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Another Fantastic Fan Problem.
My wife told me that I should started thread. Here it is.

In my 2015 mid-bath, the Fantastic fan in the rear shares the same 15 amp circuit with the 12V outlet next to the TV. I have a 150 watt inverter plugged into the 12V outlet to power the Directv receiver. The Directv receiver only draws 55 watts.
The problem is that when the Fantastic fan is turned on, the inverter goes into a low-voltage alarm.  This happens even with a replacement inverter. I measured the voltage drop only to 11.0 volts which should not bring in the alarm. Any ideas how to trouble shoot?
I had call customer service for the Fantastic fan just to see if they had any experience with this type of problem. I was treated very badly by a gal who had no idea, and she said it is their policy not to let anyone talk to a tech. She wanted me to send an email.  Great customer no-service.
2105 MB

Re: Another Fantastic Fan Problem.
Reply #1
There is no problem with the fan. You are asking too much from a 12v outlet so far from the battery on thin wire.
I am sure someone will post the numbers, but the deal is you can not have it all. Toss the TV and go outside.  ;D
Don & Dorothy
Sold our LD in June of 2023

Our boring always non-PC travel blog
Traveling Dorothy

Re: Another Fantastic Fan Problem.
Reply #2
Long 120V wires are better than long 12V wires in this case.
You could also look for a more-efficient inverter, or a more-efficient DTV receiver, but those adjustments may not be enough to get you there.

Chip
2000 Front Lounge

Re: Another Fantastic Fan Problem.
Reply #3
Does the fan have the old-fashioned speed control, with the resistor pack, or something more efficient?

Mark H.
Former owner, 31-foot gas Class A
Former owner, 1997-8 mid-bath

Re: Another Fantastic Fan Problem.
Reply #4
OK, I did the math. The "only 55watts" the Directv receiver uses is 4.6 amps. Trivial for 120v, significant for 12v. The fan uses 1.5 amps on low speed. Combined, that's 6amps from a 12volt outlet that can deliver 10 amps max when close to the battery.

I try to purchase only items that run on 12v, which eliminates the need for an inverter.
That said, I have an inverter close to the batteries and run a 120v line to where I need AC.
Don & Dorothy
Sold our LD in June of 2023

Our boring always non-PC travel blog
Traveling Dorothy

Re: Another Fantastic Fan Problem.
Reply #5
OK, I did the math. The "only 55watts" the Directv receiver uses is 4.6 amps. Trivial for 120v, significant for 12v. The fan uses 1.5 amps on low speed. Combined, that's 6amps from a 12volt outlet that can deliver 10 amps max when close to the battery.

I try to purchase only items that run on 12v, which eliminates the need for an inverter.
That said, I have an inverter close to the batteries and run a 120v line to where I need AC.

I've always hated math when it disagrees with what I want to do ...... grrrrrrr
personal fine art photo stuff
TF Mack | Flickr
It's all good .......
2014 Twin King

Re: Another Fantastic Fan Problem.
Reply #6
Update on my problem-
I feel I have a loose connection to my 12V outlet. Please let me if you agree.
The voltage drop at the main fuse panel when I only turn on the fantastic fan to high speed is from 12.6 to 12.5. So I believe the fan is okay.
When I check for voltage drop again with only the inverter on with 55 watt load, the inverter goes into alarm and I can not read the voltage drop. The inverter works fine at the 12V outlet above the dinette table.

Now while doing all of this, the inverter now goes into low voltage alarm by it's self without the fan being on.
I have soldered the slip-on connectors behind the 12V outlet and shorted  out the off/on switch for the 12V outlet to no avail. So the problem is somewhere else back on the feed.

I think the next connection point would be in the cabinet that has the 12V outlet under the cabinet bottom. Does anyone have knowledge of the wiring route?
2105 MB

Re: Another Fantastic Fan Problem.
Reply #7
Hi Wyatt, (is that your first name?) The 12v cigarette lighter style plug, as part of the TV amplifier switch, isn't really rated for a 200 watt capable inverter. While the inverter may only average 50 watts delivered, when it is switched on, momentary inrush current could be much higher. The fantastic vent fan motor, also sucks power until the back EMF, as the fan reaches speed, stabilizes the fans current drain. That is what is shutting down the inverter. A capacitor, or properly placed choke, could stop this interaction. Just placing the inverter in a different plug, as you did, solves this situation. I added extra 12v outlets on a separate circuit to feed accessories next to my TV outlet plug, and into my driver side storage compartment. I added lights in there also. (My TK TV stand is right there) RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: Another Fantastic Fan Problem.
Reply #8
This is a follow-up to give the root case problem of my inverter going into low voltage alarm. For my 2015 mid-bath, of course there are the two 6 volt AGM batteries in series. Even though the batteries are less than two years old, one of the batteries went bad and would not hold a charge. As a result, I had next to nothing for 12 volt current capacity.  Both batteries have been replaced. I lost more of what little hair I have left on my head.
2105 MB

