Assembly Instructions

Chapter 3
Universal Relay Controller Installation
The Universal Relay Controller (URC) is an extension of an orderable accessory for O7 or O9 control
head.
URC is used to control high power switching peripherals, for example, lightbar. URC works on all
power application controlled lightbars. URC is connected to the transceiver GCAI port. The URC
design consists of a microcontroller and uses ten relays to control the switching device. A separate
ground for isolation exists between the relay and MCU sections, which is provided by the use of
iCoupler from Analog Devices. Each relay is connected to an output with 15 A fuse. The maximum load
allowed on each output is 12 A. Two cables, each with the maximum of 60 A, can be used to connect
to the input connector at the bus bar. Each cable is connected with a 60 A circuit breaker. One-wire
EEPROM is employed to enable GCAI to recognize the URC accessory ID. CPS can be used to
program the relay patterns.
When installing URC, make sure to plan the installation carefully and leave more room in the front and
rear of the box for cabling and accessory connections; and also to the sides of the radio so that you
may access and install the trunnion screws.
The recommended mounting location for URC is in the car trunk, either next to the transceiver or within
the area not further than 4.5 m away from the transceiver. Ensure that sufficient cooling is provided. Do
not cover URC with baggage, blankets, and so on.
CAUTION: Do not backfeed power into URC.
3.1
Universal Relay Controller Mounting
The mounting location must be accessible and visible. Select a location that permits routing the cable
as directly as possible.
Prerequisites:
NOTICE: For optimum URC performance, orient the mounting trunnion as shown in the
following figure.
Figure 80: Universal Relay Controller Orientation
An adjustable trunnion, which allows several mounting positions, is supplied for mounting the URC.
The installation must not interfere with the operation of the vehicle or its accessories.
MN005720A01-AB
Chapter 3: Universal Relay Controller Installation
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