Univolt FACTS - Page 2

smily · 10-09-2002, 11:47 AM

Concur that indicator light is wired to 12 volt side of converter.

To the Buss to be exact. The battery is also wired to Buss

12 volts on Buss at all times = indicator light on all the time?

attention to Indicator thread. I never did get that one straight.

Glad you are on board Frank.

Smily

FrankR · 10-09-2002, 02:01 PM

A converter is a small version of a battery charger..... Da questions......huh??

Indicator lite is lited by output from converter. Have not research why this lite works ONLY when converter is powered. There may be a diode that prevents any feedback from battery.

Converters are often called "battery eaters". This is because the converter supplied by Airstream is dictated by costs. The more ya pay the better the output regulation. This is known as battery charge taper. As the battery becomes more charged the rate is decreased.

The paramount action for good battery condition and health is owner participation. Battery condition and longivity are closely monitored on the space shettle. That is big time money investment. Add money and many ideas become reality. If everything is automatic in the RV world, go to a motel. Aside from making major control circuits for an Airstream converter, methods of control are manual by the owner. A battery switch for complete disconnect is mandantory.
A battery at rest will lose about 6% capacity per month. After several 50% drawdowns, the battery is good only for it's lead content. I can destroy a battery in just a few days by overcharge or total draw down.
The easiest method of monitoring a battery or even a bank is the use of a digital voltmeter. These meters will reflect the voltage to one tenth of a volt. A fully charged battery at rest is 12.6volts, and a battery 75% discharged is 12.0volts. As can be noticed a little can mean a lot....

davidz71 · 10-09-2002, 02:17 PM

Chuck,
Do you have a control center for your Safari? Mine has a rectangular red lens on the panel to indicate when you are connected to shore power but when the Univolt was replaced with a Magnetek converter there is no extra wire coming from the converter for that purpose. I just plugged a 110 volt analog meter into the nearest receptacle by the kitchen counter and a test device with multiple lights to tell whether you have proper ground/correct wiring. They were not very expensive and I like the little lights that catch my eye.

FrankR · 10-09-2002, 02:19 PM

The wiring from the tow vehicle to a trailer can be many different methods. My method is to get a manual circuit breaker of about 40-50 amps. This breaker is mounted no more than a foot from the battery of the truck. All the wire is #10 standed mtw [machine tool wire].
Wiring from load side of breaker to a bosche style relay with 40 amps capacity with 12 volts coil. After connection to relay wire is routed under vehicle carefully and attached with 1/4 inch hole as insulator and nylon tywraps. The wire is connected to female recepticle as required. The relay may be wired to close either with engine controls or toggle switch with small lite near driver.
Some folks make a connector at rear bumper so as to use blue power wiring to operate a power jack. The predominate reason for power jack failure has been LOW voltage.
Voltage works as a childs see saw. As voltage goes down........amperage rises....... Relay available at Radio Shack.........about $5..

davidz71 · 10-09-2002, 02:20 PM

Frank,
You never cease to amaze me. I see all your electrical devices and it makes me start thinking about doing things to my Airstream's electrical system I have no business doing- LOL.

smily · 10-09-2002, 02:29 PM

Frank,
How does the tow vehicle provide charge to the trailer battery while in tow. Physically I mean.

I understand that the Tow vehicle alternator provides charge to Tow battery and the seven way connector gets voltage from there but how does the voltage get to the trailer battery from the seven way connector?

It would seem to me that this would require a conductor from the seven way connector to the trailer battery. If this is the case, what is the physical path? I believ that mine is via the Buss within the Univolt.

Smily

smily · 10-25-2002, 08:39 AM

I had PM'd Andy at Inland and this was his comments to the question of "can you start a tow vehicle from the trailer battery since the conductors are common.

(Andy says)

"A charge line" should come from your tow vehicle aternator, through a 50 amp circuit breaker, to the connector at the rear bumper. The trailer cable and trailer are wired so that the 12 volt charge line goes to the univolt through a 50 amp fuse, which is located at the univolt. The other side of that fuse goes to the trailer battery. Another 50 amp fuse goes between the univolt output, to the trailer battery. In that way, regardless of where the "charge" is coming from. those circuits are protected.
Starting an engine, draws a very large amount of current, that the internal wiring within the trailer will not support, and neither would the fuses.
If the tow vehicle is electrically connected to the trailer, properly, and the trailer is plugged into city power, the univolt will not only charge the trailer battery, but it would also charge the tow vehicle battery. That however is not valid if your tow vehicle has a battery "isolator."

