Community Forums

tym · 06-28-2014, 09:39 PM

On a prior post i got some good info from B Flinn.
I'm starting a new thread because I have narrowed my ignorance some.
I located the power in for 120AC (hidden from the likes of me) in the bumper and the 12 volt system powers fine from the converter.
With all fuses out of the fuse block the converter provides 13 volt to all circuits that have a completed switch ON including 13 volt on a single large fuse gap (fused 40amp)
With converter off AC there is no power across the fuse gaps for any of those switched circuits and the 40 amp fuse gap shows 4 volts. I am guessing that is something feeding back from battery + thru the converter when converter is off ? Does anyone have a real explanation?

In the battery compartment there is a box with finned aluminum extruded body. It has heavy guage + red input direct from the + battery (not switched through the auxiliary solenoid that jumpers to engine). The box has a far post that is heavy guage black line that has continuity to battery neg. And a middle terminal post that is red also heavy guage.
What is this box for? Is it some sort of switch that is supposed to automate switch over to battery while off shore (therefore off converter)? Is this component relative to my problem?
I am on the verge of setting a manual switch to jump from the input red to the middle post red...and see what happens But I wish I knew what the box is/was/isn't doing. Has anyone been there?
Tym

hometool · 06-28-2014, 10:02 PM

the device you are asking about sounds like the isolation diodes that keep you from running the chasie battery dead while camping using battery only

BFlinn181 · 06-28-2014, 10:27 PM

If you google 'battery isolator' I think you'll find an image of what you're describing. They are supposed to keep chassis and house batteries separate from each other unless a charging current is detected. If you're reading 4v with no charging current, your's could be faulty.

tym · 06-28-2014, 11:17 PM

So I can see value in a protection or isolation from excessive drain down, but this is a fully charged battery that is not providing any power across any of the 3 fuse gaps to circuits which have on-switched lights.
Is this "isolator" box suppose to provide a switch function when converter is unpowered?
If it is just a comparator of some sort between chassis and house battery, then the middle +red must have continuity to the chassis batter cable (which is missing).
Could this mean that there is a switching function and I have to have a chassis battery installed for the switching to allow house battery to power up the 12v fuse block? Duh?
Thanks Tym

ahicks · 06-29-2014, 05:44 AM

Tym, it sounds like you have a charged house battery and you can't get your inside lights to work when you aren't on shore power?

If that's the case, you might try following the positive lead from that battery to see if there's not a relay or some sort of switch in it, used to prevent a drain on the battery when it's not in use?

Is the ground wire from the battery appear to be intact, lead to something solid that can supply a good ground?

The finned thing you're describing in your first post, if it's what I think it is, has to do with charging the batteries with the engine running. The center terminal leads to the alternator, outside leads to main and aux. batteries. It will not likely be any part of a problem supplying power to the coaches interior. You should look into what it is and how it works so you better understand it to head off/troubleshoot problems at a letter date.

tym · 06-29-2014, 07:08 AM

Yes the problem is charged house battery but no positive continuity back to the 12v fuse block. Negative continuity is present .
The finned body in the battery compartment must be an isolator and I need to check out a tiny little relay looking think that is fixed onto the plywood base of the converter residing in the closet zone near the fuseblock.
I found a document that discusses differences in the role of an isolator compared to a charging relay
Battery Isolators and Automatic Charging Relays - Blue Sea Systems
If I have both I can see lots of potential for the law of unintended consequences when a feature becomes a liability in a certain configuration.
So I will probably go through the exercise of adding a chassis battery.
And maybe this little relay looking thingy is the culprit... all by itself.

More testing this way and that and I will report back
Thanks
Tym

ahicks · 06-29-2014, 07:38 AM

Tym, chassis battery should not be necessary for interior lights to work.

BFlinn181 · 06-29-2014, 10:16 AM

I think you need to trace 12v (+) from battery to fuse panel. There could be a fusible link, solenoid, or other break in the path of the power. You can use a straight pin to pierce the insulation if ends aren't easy to access. Also check the converter/charger for a circuit breaker or fuse on the outside of the 'box.'

How long after unplugging did you read the 4v? I'm wondering if a capacitor could have been the source.

Dave78Chief · 06-29-2014, 04:31 PM

Do you have a fuse panel that looks like this?

And a converter that looks like this?

If so, then look at pdf page 14 of this for connections: http://www.irv2.com/forums/attachmen...4&d=1296073924

That ferroresonant transformer design of the Triad converter is a bit different. Because of the transformer feedback design, the normal 13.6VDC rule of thumb for early converters does not necessarily apply. Output voltage for this style of converter varies from 12VDC to 14.1VDC depending how much load it sees on the output. Higher voltage for lighter loads.

Dave

tym · 06-29-2014, 05:42 PM

Yes that is a picture of my fuse block, but the converter is different looking .
the Right side of the block is a bus bar that is the + side of the fuses (if I recall correctly) and the left side are individual circuit lugs being the - side.
With converter powered on all fuse gaps have 13 volt and pulling the AC power to the converter all 15A circuits go dead but the large 40A gap at the top changes to 4 volt (cant recall the polarity)
my goal is to learn is not just why there 4 volts at the big fuse but the lack of automatic switching to provide 12volt house battery to the entire + bus bar.

Thanks for your document link, it verifies that the bus bar on the 12v is the + side presumably the 40 amp circuit is for charging only...

The document also confirms that the middle post on the battery isolater is to alternator (and not to the + of the chassis battery)
I need to confirm how my isolator is wired compared to the small diagrame since the isolator functions as a switch (a pair of switches I guess) at some threshold of voltage . One of the outside post is straight to house battery+ but tomorrow I will trace the other outside post.
Tym

Dave78Chief · 06-29-2014, 09:44 PM

If that is not the type of converter you have then I would need to know the Mfg and Model in order to determine if it will work for that style of fuse panel. Many modern converters (e.g PD9245) will work ok. Some though were not designed to be installed like the ferroresonant transformer converter design in the picture (TU-540).

Dave