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Topic: Isolator (Read 1066 times) previous topic - next topic

Isolator

I have searched, but could not find on the tech forum recomendations for a new replacement for my 12vdc isolator.

Help?

Re: Isolator

Reply #1 –
It needs be rated for or exceed the amperage of your alternator. 
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: Isolator

Reply #2 –
Quote from: Duane Budd –
I have searched, but could not find on the tech forum recomendations for a new replacement for my 12vdc isolator.

Help?

Like Chuck recommends, meet or exceed your alternator. Look on alternator for model number and then go online for the output. Any doubts, call the distributor with the part number.  Check with RV sources like PPL ( Battery Isolators by Noco - PPL Motor Homes) for a new one.

When you replace, disconnect all batteries, and make SURE all cables are marked. The factory marking may have faded. Mine was replaced and the wrong connections made a year before I bought it and several things did not work. Caused me a lot of head scratching until I figured it out. I used a Brother label machine to mark each one. Makes it a no-brainer to replace.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Isolator

Reply #3 –
You probably have a 160 or 190 amp alternator but you need to check that.  You can look for a 300 amp isolator and that should cover it even if you upgrade later on....I am planning on uprating mine sooner or later.
2025 Wanderbox Outpost 32 on F600 Expedition Motorhome
2015 Born Free Royal Splendor on Ford 550 nonslide version  for sale
Former Coaches  covering. 360,000 miles
1999 34 U270
2000 36 U320
2001 42' double slide U320
2018 Jeep Rubicon

Re: Isolator

Reply #4 –
I always call FT Parts first.  Even if you don't buy from them, you know you're looking for the right thing.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Isolator

Reply #5 –
So why are there 4 terminals on top of the Noco isolator while the one in my coach has only 3?

Re: Isolator

Reply #6 –
Some are designed with two inputs and two outputs. You jumper an input.

It might be time to remind people that Foretravel has transitioned to an electronic isolator on newer coaches. I think Brett brought it up. A bit pricier, it gets rid of the half volt drop as it doesn't use diode.
The selected media item is not currently available. Dave Head & Megan Westbrook
Titusville, FL - The Great Outdoors
'98 270 buying this month
Toad is a 2018 F150 XLT

Re: Isolator

Reply #7 –
Actually, this Brett likes MANUAL.

I use a marine ON-OFF switch rated at 360 amps continuous. Inexpensive and bomb-proof.

Alternator output and chassis battery are on one lug of the switch. House battery on the other log.

Switch off, alternator charges chassis battery (they are hard wired to the same lug).

Switch on, alternator charges BOTH batteries.

WHY:
No voltage drop across a diode-based isolator (turned into HEAT).
No need to subject a fully charged house battery (plugged in overnight and will be plugged in tonight-- not dry camping) to OVER-charging all day. Said another way, no need to burn diesel into power the alternator to subject the house bank to 14.0 or so all day long.
No potential failure of a diode-based isolator OR a solenoid/relay-based isolator.

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: Isolator

Reply #8 –
What is the name of the Foretravel electronic isolator?  A year ago, at the IH-45 announcement, we saw that IH-45 had a big diode style isolator with large curved cooling fins, so that build still used the old style.

I did hear that several years ago Foretravel was selling a marine voltage controlled relay to combine house & start battery banks (to replace Trik L Start type combiner). Anyone know the name of this combiner?

Re: Isolator

Reply #9 –
Quote from: wolfe10 –
Actually, this Brett likes MANUAL.

I use a marine ON-OFF switch rated at 360 amps continuous. Inexpensive and bomb-proof.

I was gratified to read your view on a manual marine-type battery switch. I've used them on boats for 40 years and have been considering something like that myself.

Where did you mount the switch, Brett?

Craig
1993 U225 36' Unihome GV with PACBRAKE exhaust retarder, Banks Stinger and Solar Panels.
Toad: 1999 Jeep Wrangler 2-door soft-top.

"No one has ever had to evacuate a city because the solar panels broke."

Re: Isolator

Reply #10 –
Quote from: wa_desert_rat –

Where did you mount the switch, Brett?

Craig

Craig,

Like you, I had used a simple Perko switch on our sailboats for decades.  I mounted it on the "kick panel" under the forward edge of the bed with the switch easily accessible at the forward edge of the bed.

 I also brought all wiring and relays mounted behind the driver's side mud flap into that area. Labeled all wires, relocated the panel they were mounted on to the "electric compartment" between engine room forward wall and the wall the 120 VAC breaker box is mounted on.  All wires were long enough that no splicing was required.  A MUCH better location for electrical components!
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: Isolator

Reply #11 –
Brett... perfect. Gets all the connections up and out of the worst of the spray in wet weather, too. Thanks. :)

Craig
1993 U225 36' Unihome GV with PACBRAKE exhaust retarder, Banks Stinger and Solar Panels.
Toad: 1999 Jeep Wrangler 2-door soft-top.

"No one has ever had to evacuate a city because the solar panels broke."