Just FYI,
Smily

aliensr · 11-06-2002, 12:57 AM

Hi folks, I'm picking up a '69 A/S in the near future. It has a round 7-pin connector with round pins. The new dodge truck I'll tow it with will have the std round 7-pin connector with 'flat' or 'spade' contacts arranged radially. As such I'll need to exchange the A/S connector for a compatable round connector (bought one). I know what the pin out is for the dodge. I don't know what the pin out is for the A/S.
Is the A/S connector I've seen standard for A/s at least up to 1969? I just want to be sure of getting this right so I don't fry something!!!

thanks, Pat

smily · 11-06-2002, 06:54 AM

Wrong Thread but you can get the info at www.Airstream.com under FAQ's. You will need Acrobat to view the PDF.

You dont necessarily have to change out the connector on the AS. Mine has the same setup and I have the Dodge Ram.

My cable from trailer has standars AS round pins on one end and flat on the vehicle end.

Smily

Pick · 11-06-2002, 08:28 AM

I don't know if this would work, but common sense dictatates that it would. How about installing one of those solar charge controllers betwee the univolt charging line and the battery. Note that I said CHARGING LINE. You could not simply install it between the battery and Univolt because, I believe you would be drawing current back through it when the Univolt was off, or during high current draw situations. More research is needed to see if this is indeed a viable solution.

smily · 11-06-2002, 08:43 AM

On my unit, the charging line is the same as the supply line. There are only two wires going between my Univolt and battery, Positive and Negative, respectfully.

I am not sure of what device you are referring but does it function as a DC Voltage regulator?

I was in the shower this weekend listening to the Univolt humming and it occurred to me that auto mobiles use an alternator to charge their batteries and an alternator fluctuates in voltage and typically exceeds 12.6 volts.

The question came to mind, "how does the system prevent overcharge to the battery"?

Aha! Voltage Regulator. I am wondering if I could install a DC Automobile voltage regulator in series between my Univolt and my trailer battery. ( one of the old model external voltage regulators) They are inexpensive and easy to install.

Any auto / electrical / battery authorities out there?

Smily

Inland RV Center, In · 11-06-2002, 09:32 AM

Univolts are self regulating.

Andy
inlandrv.com
airstreamparts.com

chasgould · 04-24-2004, 07:01 AM

Quote:

Originally Posted by Inland RV Center, In

Univolts are self regulating.

Andy
inlandrv.com
airstreamparts.com

My 1976 Argosy Motorhome unit acts as though the coach battery is not connected to the system. I can get all 12 Volt accesorries to run off of the engine battery by turning the ignition key to the accessory position, and all 110 volt outlets work when plugged into a 110 volt outlet. The Univolt is putting out sufficient 12 volt power (13.5 to 16 Volts), but the 12 volt stuff would not work off of the Univolt, or without turning the ignition key to the accessory position.
Then I ran another ground wire from the negative coach battery to the chassis ground, and now all 12 volt stuff will work off of the Univolt, but still no 12 volt stuff when Univolt is unplugged, and ignition key is off.
I suspect that the positive terminal to the coach battery, or the positive side of the coach load, is not properly connected. Is there a battery cutoff switch hidden somewhere that I am not finding, or can I just run another test lead from the poitive terminal to the positive side of the univolt, and should it be fused. Finally, I suspect maybe a bad ammeter, or loose wire in the control panel may be the culprit.
Any suggestions?
Chas

thenewkid64 · 04-24-2004, 09:17 PM

Chasgould,

There was no factory installed cut off switch. A PO may have added one. The wire from the battery box runs from the battery to the fuse panel, thats it. I would check the routing of this wire to see. You could also have some sort of relay that was installed by a PO that acts as a disconnect and it has failed. Continuous duty relays are not cheap, so many folks by the inexpensive ones and they then fail in short order.

Happy tracing!