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L200 Inverter
Operations
and Monitoring
4–35
Internal Relay Output
The inverter has an internal relay output with
normally open and normally closed contacts (Type
1 form C). The output signal that controls the relay
is configurable; the Alarm Signal is the default
setting. Thus, the terminals are labeled [AL0],
[AL1], [AL2], as shown to the right. However, you
can assign any one of the nine intelligent outputs to
the relay. For wiring purposes, the general terminal
function are:
• [AL0] – Common contact
• [AL1] – Normally open contact
• [AL2] – Normally closed contact
The relay itself can be configured as “normally open or closed.” Parameter C036, Alarm
Relay Active State, is the setting. This setting determines whether or not the relay coil is
energized when its output signal is OFF:
• C036=00 – “Normally open” (relay coil is de-energized when output signal is OFF)
• C036=01 – “Normally closed” (relay coil is energized when the output signal is OFF)
Since the relay already has normally open [AL1]
and normally closed [AL2] contacts, the purpose of
the ability to invert the relay coil’s active state may
not be obvious. It allows you to determine whether
or not an inverter power loss causes the relay to
change state. The default relay configuration is the
Alarm Signal (C026=05), as shown to the right.
And, C036=01 sets the relay to “normally closed”
(relay coil normally energized). The reason for this
is that a typical system design will require an
inverter power loss to assert an alarm signal to
external devices.
The relay can be used for other intelligent output
signals, such as the Run Signal (set C026=00). For
these remaining output signal types, the relay coil
typically must NOT change state upon inverter
power loss (set C036=00). The figure to the right
shows the relay settings for the Run Signal output.
If you assign the relay an output signal other than
the Alarm Signal, the inverter can still have an
Alarm Signal output. In this case, you can assign it
to either terminal [11] or [12], providing an open
collector output.
AL0
AL2AL1
Inverter logic
circuit board
AL0
AL2AL1
Inverter logic
circuit board
AL
C026=05
C036=01
Relay shown with inverter
power ON, Alarm Signal OFF
AL0
AL2AL1
Inverter logic
circuit board
RUN
C026=00
C036=00
Relay shown with inverter
power ON, Run Signal OFF