Electrical System - Airstream Excella 500 1973 Owner's Manual

Electrical System
The exclusive Airstream Univolt System
enables you to use the lights and appliances
whether operating on self-contained battery
power or hooked up to 120 volt city power.
This combination unit is designed for pro¬
tection from damage up to and including a
dead short. The 12 volt light bulbs give off
the same light as regular household bulbs, so
that when operating on self-contained battery
power, everything works normally except the
120 volt convenience outlets and electrical
operation of the refrigerator.
Convenience Outlets for 120 volts and 12
volts are located throughout the interior of
the trailer, see diagrams page 60. Exterior
outlets for 120 V are located on the curbside
exterior wall, aft of the main door.
When operating with city power, make very
certain that the service is 120 volt and not
220 volt. Roll out the power cord from the
automatic reel to the desired length and plug
it into the city power source.
The univolt system has a new transformer
designed to maintain constant output voltages
regardless of the variances that occur in city
power systems. The transformer design elim¬
inates the need for complex electronic sensing
systems to charge the battery, minimizing the
possibility of failures and greatly increasing its
overall reliability.
When the three pronged plug can be used,
there will be no problem with proper polarity
120 Volt Exterior Outlet
or grounding. In some older parks and other
locations where three pronged outlets are not
available, take certain precautions to insure
proper grounding and polarity:
1. Attach the three pronged plug to a two
prong adapter. The third conductor line of
this adapter has a short wire lead which is
the ground line.
2. If possible, clamp the ground line to the
junction box or to a water pipe, and then
insert the two prong plug into the recep¬
tacle.
3. Check the polarity light located above the
water heater access panel on International
models and to the roadside of the license
plate on Land Yacht models. If it is on,
pull out the plug, turn it over and reinsert.
The light will now be out.
When no water pipe is available, experienced
trailering people will drive a metal rod two
feet into the ground and attach the ground
120 Volt Inlet
lug to it thus providing the unit with proper
grounding.
The polarity warning light indicates improper
polarity and it should be off when the power
supply cable is used with a two pronged
adapter. It may occasionally glow when the
three wire system is in use, but your trailer is
properly grounded, and in this case you may
ignore the light.
To operate self-contained, simply disconnect
the power supply cable from the city power
receptacle. Store the supply cable in the hose
storage compartment.
When your Airstream is hooked up to 120
volt A.C. the Univolt System automatically
charges the trailer battery and, if it is hooked
up, your automobile battery as well. The
speed and degree of charge depends on how
much power is used for lights and appliances,
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