Information
Tripping the Right
Recloser Faster
You can protect a distribution feeder with multiple reclosers. In a radial
system, to optimize selectivity, users want the recloser closest to the fault to
operate for that fault. For this reason, reclosers at the end of the distribution
line are set to trip first and the close-in reclosers are set to delay their tripping.
Figure 10 shows a fault in Zone R1. In a conventional protection design,
assuming the reclosers use a fuse-blowing scheme, R1 clears this fault, but
only after it gives Zones R2, R3, and R4 a chance to operate. This situation
results in a long fault duration that stresses the system and impacts the power
quality on other substation loads.
Figure 10 Radial Distribution Line With Multiple Reclosers
Fix this problem by using an SEL-FT50/SEL-FR12 system. In Figure 10, the
SEL-FT50 detects the fault and immediately transmits the information to the
SEL-FR12, which then sends this information to the recloser control at R1.
Because R1 knows that the fault is in its zone, it trips without waiting for the
downstream reclosers, avoiding the unnecessary coordination delay.
Safety Information
Regulatory
Information
The SEL-FT50 is approved for use only with specific output power
configurations that have been tested and approved. Modifications to the
SEL-FT50, the SEL-FR12, the antenna system, and the power output that
have not been explicitly specified by the manufacturer are not permitted and
may render the radio noncompliant with applicable regulatory authorities. The
radio equipment described in this manual emits radio frequency energy.
Professional installation is required.
This equipment has been tested and found to comply with the limits for
Class A digital devices, pursuant to FCC Part 15 Rules. These limits are
designed to provide reasonable protection against harmful interference when
the equipment is operated in a commercial environment. This equipment
generates, uses, and radiates radio frequency energy, and if not installed and
used in accordance with the instruction manual, may cause harmful
interference to radio communication. Operation of this equipment in a
residential environment is likely to cause harmful interference, in which case
the user will be required to correct the interference at his/her own expense.
R1
SEL-FR12
SEL-651R-2
R2
R3 R4
SEL-FT50
CAUTION
Although the power level is low,
concentrated energy from a
directional antenna may pose a
health hazard. Do not allow users to
come closer than 23 cm (9 in) to the
transmitter when it is operating.
DANGER
Install fault transmitters and sensors
in accordance with normal safe
operating procedures. These
instructions are not intended to
replace or supersede existing safety
or operating requirements. Only
trained qualified personnel with
knowledge of high voltage safety
should install or operate fault
transmitters.