ABB REL 301, Instruction Manual

Page: 93 / 132

I.L. 40-386.3
4-10 (10/94)
near the top. (On the top of the front panel and on the left for horizontally mounted
relays.) Only the first three poles, #1, #2 and #3, of the switch, are used to set the com-
munications bit rate. Refer to
Table 4-6 for the correct position of the switch poles.
Note that settings 110 and 111 result in the default bit rate of 1200 bps.
4.7.2 OPERATIONS
When the communication hardware is in place, communicating with the front requires
pressing the push-button beside the connector in order to switch from the rear to
front. Thereafter, the communication will remain with the front until no data transfer
has taken place for two minutes.
RCP operations are identical for front and rear communication (RS-232C or INCOM).
It is possible that the communication is unsuccessful the first time after a relay power-
up or switching between protection and recloser. In this case, a second attempt proves
to be successful.
4.7.3 Troubleshooting
In the event the communication remains unsuccessful, first make sure that the front
communication push-button has been depressed, the relay is powered and the con-
nection is good.
For further testing, remove the front cover and check that the bit rate (baud) on the
communication board (dip switches: refer to
Dip Switch Setting Chart above ) is set
to correspond to the one displayed at the bottom right of the RCP display.
If after these verifications the problem remains, try to remove the power from the relay
and apply it again. If the communication still fails (several attempts), the communica-
tion board needs to be serviced.
4. 8. SIXTEEN FAULT TARGET DATA
The REL 301/302 saves the latest 16 fault records, but only the latest two fault
records can be accessed from the front panel. For complete 16 fault data, one of the
communication interface devices are necessary. The activation of fault data storage is
controlled by setting FDAT. (Refer to Section 3.4.16 for detailed information.) The 16
intermediate fault targets are a standard feature. The activation of data storage is
based on the OSC Data (
OSC ) setting (see next section).
4. 9. OSCILLOGRAPHIC DATA
Sixteen sets of oscillographic data are stored in REL 301/302. Each set includes seven
analog traces (Va, V
b
, V
c
, I
a
, I
b
, I
c
and I
p
), with one cycle pre-fault and 7-cycle fault
information, and 20 sets of digital data based on 8 samples per cycle.
The oscillographic data OSC Data ( OSC ) collection can be set for Trip ( TRIP ), Zone2
( Z2TR ), Zone 2, Zone3 ( Z2Z3 ), and
∆
v or
∆
I (
∆
V
∆
I). For setting of OSC = TRIP, data
are collected for the trip events. The data collection is started from dVdI if the trip oc-
curs within 7 cycles. For OSC = Z2TR, the data collection is triggered by Zone2 pickup
or any type of trip. For OSC = Z2Z3, the collection is triggered by either Zone2 or Zone3
pickup (including the Zone3 reverse setting) or trip. For OSC =
∆
V
∆
I, the data collec-
tion is caused by any line disturbance, e.g., a sudden phase current change (by 1 amp)
or a ground current change (by 0.5 Amp), or a voltage change (DV) greater than 7Vdc.