Re: Another Fantastic Fan Problem.
Reply #9
Hi Wyatt. Sorry it took so long, but thank you for letting us know the resolution. Nearly open but not quite problems inside of a battery can be really hard to diagnose. Especially one that new. RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: Another Fantastic Fan Problem.
Reply #10
Wyatt, before you get too comfortable, Don was mostly right but he didn't mention a step.  If the DirecTV receiver draws 55 watts at 120 volts, that is only 0.46 amps but if you are using an inverter to jump from 12 volts to 120 volts, that 0.46 amps jumps to 4.6 amps. Thus, as he said, the 120 volt part is an insignificant load at 0.46 amps, but at 12 volts, it becomes 4.6 amps and is now significant.  When you run those 4.6 amps plus the draw for the fan through a long, small wire, your voltage drops, your amperage climbs, and there is not enough juice to do the job.  Add in poor batteries, and the inverter quits.

Your best bet, long term, is to place the inverter closer to the batteries and use 120 volts for the longer wire run to the DirecTV receiver.

Ken F in NM
'08 MB

Re: Another Fantastic Fan Problem.
Reply #11
May I suggest a voltage stabilizer. Solves the 12 volt voltage drop problem.

Amperor Auto Surge Protector ADP-90DC

I assume it is still for sale.
Harry 2006RB

Re: Another Fantastic Fan Problem.
Reply #12
A couple of things about the Amperor voltage stabilizer's specs caught my eye. First, it claims to have "> 80%" efficiency. That means it wastes nearly one amp in five. And second, the maximum load it can handle is "5.6A 70W Max." That's not much. Just something to keep in mind before you start hooking up a bunch of 12 V devices to this $77 gadget.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"

Re: Another Fantastic Fan Problem.
Reply #13
Yep, works for me. One of them powers the satelite receiver and TV, another powers the inverter that powers the DVR or Blu-Ray player. Without them there would be very little TV watching without shore power or generator.

Voltage with no drain at the 12 volt TV power receptacle is 11.6 with a full battery. The TV signs off at 11.4 volts (maybe it is 10.4 volts, can't remember.) Without them I cannot even watch a complete DVD without the electronics signing off. Add a furnace into the mix and things are even worse. That explains why so many run generators till bedtime.

On an RB the power goes from the battery to the power panel, probably ten ft, then to the TV, probably 20ft. There isn't much margin left when it gets there. Going direct from the battery to the TV with heavy gauge wire didn't help much but I tried.

The sat TV receiver says it works down to 9 volts but it does not. Now things work all evening. I do need to charge back up the next morning. Whether Amperor or something else a voltage stabilizer is required for me to be off grid, and I am always off grid. Needless to say, a vent fan needs to be on a separate circuit.

I have 225 amp-hours of battery and 200 watts of solar. Not enough, but we have made it work. Contrary to the spec I find the Amperor output voltage to be a steady 12.8 volts.
Harry 2006RB

Re: Another Fantastic Fan Problem.
Reply #14
"On an RB the power goes from the battery to the power panel, probably ten ft, then to the TV, probably 20ft. There isn't much margin left when it gets there."

That depends on the gauge of wire that LD used. According to my favorite voltage drop calculator, if they used AWG 10 wire, then the voltage drop in a thirty-foot run would be 2.6%. If AWG 12, then 4.2%. A fully charged battery bank should be at about 12.7 volts, so at the other end of that thirty-foot run one would expect to see about 12.4 V for 10-gauge wire or or 12.2 V for 12-gauge wire.

Assuming fully charged batteries at 12.7 V, 11.6 V is a 9% voltage drop--more than twice as much as one would expect in this situation. (Unless of course your batteries were correspondingly low... but you said they weren't.) That raises the question: what was the voltage at the house battery terminals when you saw 11.6 V at the outlet? In other words, what was the actual voltage drop?

"Going direct from the battery to the TV with heavy gauge wire didn't help much but I tried."

Going direct (hopefully with an inline fuse) was a good way to eliminate variables. But there are still some unknowns here. What gauge wire did you use? How long was the run? And again, what was the actual voltage drop between the house battery terminals and the end of your heavier-gauge run?

One last comment about efficiency: you said "another [voltage stabilizer] powers the inverter that powers the DVR or Blu-Ray player." So you have an 80% efficient stabilizer feeding into a (probably) 90% efficient inverter, for an overall efficiency of 72%, if  I did the math right. Now you're throwing away one amp in four. I can't help thinking there must be a better way. Getting a decent voltage to the TV seems like the clean solution.
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"

Re: Another Fantastic Fan Problem.
Reply #15
I know the theory, I know the math, I also know that a fused 8 gauge wire from the wire exiting the battery box to the 12 volt entertainment outlet shows a 1.2 volt drop with no current as measured by a Fluke meter. Don't know why. Of course the voltage drop is greater once you start using 3-5 amps.

