ACR&Artex 2-Wire ELT__RSWT Interface - Manual (Page 10)

ACR Electronics, Inc. 570-0049 Revision B
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Page 10 of 30
3.2 WIRING OVERVIEW
Due to the range of ELT installation available, this manual does not illustrate each single wiring
diagram pertaining to a specific ELT because the wiring is in fact very generic to all Artex
beacons. All Artex ELTs follow the same wiring criteria, and have 5 basic electrical lines
connecting the toggle switch to the beacon:
1. Light: This pin turns ON the toggle switch LED. The ELT output is a square wave
pulse with 280 millisecond period. The ON period of the pulse is 140 milliseconds
and the OFF period is 140 milliseconds.
2. Reset 1: This pin enables the ELT to determine the ON or ARM position of the toggle
switch.
3. Reset 2: This pin enables the ELT to determine the ON or ARM position of the toggle
switch.
4. External ON: This pin turns ON the ELT when it is grounded.
5. Ground: This pin is tied to Aircraft DC ground and references all control input and
output signals.
The interface system alleviates the need to install the 5 electrical wires across the aircraft when
the ELT and the toggle switch are installed apart. As such, the system uses 2 interfaces to
convert the typical 5-wire communication line down to 2 wires.
The ELT interface 453-0041 has a built-in horn that is powered by the ELT.
Upon initialization of either the ELT or the toggle switch 140-3349, the event communication
latency between these two products is less than 2 seconds. As such, a change in the lamp state
(LED) also takes place within 2 seconds.
Once the system is operational, the standard LED flash rate is ~140 msec.
The quiescent state power consumption (with the toggle switch in the “ARM” position) of the
interfaces is less than 100 μA.
The color of the two communication wires between the interfaces is inconsequential, but each
wire must:
1. Have the proper gauge (22-26).
2. Be properly connected to the appropriate contact on the D-sub mating connector of
each interface as shown in the appropriate wiring diagram.
The voltage range of the 453-0032 interface is 6.5 to 30 VDC, but aircraft power is typically 14
and 28 VDC.
The interface 453-0041 contains a latching relay so a slight clinking noise should be expected
during operation.
INSTALLATION SEQUENCE:
1. Install the switch (140-3349)
2. Install the front module (453-0032)
3. Install the rear module (453-0041)
4. Apply power source to modules
5. Connect ELT
NOTE: If this sequence is not followed during installation it is possible for the latching
relay to be latched “ON” with the power off, causing the ELT to turn on when connected.
Reset this condition by connecting power and toggling the switch from ARM to ON and
back to ARM.