User's Manual

19
Date Code 20170317 Instruction Manual SEL-FT50/SEL-FR12 Fault Transmitter and Receiver System
System Installation
Figure 15 Switch Selections Labels
Setting the Unit ID
The SEL-FR12 Fault Receiver receives wireless signals from as many as 12
SEL-FT50 Fault Transmitters on the same network, defined by the
Network ID selection in the SEL-FT50/SEL-FR12 system.
To allow the SEL-FR12 to distinguish which fault transmitter has sent a
message, each SEL-FT50 transmits a Unit ID field as part of the message (the
Unit ID is a number from 1 to 12).
The following lists the requirements when planning the Unit IDs to use in a
system:
➤ Unit IDs cannot be duplicated on the network.
➤ Not all Unit IDs need to be present.
➤ Unit IDs should be grouped in three-phase locations as trios
(see Table 3).
➤ Single-phase and two-phase applications are possible in
specific situations.
➤ Unit IDs should be marked on the system record for later
installation and commissioning work.
➤ Each SEL-FT50 Unit ID is configurable and is selected by the
Unit ID control switches inside the housing.
Setting the Network ID
Configure your SEL-FT50 Fault Transmitters to communicate on the same
network as your SEL-FR12 by giving both devices the same Network ID.
Devices with different Network IDs cannot communicate.
Setting Fault Pickup
The topic of power system coordination is outside the scope of this guide. An
overcurrent element must supervise SEL-FT50 data when used in trip
decisions or other operations affecting protection. Choose an SEL-FT50 Fault
Pickup to be at or below the upstream protective device (e.g., recloser control)
supervising the overcurrent pickup setting (expressed in primary amperes).
Because the SEL-FT50 measurement accuracy is not as accurate as a relay,
take care when choosing your fault pickup settings. The measurement
accuracy for each trip threshold is spelled out in the specifications section.