With voltage stabilizers there are no more screaming inverters, the TV never turns itself off and at the end of the evening I still have a state of charge above 80% and never have to run the generator in the evening. Efficiency takes a back seat to utility.

With a dedicated battery charger I do have to run the generator for an hour in the morning to get to 90% charge so solar can top it off.. Works for me and I recommend it to anyone that has screaming inverters and TVs or computers that turn off.
Harry 2006RB

Re: Another Fantastic Fan Problem.
Reply #16
Sounds like a bad ground to me. It takes two to tango, you need an equally beefy #8 wire from the grounded (-) side of the battery to your television. You also should have exactly the same voltage at the battery as you do at the TV with no current flowing. (negligible current from meter as the load). With no current flow, there is no voltage drop. RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

Re: Another Fantastic Fan Problem.
Reply #17
" You also should have exactly the same voltage at the battery as you do at the TV with no current flowing. (negligible current from meter as the load). With no current flow, there is no voltage drop."

Yep, that is the theory but it didn't work that way and I got tired of trying to figure out why.  Don't know where the 1.2 volt drop is coming from and I'm enough of an EE to know it shouldn't be there with no current flow, but it is. We tried several ground points for the meter. Obviously I'm missing something.

Everything works fine with the voltage stabilizers. I now have a lot of sympathy for Edison trying to electrify New York City with DC! I couldn't even electrify my entertainment center! 1.2 volts is too much off the top to make things work for any length of time.

Back to the first post, the voltage stabilizer will solve it with no wiring changes. You will have to change the output connector. Changing it to a female 12 volt receptacle will solve all your problems other than coming up with the $77. You can then use that same cable to run your computer with low coach batteries. It is a handy option to have around.
Harry 2006RB

Re: Another Fantastic Fan Problem.
Reply #18
This whole scenario sounds vaguely familiar. Some time ago (perhaps a year or more) an LDO member had a phantom battery drain and had a tech finally track it down.

If I remember correctly, a switch had been placed in the overhead bunk to control one thing or another. Once the switch had been turned off the battery drain was eliminated.

Sound familiar, anyone? Perhaps there is a hidden switch somewhere that has not been detected.

Just a thought.

Kent
2015 27' RB "MissB.Haven"

Re: Another Fantastic Fan Problem.
Reply #19

"Yep, that is the theory but it didn't work that way and I got tired of trying to figure out why.  Don't know where the 1.2 volt drop is coming from and I'm enough of an EE to know it shouldn't be there with no current flow, but it is. We tried several ground points for the meter."

I can't help but think something very simple is wrong, a bad crimp or wire connection.
The stock wiring should be more than adequate for your power demands.
Have you checked the circuit's fuse for corrosion and tightened the fuse's wire connection screw, in the Power Center?
Check all the Power Center's wire hold down screws, they do loosen.
Make sure to disconnect the 12-volt and 120-VAC power first.

I would have to do a lot troubleshooting before I would spend $150 on voltage stabilizers, they are band aids for an unfound problem. This not normal or common in LD's.

Larry
Larry
2003 23.5' Front Lounge, since new.  Previously 1983 22' Front Lounge.
Tow vehicles  2020 Jeep Wrangler Rubicon, 2001 Jeep Cherokee
Photo Collection: Lazy Daze

Re: Another Fantastic Fan Problem.
Reply #20
"Sound familiar, anyone?"

Yup, that sounds like an Andyism, better ask him.  ;)
Steve S.
Lazy Bones & Cedar
2004 30'IB (Island Bed)
Yesterday is History, Tomorrow is a Mystery
Live for the day!

Re: Another Fantastic Fan Problem.
Reply #21
Hi Kent. That was Lynne Broyles-Greenwood, with a previous owner's modification to the reverse light circuitry. The unknown switch was to turn on the lights from the sleeping area, and also involved a bad relay under the hood. 9-4-16 3:13PM .
   Moral of that story; I always document wiring changes, switches, just so I can remember what it was I did to myself.  RonB
RonB (Bostick) living in San Diego
Original owner of "Bluebelle" a '99 TKB

 
Re: Another Fantastic Fan Problem.
Reply #22
Ron,

Thanks. Keeping a log of any mods or repairs done to an item is a wise course of action.

As the years roll by, it becomes more difficult to keep track, mentally, of the sundry things we do from one day to the next. At my day-to-day, I use “composition” books to log repairs I perform on over 40 pieces of equipment. For my LD travels I keep an extensive checklist of all my gear.

LDO has the “bookmark” function that I utilize on occasion to keep track of significant topics and repairs. If I can remember to do so. 😰

Kent
2015 27' RB "MissB.Haven"