Auxiliary Power Outlet: Description and Operation

Power Outlets Description and Operation

System Description

The alternating current (AC) accessory power outlet system consists of the accessory AC/DC power control module and the accessory power outlet. The accessory AC/DC power control module converts 12 volt direct current (DC) battery power to 110-120 volts AC power to operate AC powered devices. The power inverter module within the accessory AC/DC power control module provides up to 150 watts of power. The accessory power outlet is designed to accept two and three prong 110-120 volt power cords. The accessory power outlet provides the usual hot and neutral line circuits. The neutral circuit is isolated from the chassis ground. The center terminal receptacle is empty and does provide a circuit ground.

System Operation

The accessory AC/DC power control module receives fuse protected battery voltage and is connected to the 12 volt electrical system ground. The accessory power outlet has an internal switch, that detects when an AC powered device is plugged into the outlet. When the ignition is ON, and a 120 volt AC powered device is plugged into the accessory power outlet, the normally open switch in the accessory power outlet, closes. When the accessory AC/DC power control module detects the voltage from the accessory power outlet switch, the inverter module begins to supply 110-120 volts AC to the accessory power outlet after a 1.5 second delay. An LED indicator in the accessory power outlet illuminates when the outlet is receiving AC voltage. The accessory AC/DC power system is protected against circuit overload and circuit shorts to ground.

Isolation Fault Protection

The accessory AC/DC power control module contains a ground fault circuit interrupter (GFCI). GFCI monitors the 110 volt AC circuit for the following conditions:

* The hot circuit or the neutral circuit becomes shorted to the vehicle chassis ground
* The current flow through the hot circuit and the neutral circuit differs from each other by greater than 6 mA

If either of the above conditions is detected, the accessory AC/DC power control module will turn OFF. The module remains OFF, until the AC powered device is unplugged from the outlet, and then plugged into the outlet after a 3 second delay.

Overload Shutdown

The accessory AC/DC power control module will turn OFF if the current in the 110 volt circuit exceeds 3.8 amps for 1 second, or 2.5 amps for 10 seconds. The module will turn ON again, when the AC powered device is unplugged from the outlet, and then plugged into the outlet after a 3 second delay.