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Topic: Dualling isolators? (Read 640 times) previous topic - next topic

Dualling isolators?

It wasn't me ok!  But WTH???

'93 U280
Curtis and Wendy and the baby tortoise SloMo
1993 U280 grand villa
Planes and cars
Boulder City, Nevada

Re: Dualling isolators?

Reply #1 –
That is strange. The only reason that I can see is the alternator is bigger than 200 amps and if
that's the case why not put in a higher amp isolator.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Dualling isolators?

Reply #2 –
These appear to be wired in parallel. Nothing wrong with that, 2X the current capacity. What is the alternator current rating, maybe a previous owner installed a larger one?
Peter and Tammy Fleming
1991 U300 GV 40 - Sold, owned for 4 years
Downsized to Roadtrek Popular 210 class B

Re: Dualling isolators?

Reply #3 –
Hum. Ok it seems my alternator is a prestolite 160 amp and the isolators are 120 amp each.  Were our original alternators less amperage?  Would it be a good idea just to put a 200 amp isolator in now and have less failure points?  Recommendations? 

Also seems my WFCO 65a power converter isn't wanting to power up for mare than a second or two.  Removed it, but it's riveted up, so can't open it to mess with it. I guess I should make separate post about that. Those converters simply turn 110v to 14 v to charge batteries?  So installing a prosport6 promariner charger which I have could make up for it? ?????



Curtis and Wendy and the baby tortoise SloMo
1993 U280 grand villa
Planes and cars
Boulder City, Nevada

Re: Dualling isolators?

Reply #4 –
Yes, isolator rating should be the same or higher than alternator amp output.

Still trying to wrap my head around why TWO???

To me, the extra complexity and cost is sure not worth it.

Short term workaround for a failed battery isolator is stupid simple:  Merely move all wires (B+ from alternator, wire to chassis battery and wire to house battery) all to one lug.  Both banks charged-- no possible failure point related to battery isolator.  BUT, be sure to return them to their original location or both banks will discharge as one with engine off and no shore power/generator.

Assuming you don't have an inverter/charger, just the converter.  Let us know.  If just the converter and it has failed, be sure to get a "smart"/3 stage converter or charger. And, I would suggest at least 60 amp capacity for those times you are running the generator to charge the batteries.  And, 80 would be better.  If no/little dry camping, then 40 amp smart model would be adequate unless you use a lot of 12 VDC or have/plan on having a separate inverter that will take amps from the battery.  And, if that is the case, lots of good quality inverter/smart charger combinations.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Dualling isolators?

Reply #5 –
My original post I assumed you had an alternator over 200 amps as the isolator that had come
with the coach was 200 amps and as Brett said why go to all that expense and work to make
it more complicated. My inverter charger charges 125 amp and I wouldn't mind if it charged
200 amps or more. 
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Dualling isolators?

Reply #6 –
Quote from: wolfe10 –
Yes, isolator rating should be the same or higher than alternator amp output.

Still trying to wrap my head around why TWO???

To me, the extra complexity and cost is sure not worth it.

Short term workaround for a failed battery isolator is stupid simple:  Merely move all wires (B+ from alternator, wire to chassis battery and wire to house battery) all to one lug.  Both banks charged-- no possible failure point related to battery isolator.  BUT, be sure to return them to their original location or both banks will discharge as one with engine off and no shore power/generator.

Assuming you don't have an inverter/charger, just the converter.  Let us know.  If just the converter and it has failed, be sure to get a "smart"/3 stage converter or charger. And, I would suggest at least 60 amp capacity for those times you are running the generator to charge the batteries.  And, 80 would be better.  If no/little dry camping, then 40 amp smart model would be adequate unless you use a lot of 12 VDC or have/plan on having a separate inverter that will take amps from the battery.  And, if that is the case, lots of good quality inverter/smart charger combinations.

