Hitachi CONVENTION 14 Instruction Manual page 194

The alarm relay output can be configured in two main ways:
Trip/Power Loss Alarm – The alarm relay is configured as normally closed
(C036=1) by default, shown below (left). An external alarm circuit that detects
broken wiring also as an alarm connects to [AL0] and [AL1]. After powerup and
short delay (< 2 seconds), the relay energizes and the alarm circuit is OFF. Then,
either an inverter trip event or an inverter power loss will de-energize the relay
and open the alarm circuit
Trip Alarm – Alternatively, you can configure the relay as normally open (C036=0),
shown below (right). An external alarm circuit that detects broken wiring also as
an alarm connects to [AL0] and [AL2]. After powerup, the relay energizes only
when an inverter trip event occurs, opening the alarm circuit. However, in this
configuration, an inverter power loss does not open the alarm circuit.
Be sure to use the relay configuration that is appropriate for your system design. Note
that the external circuits shown assume that a closed circuit = no alarm condition (so
that a broken wire also causes an alarm). However, some systems may require a closed
circuit = alarm condition. In that case, then use the opposite terminal [AL1] or [AL2]
from the ones shown.
N.C. contacts (C036=01)
During normal operation When an alarm occurs or
AL0 AL1 AL2
Power
Load
supply
Power Run Mode
ON Normal
ON Trip
OFF –
when power is OFF
AL0 AL1 AL2
Power
Load
supply
AL0-AL1 AL0-AL2
Closed Open
Open Closed
Open Closed
N.O. contacts (C036=00)
During normal operation
or when power is OFF
AL0 AL1 AL2
Power
Load
supply
Power Run Mode
ON Normal
ON Trip
OFF –
4 − 45
4 45
When an alarm occurs
AL0 AL1 AL2
Power
Load
supply
AL0-AL1 AL0-AL2
Open Closed
Closed Open
Open Closed