Airfield Lighting
Safegate Group
Manual
Date: October 2016
Ref: SL-RE-E_SL-RT-E_SL-RN-E_SL-RTN-E_SL-SB-E
Version: 1.4
Page 33 of 42
3.3
CONNECTING THE LIGHT FIXTURES IN A SERIES CIRCUIT
3.3.1
Operational Characteristics
The extent of use of all SafeLED
IQ functionality is determined by
the application. All functionality
described in this document is not
necessarily used at a specific
installation. This section is a
summary of common functionality
available in SafeLED IQ.
3.3.2
Power On or Default State
IQ is configured to set the lamp to
a predefined state when the series
circuit is energized. This feature is
called
default state
and the options
are LAMP ON, LAMP OFF or
LAMP FLASHING. The option to
select depends on the light function
for a SafeLED IQ light fixture and
the operative requirements.
3.3.3
Safe State
If communication between the SafeLED IQ and the SCM is interrupted or lost, IQ
functionality (after a programmable timeout) sets the lamp to a predefined state known
as
safe state
. Safe state can be set to
LAMP ON
,
LAMP OFF
,
LAMP FLASHING
or
no change
.
3.3.4
Command Memory
When current in the series circuit is lost, for example if a CCR is turned off or for any
other reason, SafeLED IQ remembers the current lamp status for a limited amount of
time. The IQ can be configured, once current is restored in the circuit, to set the lamp
to the previous state, typically the last commanded state before a power loss. This
feature, when enabled, overrides the default state.
It is possible to apply a condition based on the amount of time current was lost. The
SafeLED IQ sets the lamp to the default state if current was restored beyond this time
limit. The time limit is programmable from 1 to 20 seconds approximately.
3.3.5
SoftON/SoftOFF
The SafeLED IQ can be programmed to delay the physical turning on or off of the
lamp upon reception of a command from the SCM. The purpose of
SoftON/SoftOFF
is to mitigate the sudden load change to which the CCR is subjected when a large
portion of the load is commanded on or off with a single command. The command
acknowledge from the SafeLED IQ is unaffected, and thereby neither is the response
time. Without this feature it may not be possible to turn on/ off all or most of the light
fixture on a circuit with a single command, without the CCR tripping because of over-
or under-current.
The physical delay is programmable on an individual level in 10ms increments. There
is no response time impact when
SoftON/SoftOFF
is enabled.
FIGURE 47
– SERIES CIRCUIT CONNECTION
