User's Manual

INSTALLATION
FIXED STATIONS
372 ENVOY™ TRANSCEIVER REFERENCE MANUAL
Power supply factors
Voltage drop
The most common causes of voltage drop along a cable are:
• the diameter of the wire is too thin
• the length of the cable is too long
The average current consumption of a transceiver is low except during transmission
of voice and data peaks, where high current is needed for short intervals. The power
supply cable needs to be sufficiently heavy to supply these current peaks without
excessive voltage drop.
Incorrect wiring techniques, including poor choice of connection points and incorrect
use of terminal lugs, can also cause a voltage drop.
Related links:
Power and control cabling on page 357
Fuse protection
An external fuse must be fitted in the active wire as close as possible to the battery to
ensure there is no risk of fire if the cable is damaged. The fuse must be of a type that
has a low voltage drop at peak currents.
NOTE: A 32 A cartridge fuse (Codan part number 15-00711) is recommended.
Related links:
Protecting the cables on page 358
Noise interference
The transceiver has noise-rejection circuitry and, provided correct connection and
routing of the power cable are established, noise interference via the power cable
should be kept to a minimum.
For situations where noise and interference from the vehicle is excessive, Codan
recommends that you use the Vehicle Interference Suppression Kit (Codan part
number 15-00704).
Related links:
Connecting the battery supply on page 357
Tight electrical
connections
Check for defective cables, loose connections, corrosion, cracked cases or
covers, loose hold-down clamps, and deformed or loose terminal posts.
Table 37: Battery maintenance (cont.)
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