I only have the taytronics inverter that I understand is the original with the coach.  All it does I believe is convert the 12v to 115v.  Picture attached. 
Curtis and Wendy and the baby tortoise SloMo
1993 U280 grand villa
Planes and cars
Boulder City, Nevada

Re: Dualling isolators?

Reply #7 –
I would replace it with a new 2800 Magnum inverter-charger. It will charge your house batteries and also provide pure sine wave 120 power.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Dualling isolators?

Reply #8 –
I think I'd be inclined to get a new isolator, some wire of various sizes, and install the isolator and related electronics up under the bed.

You don't say what year your coach is (hint: put it in your signature) but our 1993 had the isolator located behind the duals, and I moved it up 10 years or so ago. MUCH better arrangement. Foretravel made (and still makes) some great coaches, but not all of their ideas were well thought out. That was one of them.

As Ron said above, replace that old inverter with a modern one. Yes, your back will complain when you are removing the old one, but it only hurts for a few days. <grin>

Re: Dualling isolators?

Reply #9 –
Quote from: red tractor –
I would replace it with a new 2800 Magnum inverter-charger. It will charge your house batteries and also provide pure sine wave 120 power.
Or ... perhaps the  hybrid 3012 magnum inverter / charger. It is supposed to help the 110 with battery power if your plugged in and shore power ( 15 or 20 amp ) isn't getting it done.  I haven't had many opportunities to test that but i like the concept and not a lot more $$$
Robert and Susan
 1995 36' 280 WTBI 8.3 3060r
 1200 watts on the roof, 720 Ah of lithium's
 Build # 4637. Motorcade # 17599
        FMCA  # 451505
        18  Wrangler JLUR

Re: Dualling isolators?

Reply #10 –
Actually, the right answer (in terms of capacity and cost of replacement equipment) depends on: how the OP will be using the coach, how long they plan to keep it and how much $$ they want to invest.

There is no single answer that makes sense for everyone.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Dualling isolators?

Reply #11 –
What would the more modern inverter do for me?  I do not have a residential fridge and can run mine off of propane.  My tank is giant. And all I really need 110 for while boondocking is the woman's blow dryer and maybe occasionally the micro or tv, and it seems the generator can handle what my inverter won't. Powering the AC units?  Wouldn't that be too large a need for house batteries?
Genuine question....Im new to all this.
Replaced my converter/charger, isolator, solenoids, breakers and relay.

My inverter seems to work fine



quote author=kb0zke link=msg=479156 date=1701830955]
I think I'd be inclined to get a new isolator, some wire of various sizes, and install the isolator and related electronics up under the bed.

You don't say what year your coach is (hint: put it in your signature) but our 1993 had the isolator located behind the duals, and I moved it up 10 years or so ago. MUCH better arrangement. Foretravel made (and still makes) some great coaches, but not all of their ideas were well thought out. That was one of them.

As Ron said above, replace that old inverter with a modern one. Yes, your back will complain when you are removing the old one, but it only hurts for a few days. <grin>
[/quote]
Curtis and Wendy and the baby tortoise SloMo
1993 U280 grand villa
Planes and cars
Boulder City, Nevada
 

Re: Dualling isolators?

Reply #12 –
MultiPlus-II 2x 120V - Victron Energy

This is what I put in mine. The Taytronics was not functional. This replaced the inverter and the converter charger. The Taytronics is a modified sine wave. Some of the newer electronics have issues with that because it's not a pure sine wave. The Victron handles everything in my coach. I'm running mini splits and a residential fridge, so the AC loads might be different for you. It can also split the load if you have a low current shore power and pull some from shore and some from the house batteries. It depends on when you need the 120v AC really. If you are fine with running the generator for AC, then it's not a big deal and your inverter loads won't be very high. This thing is a great at charging the batteries too. I like it because it will auto transfer between batteries and shore/generator power. So I don't have power interruptions when I unplug. Boondocking with full HVAC and no generator requires some good battery capacity and a bunch of Solar. It can be done if needed and that's what you want to do.
1991 U300 Side Aisle 6V92 Silver #3897
2004 U320 40' #6246