New Converter Question

You are saying that the converter reaches proper voltage when running off the generator but not shore power?

Ok, that is , in a word, ODD since generator power and shore power are a lot alike (Unless of course the generator is charging the batteries itself, most RV only the main engine (Motor homes only) and the converter can charge the batteries, the gen-set does not have that ability, it relies on the converter,  HOwever I'm sure (in fact I know) there are exceptions)

Now... If that is the case check for 120vac to the converter when on shore power.. If your unit is a plug in,  just un plug it and plug in the largest lamp or floodlight you have on hand (in my case I think that is 150 or 300 watts, w/o looking I'm not sure, have not used it in some time) 

If your unit is a plug in,  just un plug it and plug in the largest lamp or floodlight you have on hand (in my case I think that is 150 or 300 watts, w/o looking I'm not sure, have not used it in some time) 

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OK, unplug the converter and plug in the biggest lamp I have on hand...................what is that going to do for me? 

I did plug a 60 watt lamp into that same outlet before I measured the outlet voltage and it worked fine.  I then tested that outlet with a digital voltmeter and it was right on 120V.   So what have I learned from that?

You learned that shore power is supplying good voltage to the converter. When things are acting really strange like this, you have to verify EVERYTHING rather than ASSUME.

The converter will shortchange the battery charging is there is a lot of 12v power demand from the house 12v circuits. Just to make sure you are comparing apples to apples, make sure all other 12v loads are the same (preferably off) when comparing voltages on generator vs shore power.

OK, so it appears that either the generator is charging the batteries directly (which would be highly irregular) or else there is some 12V demand when on shore power that is absent or diminished when on generator power.  I don't believe any additional 12V devices were intentionally turned on or off between testing the shore power supplied voltage and the generator supplied voltage measured on the output side of the converter. 

However, one unusual thing I did notice was that when I was measuring the voltage on the output side of the converter when the generator was running, the voltage was steadily increasing.  I don't remember where it was when I started measuring it but when I watched it going up past 13V and then past 14V I continued to watch it as I thought it would stop at 14.4V which is the charging rate the Charge Wizard outputs when in Boost Mode.  But no, it went even higher than that.  I don't know how high it got, as I quit measuring when it got a couple tenths of a volt higher than 14.4V because my theory didn't hold up and it was moving up much slower at that point.  I guess I was too busy scratching my head to notice the peak charging voltage that it eventually got to.  ??? ??? ???

Another unusual thing I noticed (but corrected) was that the Charge Wizard dongle(?) was attached (glued) to the top of the PDI 9155 converter box.  I remember reading somewhere that you aren't supposed to do that so we removed it away from the converter box, but with no resulting changes in the observed charge rate.

Rolf, is it possible that on this so called "modernized" RV that the original converter still exists somewhere in the motorhome (still hooked up to the generator) and that the 9155 is not working at all on shore power or generator?

Did you run the generator to see if there is DC developed with the 9155 completely unplugged?

Rolf, is it possible that on this so called "modernized" RV that the original converter still exists somewhere in the motorhome (still hooked up to the generator) and that the 9155 is not working at all on shore power or generator?

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Lou, it wouldn't surprise me.  It also wouldn't surprise me if this converter is hooked up only to the chassis batteries either!  How's that for a shocker?  No, the reason I believe it's hooked up to the coach battery is because I measured the voltage at the coach battery and it was the same as the voltage at the output of the converter.  I haven't traced the battery cables because I had no reason to doubt that they led to the coach battery from the converter.  But the position of the converter (under the bed in back) tells me that this probably isn't where the original converter was positioned.  In fact, the owner didn't know where the converter was and we searched all over for it before finding it under the bed.  There's a breaker box there also and a transfer switch. 

Kind of unusual but everything about this coach has been redone.  It's got all new furnishings inside, new carpeting, new factory paint job outside, new tile floor, etc.  For a coach with no slides, this thing is really pretty nice.  The owner just got it delivered (he hasn't even driven it yet).  And the previous owner doesn't know anything about it.  He's in contact with the 2nd previous owner who does know more about the history of the coach, so he can get some reliable information when and if he needs to.  (I would be all over that guy to find out exactly what he's got here!)  Larry, the current owner, is a friend of a friend, so that's how I got involved. 

Did you run the generator to see if there is DC developed with the 9155 completely unplugged?

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When Larry ran the diesel generator, there was over 14V on the output of the converter.  He started the generator while still hooked to shore power (something I never do) and we could hear the transfer switch doing its thing after a  few seconds.  But how could I tell if DC was developed with the 9155 unplugged?  Wouldn't all the 12V circuits still run off the coach battery whether the coach battery is being charged or not?

But how could I tell if DC was developed with the 9155 unplugged?  Wouldn't all the 12V circuits still run off the coach battery whether the coach battery is being charged or not?

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Unplugging the 9155 would show if there is another source that is charging the batteries. If the battery voltage still goes above 12.6 with the 9155 unplugged, then something else is charging when the generator runs.  That would mean either that the 9155 is not working or that the other voltage source has somehow fooled it into going idle.  By the way, that's part of the reason for testing the 9155 output with the batteries disconnected from it. When things are bizarre like this, it is best to isolate components to test them, to eliminate any possible interactions, no mater how unlikely they may be. Something is not performing to standard specs and we need to figure out what it is.

The 9155 cannot tell shore power from generator, so that should not be a factor UNLESS either shore or generator is putting out non-standard 120vac power (either incorrect voltage or incorrect frequency). Presumably the shore power is ok if it feeds other things and they work, but the generator could be off in voltage or frequency or both.

