Fusing; Power Supply Conditioning; Power Connector On The Gx450 Gateway - Sierra Wireless AirLink GX450 Hardware User's Manual

Fusing

For DC installations, Sierra Wireless recommends fusing the power input using a 2.0 A
fast-acting fuse. Install the fuse on the positive line, as shown in
For vehicle installations, use an automotive fuse.

Power Supply Conditioning

For automotive applications, the supply voltage may momentarily drop below 9.0 V during
engine cranking, causing the GX450 gateway to reboot. If this happens, the gateway
restarts automatically and is ready for use once the reboot is complete. If your application
requires the gateway to continue operating during engine cranking, add external power
conditioning circuits to ensure the supply voltage does not drop below the rated value (9.0
V).

Power Connector on the GX450 Gateway

If you are using the DC power cable to connect the gateway to a power source:
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See
Rev. 11 July 2019
Pin 1—Use the red wire in the DC cable to connect Pin 1 to the power source.
Include a 2.0 A fast-acting fuse in the input power line. Sierra Wireless recommends
using a continuous (unswitched) DC power source. For installations that require the
device to be turned on/off, Sierra Wireless recommends using the Ignition Sense (Pin
3) input for this purpose.
Note: When the gateway switches to Low Power mode based on a Low Voltage trigger, the
voltage is monitored on the Red, Power wire.
Pin 2—Use the black wire in the DC cable to connect Pin 2 to ground. See also
Grounding the GX450 Gateway Chassis
Pin 3 (Ignition Sense)—Sierra Wireless recommends always using the Ignition Sense
wire to turn the gateway off. It should not be turned off by disconnecting the power.
For installations where the GX450 gateway is turned on/off, use the white wire in the
DC cable connected to Pin 3 to:
· Turn the gateway on/off with the vehicle ignition
Note: To turn the gateway on/off with the vehicle ignition, Sierra Wireless strongly recommends
using an unswitched VCC on Pin 1 (Red, Power wire on DC cable) with Pin 3 (White, Ignition
sense wire on DC cable) connected to the ignition.
· Turn the gateway on/off with a low voltage disconnect device
Note: To turn the gateway off when the voltage drops below a defined level, connect Pin 3 to
an external low voltage disconnect. See
Pin 4 (General Purpose I/O)
connect Pin 4 to a switch or relay on an external device you want to monitor. For
more details, see page
Figure 2-20 and Table
on page 26.
Figure 2-20
(Optional)—Use the green wire in the DC cable to
35.
2-4.
33
Installation and Startup
Figure 2-20
on page 34.
on page 34.
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