Replacing an old converter ... what could I have messed-up?

[elmer]

Originally Posted by elmer

PM4 connected overnight ...
12.9V DC output, with 0.12V AC ripple on the DC output terminal.
I didn't test to see if the unit was warm this morning, but will check tomorrow morning.

Here are this morning's readings.

PM4 connected overnight ...
12.9V DC output, with 0.06V AC ripple on the DC output terminal.
15W steady AC draw as measured by a Kill-A-Watt, and the PM4 is warm, but not enough to trigger its cooling fan.

The PM4 seems cooler than last night, but that's almost-certainly just because of the cooler morning air.

Originally Posted by HiJoeSilver

Out on a limb here, check the polarity of the 120v outlet that the converter is plugged into.

Thanks for going out on a limb, I don't think that there are any "bad" ideas at this point.

I just checked the AC socket in the wall, and it's wired correctly, so that's not the problem.

Originally Posted by AHam

Not sure about the PM4, but I used a very similar set up on my '71 Overlander, converting from the original Univolt to a IOTA DLS55 with a separate fuse panel, and it shows that the 50 amp circuit breaker should be located on the +ve battery line. That's how I installed mine and everything is running smoothly. I've attached the diagram for reference.

That's the same circuit diagram that's on Randy's bestconverter.com website.

I can switch the circuit around so that the 50A fuse is on the battery +ve instead of the battery -ve and see if it makes a difference.

I took a photo of the old TW331-W Univolt's connection on its box, and it certainly looks like the old TW331-W was using a fuse in the battery +ve line.




I'm not sure why the old Univolt circuit had a 50A fuse in both the battery +ve in the Univolt, and a 50A fuse in the battery -ve on the Argosy wall.

Originally Posted by AHam

I also ran the ground lug from the IOTA to the frame of my access door with a simple terminal cap and screw.

Unless I'm missing something, that should be the same electrical connection as the Argosy -ve (the white wire).

I really need to connect that ground lug on the PM4 and see what happens!

[elmer]

Originally Posted by elmer

I'm still confused as to whether I should be connecting the PM4's front ground lug to the ground terminal bus (i.e. Argosy negative) in the FB9, or not.

Since things still aren't working properly, then I guess that I'll have to try that tomorrow.

Amazingly (to me), this is the one, very simple thing, that actually seems to solve the problem with my Amazon-purchased PM4 (so far).

It's been charging and working fine for a few hours now.

Currently, the shore power is connected, and the battery has had its top-up charge.

Once I connected the PM4's front ground lug to the FB9 fuse-panel's -ve power bus I got ...

Fuse-panel DC reading on battery (AC shore-connection unplugged) ...
12.5V all house lights off.
12.0V all house hights on.

Fuse-panel DC reading with PM4 just connected to shore power ...
14.5V all house lights off, started with 90W AC draw as registered by the Kill-A-Watt, and rapidly fell to 46W which seemed steady for a long time as it topped-off the battery.

Fuse-panel DC reading with PM4 connected to shore power for a few hours charging the battery ...
13.4V all house lights off, 19W AC draw as registered by the Kill-A-Watt.


That's with this wiring layout (please forgive the blurriness) ...

Originally Posted by bbdo

DC ground has nothing to do with AC ground. Not sure if this is the problem but you definitely want everything properly grounded.

Originally Posted by AHam

I also ran the ground lug from the IOTA to the frame of my access door with a simple terminal cap and screw.

It looks like you guys were both correct, thanks for your suggestions, which gave my the courage to try connecting the ground lug, even though I didn't think that it was necessary!

Originally Posted by TG Twinkie

The earth ground connection has nothing to do with the converter output.
I see the wire which is connected to the fuse on the wall. Where does each end of it connect? Typically the fuse is inline with the negative battery lead. I see it loops up but can't see if it is connected to anything other than the fuse on the wall.

And thank you for you input! I've really enjoyed reading your posts about your Argosy restoration over the passed few years.

Even though you were wrong in *this* specific instance, with *this* very specific model of power converter, what you are saying actually matches the advice that I got from PowerMax themselves ...

From: Graham - PowerMax Converters <graham@powermaxconverters.com>
Date: Thu, 25 Aug 2016 10:50:28 -0400
Subject: Re: PM4 Wiring Question ... not currently working.

John,

It's best to connection the + and - outputs on the PM4 to the + and -
battery posts and then onto the fuse block. This way when the AC power is
off you will still get DC power from your battery.

If you have grounding in the AC side which the PowerMax is plugged into you
don't need to ground it. If not there is a small grounding post on the back
if unit in middle.

Hope this helps

Graham

[elmer]

One final reading from today, and then I think that this tread is probably done.

Fuse-panel DC reading with PM4 connected to shore power overnight ... 12.9V all house lights off, 15W AC draw as registered by the Kill-A-Watt.

[68 Overlander]

TG Twinkie is mostly correct and Graham is definitely incorrect as far as most OEM's wire their DC (Including Airstream) Its best to connect the + and - to the fuse board first, then on to the batteries. That way if your battery dies, or needs removed for any reason, you still have a 12 volt power supply from the converter. If shore power is off, your battery will still feed the fuse board. Your wiring is not as Graham said and that's okay, actually better from the glance I saw. You/he are describing the way an inverter/charger is wired in that the batteries must be part of the system. Without them (battery) you break the 12 volt connection. BTW, I know Graham well and he has good intentions as do we all

[elmer]

Originally Posted by 68 Overlander

TG Twinkie is mostly correct and Graham is definitely incorrect as far as most OEM's wire their DC (Including Airstream) Its best to connect the + and - to the fuse board first, then on to the batteries. That way if your battery dies, or needs removed for any reason, you still have a 12 volt power supply from the converter. If shore power is off, your battery will still feed the fuse board. Your wiring is not as Graham said and that's okay, actually better from the glance I saw.

What you're saying is what made the most sense to me when I hooked things up, and so that's what I did, and it's what you're seeing in the photos.

It just made sense that that's *why* there are all those connection lugs on -ve and +ve buses on the FB9 fuse panel.

If things still hadn't worked after I tried the ground wire, then I'd have been forced to try to *exactly* match the circuit layout that's on your web page, and that Graham described.

My confusion was with both TG Twinkie and Graham both *seeming* to suggest that I should not need to connect the PM4's front ground lug to anything (since the PM4 is grounded through the AC connection when it is plugged in).

For whatever electrical reason, that doesn't actually seem to be the correct advice with this particular converter in my particular Argosy.

Originally Posted by 68 Overlander

BTW, I know Graham well and he has good intentions as do we all

I really appreciate everyone's help and advice here, and your responses to someone that didn't buy their converter from you, and Graham's attempt to help when he could (and perhaps should) have just told me to get in touch with the Amazon reseller.

I've already sent my thanks to Graham.

[68 Overlander]

Originally Posted by elmer

I really appreciate everyone's help and advice here, and your responses to someone that didn't buy their converter from you, and Graham's attempt to help when he could (and perhaps should) have just told me to get in touch with the Amazon reseller.

I've already sent my thanks to Graham.

You'd be surprised how deep we'll get with people who are nice..You weren't so much at first and kinda had things figured out on your own until you didn't and had to reach out.
And that green wire should actually go to chassis but you'd be surprised now many don't connect it to anything and it still works. Nothing to do with Argosy.