Startco FPU-16 - Ict-2 Connections; Operation Count Input; Program-Change Lockout; Analog Output

Startco Engineering Ltd. Page 29
FPU-16 Feeder Protection Unit Rev. 1
Pub. FPU-16-M, November, 1997 Downloaded from the Internet, see Disclaimer.
4.4.5 OPERATION COUNT INPUT
Contact closures can be counted by connecting the contact between terminals
17 and 19. Shielded cable is recommended for cable lengths greater than 1 m
(3 ft). If shielded cable is used, ground the shield at the FPU-16 only.
4.4.6 PROGRAM-CHANGE LOCKOUT
As explained in Sections 2.3 and 2.5, program-change lockout prevents
unauthorized or unintentional changes. It is recommended that a keylock switch
be connected to FPU-16 terminals 20 and 21 to allow programming. If the
switch is mounted more than 1 m (3 ft) from the FPU-16, use shielded cable and
ground the shield at the FPU-16 end only.
4.4.7 ANALOG OUTPUT
An isolated analog output is available at terminals 23 and 24. Terminal 23 is
negative. Use shielded cable and ground the cable shield at the receiver.
4.4.8 COMMUNICATIONS INTERFACE
The optional RS-485 communications interface replaces the analog output at
terminals 23 and 24. See communications interface manuals.
4.5 ICT-2 CONNECTIONS
The FPU-16 uses an ICT-2 interface CT to simplify wiring and to minimize CT
burden. The ICT-2 contains four signal-conditioning interface transformers
which are interconnected as shown in Figure 10. These transformers isolate the
FPU-16 from the phase and earth-fault CT's. Also, they eliminate the need for
CT shorting contacts when the FPU-16 is disconnected. Phase-CT and earth-
fault-CT secondaries can be simultaneously grounded through terminal 22 and
a jumper to terminal 20. For in-line applications, the CT secondaries can be
isolated by removing shorting screws A, B, and C through holes in the bottom of
the ICT-2. See Figure 5.
4.5.1 STANDARD CONNECTION
Standard connections with three, phase CT's and an earth-fault CT are shown in
Figure 11. Dotted lines indicate 1-A-CT connections. Use shielded cable for
EFCT-1 or EFCT-2 connections. Ensure that only current-carrying phase
conductors pass through the earth-fault CT window and that ground conductors
do not. For applications where the CT secondaries must be grounded at
another location, remove shorting screws A, B, and C.