Harris Corporation RF Communications Division XG-100LPA Manuale Utente
14221-1200-4010, Rev. B
50
9. DC POWER INSTALLATION
Refer to the wiring diagram at the end of this manual as necessary when performing the
wiring procedures presented in this section.
9.1 OVERVIEW OF ON/OFF POWER WIRING CONFIGURATIONS
Radio on/off power control is accomplished by the control head. When the control head is turned on, it
“wakes-up” the MRU via data activity on the CAN link. The MRU automatically powers-up the LBPA
when the MRU is powered on. The following power wiring configurations are supported:
Any DC input power provided to the radio shall be no higher or lower than
13.6 volts DC
10%. The DC input power should be free and clear of any AC noise or DC
spikes above 18 volts. If the vehicle cannot meet these requirements, then DC conditioning
will be required before any DC power is connected to the radio. This includes conditioning
for both the radio’s main DC power input lead and for its switched ignition sense power
input. DC conditioning can be accomplished by a noise filter or DC isolation equipment
such as Harris part number FL-018314-001 or FL-018314-002, or similar units with equal
specifications. The fuse must be placed in-line before any noise filter. Contact TAC for
additional information.
Radio turns on and off automatically with vehicle’s ignition switch/key — This configuration
allows the on/off state of the vehicle’s ignition switch/key to control the on/off power state of the
radio. The white wire of the control head’s DC Power Cable is connected to a fused switched power
source, typically identified as vehicle “Accessory” power. This source must switch on (up to positive
(+) battery voltage potential) when the vehicle’s ignition switch/key turns on, and it must switch off
(to near zero volts) when the ignition switch/key turns off. The required fuse rating is 3 amperes.
When using this configuration, the control head’s on/off/volume control must be left in the on
position for automatic power-up/down to function properly.
Radio turns on and off with a manual switch — This configuration is used when, for example, the
radio must remain on even when the ignition key must be removed from the vehicle and a separate
on/off switch is acceptable. The white wire of the control head’s DC Power Cable is connected to one
side of a manually-controlled switch, and the other side of this switch is connected to unswitched and
fused vehicle power. The required fuse rating is 3 amperes. When using this configuration, the control
head’s on/off/volume control must be left in the on position for automatic power-up/down to function
properly.
Radio turns on with control head’s on/off/volume control (“hot wired”) — This configuration
allows radio on/off power control only via the control head’s on/off/volume control. It may be desired
if, for example, the radio must remain on even when the ignition key must be removed from the
vehicle and a separate on/off switch is not desired and/or not acceptable. The white wire of the
control head’s DC Power Cable must be connected to unswitched and fused vehicle power. The
required fuse rating is 3 amperes.
NOTE