ABB REL 356

ABB REL 356 Current Differential Protection
5-4
Testing
NOTE: For Medium and Long Reach Options (DCI assemblies G07 and G08) the Optical Power Attenuator must
be used to limit the Receiver Input Power to maximum of -11 dBm to prevent receiver saturation.
 Direct Digital Version (RS422/RS530)
Connect Pin 2 to Pin 3 (TXA to RXA)
Connect Pin 14 to Pin 16 (TXB to RXB)
Pin placement on DB-25 connector used is as follows:
STEP 1
Set: UNID = 0
KBPS = 64
XCLK = INT
LPBK = YES
Make sure that 52b contact input (TB-5 terminals 1-2) is de-energized.
Change the “OPBR” setting to “52B” to disable the open breaker code transmission. Change the “ALDT” setting to “NO”
since automatic delay time measurement is not possible with communication channel in a “Loopback” configuration.
Turn the dc supply connected to the REL 350’s dc (Battery) inputs “off” for 1 second & then back “on” again to re-initialize
the modem’s “ALDT” setting on power-up sequence.
The Monitoring Function CHRX (Received Line Status) should read NORM.
STEP 2
Disconnect above described Loopback Connections. The display CHRX should read CHTB (Channel Trouble).
STEP 3
Reconnect the Loopback Connection. The display CHRX should return to NORM after a short time delay.
1
2
3
4
13
14
15
16
25