Thread Tools Search this Thread Display Modes
Old 11-28-2006, 07:45 AM   #1
3 Rivet Member
2007 25' Safari FB SE
Lake Forest , Illinois
Join Date: Oct 2006
Posts: 184
What is an INVERTER

I have a new AS but it did not come with an inverter. I still do not know the purpose of an inverter or if I should purchase one as an add on.I asked the dealer this question but it was not answered in ameaningful manner. Am I missing something that is essential?

woodedareas is offline   Reply With Quote
Old 11-28-2006, 07:52 AM   #2
Site Team
Janet H's Avatar

1964 26' Overlander
1964 19' Globetrotter
Eastern , Washington
Join Date: Aug 2003
Posts: 11,929
Images: 90
Hi - there is a really nice tutorial on the Airstream website about this.

Don't confuse converter and inverter.

1964 Overlander | '08 Touareg V6
Current Project: 1964 Globetrotter

Let's have a polishing party: I'll supply the trailer and buffing supplies. BYOB (bring your own buffer)

AirForums Custom Search
Janet H is offline   Reply With Quote
Old 11-28-2006, 08:16 AM   #3
Rivet Master
RoadKingMoe's Avatar
2001 34' Limited
The State of , Ohio
Join Date: Sep 2002
Posts: 1,605
Images: 23
The CONverter in your new Airstream converts 120VAC from the power company, to run 12VDC appliances and CHARGES the batteries.

An INverter converts 12VDC from the batteries to run 120VAC appliances when you aren't near 120VAC power. It DISCHARGES the batteries, often at a very high rate, because it takes approximately 12 times the amount of current from the batteries as it's supplying to the 120VAC appliance (it isn't 100% efficient, so that's why 12 times instead of just 10).

At its rated output, even a small 500W inverter can drain two fully charged Group 24 batteries to dead in 2 hours or two Group 27 in 3 hours. If you want longer life from your batteries, you'll not discharge them below 50%, nowhere near dead.

It's best to limit inverter usage to only that absolutely necessary.

- Never use one to generate heat, when propane can do the job. Besides space heating, that includes making coffee and cooking.

- Whenever possible, use 12VDC versions of appliances. This often eliminates two inefficiencies, the inverter's and that of a transformer that's going to power the appliances with a lower voltage.

- Note that many appliances, electronics, etc. use a 120VAC wall transformer to supply 12-14VDC to the appliance. You can replace the transformer and cord with a cigarette lighter plug and cord and eliminate two inefficiencies, that of the inverter and that of the wall wart.

- Things like cell phones, handheld radios or GPS units, iPods, etc often have 12VDC chargers available for them. Use them if possible.

- Most notebook computers use DC voltage greater than the 12 supplied by your batteries. Rather than use an inverter for them, you can use a 12VDC notebook computer power supply that uses a DC-DC converter that's less inefficient.

- Many LCD TVs that have an external power supply also use a higher DC voltage, and you haven't much choice but to use an inverter. Just keep in mind, a 100W TV powered by an inverter will be drawing 5 amps out of each of two batteries, and can take them from 100% to 50% charge in only 10 hours.

- The cigarette lighter plugs on the Winegard antenna connection plates are only rated at 8 amps. You shouldn't use more than an 80W inverter in these, even though there are larger inverters with higher wattage (volts x amps = watts) that have lighter plugs.

- Larger inverters should be wired directly to the batteries (through an appropriate fuse) using a heavy gauge wire as recommended by the inverter manufacturer, and it should be as short as possible. Inverters are sensitive to low battery voltage and longer wire runs lower voltage.

Hope this helps,
RoadKingMoe is offline   Reply With Quote
Old 11-28-2006, 09:07 AM   #4
3 Rivet Member
2007 19' Safari SE
Seal Beach , California
Join Date: Nov 2006
Posts: 204
Current from outlets

Thanks for your explanation of inverters; it actually made sense to me, an absolute neophyte to onboard electronics. What I've been wondering is when your AS is NOT connected to shore power, what current, if any, is flowing from the three-prong (120 volt?) outlets in the coach? Are they dead, or does the system provide 12 volt current from the outlet under these circumstances? Second, where can I get a cigarette lighter plug and cord that plugs into one of these outlets?
ESCAPE POD is offline   Reply With Quote
Old 11-28-2006, 09:30 AM   #5
3 Rivet Member
Currently Looking...
2005 22' Interstate
Afton , Virginia
Join Date: Sep 2005
Posts: 226
Current from outlets

