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Model BD306 Dual-Input Pump Controller Instruction Manual
7.10.3. Fail-Safe Operation
The following table indicates how the relays behave based on the fail-safe selection for each
relay:
Fail-Safe
Selection
Non-Alarm State
Alarm State
Power Failure
NO
NC
NO
NC
Off
Open
Closed
Closed
Open
Relays go to
non-alarm state
On
Closed
Open
Open
Closed
Relays go to
alarm state
7.10.4. Front Panel LEDs
The LEDs on the front panel provide status indication for the following:
Note: NO = Normally Open, NC = Normally Closed. This refers to the condition
of the relay contacts when the power to the meter is off.
LED
STATUS
1
Alarm 1
2
Alarm 2
3
Alarm 3
4
Alarm 4
LED
STATUS
5
Alarm 5
6
Alarm 6
7
Alarm 7
8
Alarm 8
The meter is supplied with four alarm points that include front panel LEDs to indicate alarm
conditions. This standard feature is particularly useful for alarm applications that require
visual-only indication. The LEDs are controlled by the set and reset points programmed by
the user. When the display reaches a set point for a high or low alarm, the corresponding
alarm LED will turn on. When the display returns to the reset point, the LED will go off. The
front panel LEDs respond differently for latching and non-latching relays.
For non-latching relays, the LED is always off during normal condition and always on
during alarm condition, regardless of the state of the relay (e.g. Relay acknowledged after
alarm condition).
For latching relays, the alarm LEDs reflect the status of the relays, regardless of the alarm
condition. The following tables illustrate how the alarm LEDs function in relation to the re-
lays and the acknowledge button (Default: F3 key assigned to ACK):
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