Specifications

SVI Trucks

Freightliner 4-Door Demo

SVI #917 01/05/15

If a mechanical-type device is used, it shall conform to one of the following SAE standards:

 SAE J156, Fusible Links

 SAE J553, Circuit Breakers

 SAE J554, Electric Fuses (Cartridge Type)

 SAE J1888, High Current Time Lag Electric Fuses

 SAE J2077, Miniature Blade Type Electrical Fuses

Switches, relays, terminals, and connectors shall have a direct current (dc) rating of 125 % of maximum current

for which the circuit is protected.

Power Supply

A 12 V or greater electrical alternator shall be provided. The alternator shall have a minimum output at idle to

meet the minimum continuous electrical load of the vehicle, at 200°F (93°C) ambient temperature within the

engine compartment, and shall be provided with full automatic regulation.

Minimum Continuous Electrical Load

The minimum continuous electrical load shall consist of the total amperage required to simultaneously operate the

following in a stationary mode during emergency operations:

1) The propulsion engine and transmission

2) All legally required clearance and marker lights, headlights, and other electrical devices except windshield

wipers and four-way hazard flashers

3) The radio(s) at a duty cycle of 10 percent transmit and 90 % receive (for calculation and testing purposes, a

default value of 5 A continuous)

4) The lighting necessary to produce 2 fc (20 lx) of illumination on all walking surfaces on the apparatus and on

the ground at all egress points onto and off the apparatus, 5 fc (50 lx) of illumination on all control and

instrument panels, and 50 percent of the total compartment lighting loads

5) The minimum optical warning system, where the apparatus is blocking the right-of way

6) The continuous electrical current required to simultaneously operate any fire pumps, aerial devices, and

hydraulic pumps

7) Other warning devices and electrical loads defined by the purchaser as critical to the mission of the apparatus

If the apparatus is equipped to tow a trailer, an additional 45 A shall be added to the minimum continuous

electrical load to provide electrical power for the federally required clearance and marker lighting and the optical

warning devices mounted on the trailer.

The condition of the low voltage electrical system shall be monitored by a warning system that provides both an

audible and a visual signal to persons on, in, or near the apparatus of an impending electrical system failure

caused by the excessive discharge of the battery set.

The charge status of the battery shall be determined either by direct measurement of the battery charge or

indirectly by monitoring the electrical system voltage.

If electrical system voltage is monitored, the alarm shall sound if the system voltage at the battery or at the master

load disconnect switch drops below 11.8 V for 12 V nominal systems, 23.6 V for 24 V nominal systems, or 35.4 V

for 42 V nominal systems for more than 120 seconds.

A voltmeter shall be mounted on the driver’s instrument panel to allow direct observation of the system voltage.