I can't speak for Moe, he did an excellent job of covering the old inverter question, by the way.
But, my experience has been that IF the SHORE POWER is not plugged into an AC current source, the 115 volt style outlets have no AC current.
UNLESS, of course, you have an on-board AC motor generator and it is running.
herrgirdner is offline   Reply With Quote
Old 11-28-2006, 09:35 AM   #6
3 Rivet Member
claybags's Avatar
2007 25' Safari FB SE
rio rico , Arizona
Join Date: Jan 2006
Posts: 119
Without an inverter, there should be NO energy flowing in the 120 VAC outlets when not connected to shore power. They are two independent systems( or should be) If any current flows in the 120 ac circuit when on the road, there's a serious problem in the wiring.
Hope that helps.
Cheers, Jeff
2007 Safari 25 FB SE LS
2006 Chev Express 3500 Duramax
Predator tuner
Equal-i-zer hitch
"Home is where the ART is"
claybags is offline   Reply With Quote
Old 11-28-2006, 09:49 AM   #7
Rivet Master
RoadKingMoe's Avatar
2001 34' Limited
The State of , Ohio
Join Date: Sep 2002
Posts: 1,605
Images: 23
When you aren't plugged into shore power, your 120VAC outlets in the trailer are dead, 0 volts, unless as we and many others do, you have the trailer plugged into a Honda EU2000 (or similar) portable inverter/generator. There's no way I'd run one in the morning unless we were the only ones camping there, and even then, as quiet as they are, I'd prefer not to.

A 12 volt outlet looks like those in your tow vehicle, one of which may have a cigarette lighter plugged into it. Not all 12 volt outlets are rated to supply the power for, or can stand the heat of, a cigarette lighter. The only 12 volt outlets in our 34 are the ones on the Winegard antenna connector plates. One is over the credenza behind the curtain, and the other next to the fold-down mirror/TV shelf in the bedroom.

You can get the plugs/cords at Radio Shack. Note that the appliance end may have different tips, and that the + side isn't always in the center. Make sure you match the cord tip with the one on your appliance's wall wart.

Don't be worried about being a neophyte. The first time we stayed in our Airstream was in the middle of a pasture. My wife got up and plugged the coffeemaker into the outlet and nothing. I told her we didn't have power. So she said she'd just heat the water in the microwave. I just shook my head. I heated water in a pan on the stove and poured it through the coffeemaker basket into the pot.

For what it's worth, 12VDC appliances are often not a reasonable alternative to 120VAC ones, especially when it comes to heat. Those 12VDC coffeemakers can take 45 minutes to an hour to brew a pot of coffee, and still take quite a bit of battery power.

Many boondockers and boaters heat water on the stove and pour it through a Melitta coffeemaker. We now use (especially on the boat) a 33 ounce GSI JavaPress and two 16 ounce wide base stainless steel travel mugs. Being coffee lovers, we also grind beans with a GSI Coffee Grinder.
RoadKingMoe is offline   Reply With Quote
Old 11-28-2006, 11:37 AM   #8
Rivet Master
47WeeWind's Avatar
1948 16' Wee Wind
1953 21' Flying Cloud
Denver , Colorado
Join Date: Jul 2003
Posts: 1,139
Images: 20
Electrical memory aid

Originally Posted by woodedareas
I have a new AS but it did not come with an inverter. I still do not know the purpose of an inverter or if I should purchase one as an add on.I asked the dealer this question but it was not answered in ameaningful manner. Am I missing something that is essential?
A simple mnemonic: An inverter INcreases 12 volts dc to 120 volts ac, and a converter CONtracts 120 volts ac to 12 volts dc, all by electrical magic!

Fred Coldwell, WBCCI #1510, AIR #2675
Denver, Colorado - WBCCI Unit 24
Airstream Life "Old Aluminum"
Airstream Life
"From the Archives"
47WeeWind is offline   Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
connecting 110V system to inverter Cruiser Electrical - Systems, Generators, Batteries & Solar 4 07-16-2003 09:46 PM
Trace Inverter and Electrical Surges NEW2AS Electrical - Systems, Generators, Batteries & Solar 3 04-07-2003 06:22 PM
Back to the inverter questions Krazykraut Mechanics Corner - Engines, Transmission & More... 7 12-15-2002 02:32 PM
Installing an Inverter Krazykraut General Motorhome Topics 4 12-08-2002 11:22 AM
Inverter problem Don McKelvay Electrical - Systems, Generators, Batteries & Solar 2 11-03-2002 05:40 AM

Virginia Campgrounds

Reviews provided by

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities

Copyright 2002-2015 Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:31 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2016, Jelsoft Enterprises Ltd.

Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.