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wa8yxm · 08-05-2013, 06:48 AM

If you were using only battery power then I do not know what could have happened.. Provided everything is wired properly.

One thing that can mess you up big time. Inductive kicks. For example a Fantastic fan or the furnace blower suck some major power when running,,, When they shut off strange things can happen.. Current continues to try and flow (Think of electronic inertia) and this can cause voltage spikes epically if you have a long wire run.

I do not **THINK** this is your problem.. but alas I'm running out of ideas.

One other thing.. Often the accessory outlets used in the "House" are a tad "Smaller" and this can compress the negative contact on the plug so it's not making good contact when plugged into the standard size outlet on the dash.

DawnAndChris · 08-05-2013, 08:20 AM

Maybe you can plug a cord into one of the bad outlets and collect voltage data off the end of that.

Maybe it has to do with jiggling the socket... maybe not if it is more than one.

What all devices went bad? How were they ruined?

As you're stating... something HAS to be wrong.

Step back and re-examine the whole problem. If the electric is fine, maybe something else is going on.

Good luck! Keep us posted

vsheetz · 08-05-2013, 08:34 AM

Quote:

Originally Posted by Cobra1

One more comment. You state your inverter is off and it's AC output unplugged but I gather it is still connected to the coach batteries. Jus because it is off does not mean it Is not doing anything as it usually has an electronic switch.

I did not see your response but could have missed it, did you measure for AC voltage across the 12v outlet? If none there then I am stumped and wait for your final find a hd fix.

Last evening before your note i also became aware that the house inverter is still active when turned off and AC output disconnected, just as you comment here. So I disconnected the DC input to the house inverter and have successfully operated devices on the DC power ports in the coach. Looks like may be hot on the trail of the problem.

Cobra1 · 08-05-2013, 12:15 PM

Glad to hear you are making progress. Working on a coach with several different sources of power can be daunting times.

YC1 · 08-05-2013, 06:20 PM

As suggested, troubleshooting with a few lines of type can be difficult. On occasion I have given my phone number to folks that are really struggling. Being able to play "20 questions" will often lead to an important detail that is seemingly not important to the issue. Such as an inverter being on. There was a previous suggestion of measuring for AC but no feedback on that one.

This gang will sort it out.

glarnold · 08-05-2013, 06:44 PM

"This gang will sort it out."

That's what I love about this forum.

Thanks, guys and gals.

GL Arnold

vsheetz · 08-05-2013, 09:12 PM

Worked with it some more today. Don't see a AC component on the DC. Don't see a difference with or without the inverter input side connected. This will my VOM, so may not be conclusive of course.

In reading towards a replacement inverter it appears those with remote switches have a current draw when switched off. I also see where sparking is to be expected when connecting the DC cables. There are capacitors charging soonest connected. As my inverter is 10 plus years old, one wonders if this area could be the problem and somehow causing a transient voltage or current surge to the DC side when a load is changed or introduced. Just speculation of course.

Does not matter the detailed root cause, as a new inverter is in order one way or the other.

HUGE thanks to all for the suggestions and help with this issue.

Vince

Dunner · 08-05-2013, 09:15 PM

Thx for the update. Don't give up.

vsheetz · 08-05-2013, 09:57 PM

Quote:

Originally Posted by Dunner

Thx for the update. Don't give up.

Don't give up?

At thus point I am pretty satisfied the house inverter is the source of the problem and a replacement will resolve the problem.

YC1 · 08-06-2013, 09:08 AM

Still not adding up unless those outlets are connected right at the inverter input and there is some counter emf that is not being filtered due to the long run of wire from the batteries. The other issue is using a digital voltmeter. The meter response is to slow to see a spike. Any chance you can follow the outlet wires to where they are connected.

Are these factory outlets or added aftermarket?

John Hilley · 08-06-2013, 09:20 AM

It appears some AC is somehow coupling to the battery side of the inverter.

vsheetz · 08-06-2013, 09:36 AM

Quote:

Originally Posted by YC1

Still not adding up unless those outlets are connected right at the inverter input and there is some counter emf that is not being filtered due to the long run of wire from the batteries. The other issue is using a digital voltmeter. The meter response is to slow to see a spike. Any chance you can follow the outlet wires to where they are connected.

Are these factory outlets or added aftermarket?

Outlets are factory. They are connected to a bus bar with fuses on a house DC power distribution panel.

Yes, the meter response is of course too slow for a spike or transient.

TQ60 · 08-06-2013, 04:14 PM

OK, so disconnecting the inverter corrects the problem.

NOT SO.

It just STOPS the problem.

The inverter MAY be placing back fed ripple onto the DC side (input), this could be from bad inverter input filter or bad power connections.

What also could be happening is LTS (lazy Tech Syndrome), or CMS (Cheap Manufacturer Syndrome) this is where corners are cut to save time and or money.

The output of the inverter (Black hot and white neutral) should NEVER be common to any 12 volt circuit.

The SAFETY ground also are included in this!

The inverter safety ground should be routed back to the load center and attached to the ground buss bar, then that bar should be solidly connected to the chassis at ONE point.

The outlets are connected the same way, ALL wires brought back to the load center with good solid connections.

Chassis ground connectins for all 12 volt devices need to be clean and solid.

What MAY be happening here is the output from the inverted may be perfectly fine, but traveling where it does NOT belong due to funny connections, say one outlet has a white wire touching ground or some other strange thing.

Stray unwanted current is flowing through the chassis on the ground side, and this is landing on the 12 volt device.

Since the 12 volt device is plugged into the adaptor then it has the 12 volts combined with whatever stray voltage may be on the ground side (or positive side).

So connect everything back to normal and turn on the inverter.

Get a long wire and connect to the ground bar in the load center.

Now measure BOTH AC and DC voltage from that wire to everything involved, the center pin and sleave of the adaptors, loose assemblies that may have ground wires etc, you get the idea?

Only change the inverter if it is bad, I do NOT think it is broken but it is the root of the problem.

wa8yxm · 08-06-2013, 05:34 PM

That might be the issue... I have a very good True Sine Wave in-line inverter (PRosine 2.0) but the charger module has a leaky pass transistor, so it never stops charging (just slows way down).. In my case it cost me a gallon of Distilled (89 cents) but... This can be a problem.

What's worse is the "Kick" when it goes into/out of, inverter mode, which mine does often. (but since it does not charge (I use the Progressive Dynamics for that) and due to the way thgings are wired... That is minimized in my rig.