electically challenged

[wildcat455]

Ok, I admit I'm electrically challenged. But I want to install my own Fantastic Fan. Now here's what I have observed. I've got a vent fan in the rear, it is operated from a ceiling switch 3 in or so from fan unit. It is labeled 'citypower/battery power. Works great but I lost the vent cover on my 'shakedown trip', hence the need for an upgrade unit. The fan uses a transformer. Now, what problems am I looking at electrically speaking here.in the installation of the 12 v fantastic fan.? From what I described can you tell me if I've got 12 power handy? Mike

[59toaster]

Sounds to be be wired the same way as our 59. I have not pulled it appart to confirm this but it appears that the fan motor is 12v. The City/12v switch does just that. The transform in the rear most vent steps down to 12v. You should be able to use JUST the leads going directly to the motor and retain the rest of the wiring as long as that transformer is not in the way of the new vent.

Word of caution is be off shore power and have the Univolt off when your messing with that stuff up there. Back in that time frame they were not that great at keeping the live stuff insulated. and open transformer like that would never fly today. I think that's why they went to 12v on eveything with a central converter. There is another tansformer for the blower on your heater as well up under the cabinet. If you got kids don't let them poke around in that cabinett.

I'm updating ours I'll probably scrap the transformers and go with a central converter.

[wildcat455]

cool, just what I was looking for. I didn't know if the fan moter was 12v or 110. The same setup exits for the kitchen wall vent. I haven't checked the furnace, probably going to just use a pelonius space heater or something till I can afford a new AC with a heat strip.

[wildcat455]

Univolt? what univolt? just kidding, but on my airsteam, everthing was wired double, 12 vold and 110. Two seperate systems. Seems to work ok, I'd like ot keep as much original as I can. Mike

[thenewkid64]

There is only 1 itsy bitsy issue with taking the 12 volt power off that transformer. It is going to be unfiltered or unrectified. I belive Fantastic requires a filtered 12 volt source. They do make them in a 120 volt model if memory serves. You might want to check that power before you cut a bigger hole in your roof.

[71tradewind]

The univolt is rectifed 12 volt dc but not filtered,it uses the battery as a filter ,sooooo if the battery is shot or non exsistant you may have a problem. The Univolts are incredible power supplies and are not cheap to build ,lots of copper in them,but the capacitors on the primary side of the transformer do tend go bad with age ,which can also cause the univolt to generate lots of elec. noise.

[uwe]

If the vent cover is all that's needed, and the fan itself works fine, then you might consider just changing the cover. InlandRV has some of those available.Clear or smoked, I believe.
This would also keep your setup original. Just a thought.
I do like the fantastic fans, I checked them out in the new units. They just seem sooooo plastic to me, could not see them looking right in a 1961.

[wildcat455]

I agree, the plastic does look cheesy, but the twin riser mechanism that the vent attaches to is also damaged. Plus the old motor was awfully noisy. Now to the other issue, filtered and rectified. Not sure I have a clue what you guys are talking about, but i"m gonna assume I"m unfiltered and unrectified(I got rectified the other day when I went for my over 50 physical, but that's another story). I repeat, my unit has no univolt, never had one prob not gonna have one. It does have a new battery and the 12volt system works great. Now, am I gonna have a problem hooking up the 12v fantastic fan motor to the transformer power lead? Thanks for your patience. Mike

[uwe]

You need to check out what voltages and current types you have.
If you don't have a Univolt, then every 12V appliance or device must have it's own transformer. What is keeping your battery charged?
Rectified means that the current is converted from A/C to D/C.
The fantastic fan needs 12V D/C.
You need to get a multimeter and check Voltages, see what you got.
Unless another forum member has a similar setup and chooses to pipe in.
i would not just hook up the fan and try and run it. If the existing transformer does not work for this purpose, then you might be looking at more steps necessary to complete your project than you bargained for.
Take the multimeter leads and check voltage between the wires going to the switch and/or fan. With trailer power plugged in, you will get a reading either on A/C or D/C. If there is a tag on teh transformer, or near it, or perhaps on the fan motor, then you might be able to tell from that.
I am not sure what the term "filtered" means in this application, either.

[drboyd]

....as close as I can tell.

The existing fan motor is an AC/DC motor, and operates on either 12v DC from the battery or 12v AC from the transformer. A transformer will only provide AC, so this must be what you have. This will be a wound rotor / wound stator motor, kinda like the old Lionel trains.

The Fantastic Fan will probably be a DC-only unit, if I had to guess. I would also guess that it's a permanent magnet motor, and thus it will not run on 12v AC. It'll just sit there and hum until all the smoke comes out.

You're kinda stuck here. You'll probably want to re-wire the switch so that only the "battery" position is operative.

[Inland RV Center, In]

The original "Univolts" were a simple transformer with two different output voltages.

One output was 12 volts AC.

The second output was 19 volts AC.

The second output (19 vac) was used to power fans. A 12 volts DC motor will run correctly on 19 vac.

Ohms law says the effective DC equivalent of 19 vac is 13.44 volts, (19 X .70711).

A 12 volt light bulb doesn't care if the voltage is AC or DC. It works the same in either case.

Not so with DC motors that have field windings.

The ceiling vent and stove exhaust vent fan motor that has been used for many many years, is a DC motor, with field windings. That also means you can take the motor apart, reverse the wiring of the field coil, which will reverse the rotation of the armature.

The old style (transformer) Univolt, can easily be replaced with the new style univolt. The major difference is the the new style univolt charges the battery (a transformer cannot) and there is no need to select between "city power and battery power."

Everything is automatic.

Andy

[wildcat455]

Hmmmm, seems I probably have a 12v direct motor with windings. I do not have a univolt, repeat, NO UNIVOLT, never had one. The transformer(s) are at the ceiling vent, the kitchen vent, and the water pump. Andy, sounds like I might be just replacing the vent cover and keeping my original setup. By the way, my new tailights just arrived from InlandRv and look great!
Mike

[wildcat455]

correction....The existing fan motor is an AC/DC motor,

[drboyd]

Yep, it has to be AC/DC. However, the new one will probably be DC only.

[markdoane]

Mike: Did your rectification go OK? I need to be rectified in about two weeks (first time) and I'm a bit apprehensive.
Should we start a new thread?

[drboyd]

...the most important thing to remember is "DON'T SMILE!"

[wildcat455]

Probably not a good idea for a new thread, I'd rather diagnose Airstreams than hear about what medical maladies people may have. However, since you are a first timer to middle age physicals', I'll pass on what my dad told me when I asked him what to expect.......'no problem, just be sure that when the dr is doing the exam he has only one hand on your shoulder not two.

Mike