Trip Blocking; Supervision Items And Alarms - Toshiba GRE110 Instruction Manual

The LCD messages are shown on the "Auto-supervision" screen, which is displayed automatically
when a failure is detected or displayed by pressing ▼ key. The event record messages are shown
on the "Event record" screen by opening the "Record" sub-menu.
The alarms are retained until the failure is recovered.
The alarms can be disabled collectively by setting the scheme switch [A.M.F.] to "OFF". The
setting is used to block unnecessary alarms during commissioning, test or maintenance.
When the Watchdog Timer detects that the software is not running normally, LCD display and
event recording of the failure may not function normally.
Supervision Item
AC input imbalance
monitoring
A/D accuracy check
Memory monitoring
Watchdog Timer
Power supply monitoring
Trip circuit supervision
CB state monitoring
CB condition monitoring
Trip count alarm
Operating time alarm
count alarm
∑I
y
(1): Diverse messages are provided as expressed with " Err:---" in the table in Section 6.7.2.
(2): The LED is on when the scheme switch [SVCNT] is set to "ALM" and off when set to "ALM &
BLK" (refer to Section 3.3.6). The message "Relay fail-A" is recorded when the scheme switch
[SVCNT] is set to "ALM". This monitoring is NOT for models 820 and 821.
(3): Whether the LED is lit or not depends on the degree of the voltage drop.
(4): The binary output relay "FAIL" operates except for DC supply fail condition.

3.3.6 Trip Blocking

When a failure is detected by the following supervision items, the trip function is blocked as long as
the failure exists, and is restored when the failure is removed.
• A/D accuracy check
• Memory monitoring
• Watchdog Timer
When a fault is detected by the AC input imbalance monitoring, the scheme switch [SVCNT]
setting can be used to determine if both tripping is blocked and an alarm is output (ALM&BLK), or
if only an alarm is output (ALM).
Table 3.3.1 Supervision Items and Alarms
LCD LED
Message "IN SERVICE"
Err: CT On/Off (2)
(1) Off
---- Off
Err: DC Off
Err:TC On
Err:CB On
ALM:TP
On
COUNT
ALM: OP On
time
On
ALM:∑IY
 74 
LED LED
"ALARM" "Relay fail"
On (4)
On (4)
On (4)
(3) Off
On Off
On Off
On Off
On Off
On Off
6 F 2 T 0 1 7 2
Event record Message
CT err (2)
Relay fail or Relay fail-A
Relay fail
----
Relay fail-A
TC err, Relay fail-A
CB err, Relay fail-A
TP COUNT ALM,
Relay fail-A
OP time ALM, Relay fail-A
∑IY-A ALM, ∑IY-B ALM or
∑IY-C ALM, Relay fail-A