==When Larry ran the diesel generator, there was over 14V on the output of the converter.  He started the generator while still hooked to shore power (something I never do) and we could hear the transfer switch doing its thing after a  few seconds.  But how could I tell if DC was developed with the 9155 unplugged?  Wouldn't all the 12V circuits still run off the coach battery whether the coach battery is being charged or not?==

YES. the 12 volt systems will still run off batttry.. IF the battery is connected

However. they will be running at 12.x volts

Try this, since you say the voltage rises with GENERATOR operation Start the generator, observe rising voltage, UNPLUG the PD converter and observe voltage.. If it continues to rise you have a second source of charging voltage on the system Either the generator itself or a 2nd converter

If it then falls.. The PD is working

You do need to verify shore power is getting to the PD

rsalhus said:

When Larry ran the diesel generator, there was over 14V on the output of the converter.

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Rolf, I guess I wasn't clear on my objective of unplugging the 9155 and checking for developed voltage (meaning the 14.4v) that you see when running the generator.  The idea was that it COULD NOT be coming from the 9155 converter if it's input (120vac) is unplugged.  Gary suggested unhooking and isolating the output side earlier I just thought you might consider this an easier choice for isolating the converter.

rsalhus said:

But how could I tell if DC was developed with the 9155 unplugged?  Wouldn't all the 12V circuits still run off the coach battery whether the coach battery is being charged or not?

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I think the 14.4 you are reading at the converter output is actually being developed by another source.  That's why the isolation of either the input or output of the converter.

Sorry my previous remarks were not clear.  I didn't want them to sound too blunt or condescending.

Hey, guys, thanks for all the help.  I'm hoping to get back over there today sometime and try a few of your suggestions.  Maybe I'll even take a few pictures if Larry doesn't mind.  I'll let you know here how it goes.

Don't forget to check the fuses on that thing too

rsalhus said:

But with both battery cables connected and with the Charge Wizard connected and it's light on solid, the output voltage from the converter was only 12.5V.

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I called Progressive Dynamics tech support, when my 9160 was acting up and I wanted to troubleshoot before declaring it dead.  That guy told me that it should measure at least 13 volts at the output.  At the time mine was measuring about 3v, so there was an obvious difference.  With yours (or your friend's) at 12.5v, I don't know but it's still less than 13. 

If you figure out there is NOT another charging source, I'd give Progressive Dynamics a call and explain everything you've tested.  I don't have the number handy but I know it's on their website.  They were pretty helpful when I called.

OK, just got back from Larry's place.  We ran the generator (without shore power connected this time) and we saw 14V plus on the output side of the 9155 converter.  When I pulled the 120V cord powering the converter, we still saw 14V plus on the output side of the converter while the generator was running.  So we concluded that the generator was charging the coach battery somehow.  Larry claims that there is only one converter in the motorhome that he knows of.  We looked around but didn't find another one.  Larry said the 2nd previous owner told him that the PDI 9155 converter has been replaced at least once before when he had trouble.  Is there any chance that this charging voltage coming from either the generator or another converter could harm the 9155 converter?  Larry wants to buy a new converter (he probably should get the 9260 model?) to replace the 9155 but I'm wondering if maybe he should unplug the converter whenever he runs the generator, what do you guys think?

If you figure out there is NOT another charging source, I'd give Progressive Dynamics a call and explain everything you've tested.  I don't have the number handy but I know it's on their website.  They were pretty helpful when I called.

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Scotty, I gave Larry the telephone number of the guy at BestConverter.com, Randy I think his name is, and he called him.  I think they seemed to agree that since Larry doesn't see 13V plus on the output side of the 9155 converter when connected to good shore power, that it must be bad.  But this is probably the 2nd or 3rd converter they've gone through in this motorhome so something must be wrong with the setup.

Bingo!

I think he (with your help) should find out where that 14.4 volts is coming from. 
Perhaps if you would post all the data you can determine from his generator make and model, we can get some ideas.

IF he can't find the mystery source, then I agree with you.  Why make chargers/converters butt heads.  If one isn't damaged, it will at the least, be confused.

Good work, Rolf...

PS - just for grins, the next time you have a look at this RV, check to see if there are any 12volt fuses or circuit breakers on/near the generator.  I have never seen a chassis mounted generator with 12v charge capability, but that doesn't say they don't exist....

rsalhus said:

Scotty, I gave Larry the telephone number of the guy at BestConverter.com, Randy I think his name is, and he called him.  I think they seemed to agree that since Larry doesn't see 13V plus on the output side of the 9155 converter when connected to good shore power, that it must be bad.

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The bestconverter.com people probably know their stuff, but you may want to have Larry call Progressive Dynamics direct since they manufactured the unit.  Here's their service info from their website:

PROGRESSIVE DYNAMICS SERVICE DEPARTMENT
507 Industrial Road
Marshall, MI 49068
Telephone ? 269-781-4241
Fax ? 269-781-7802
E-mail ? [email protected]

rsalhus said:

But this is probably the 2nd or 3rd converter they've gone through in this motorhome so something must be wrong with the setup.

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Sound like a good possibility.  If the converter OUTPUT is somehow receiving 14 volts when UNPLUGGED, I'd say something is connected backwards in the wiring somewhere!  What you're reading is actually the INPUT from another source.  I don't know what else that could be except another converter.  The 9155 should have fuses to protect against damage caused by backwards current though.  As far as replacement if it comes to that, the 9200 series simply has the charge wizard built-in.  It's an optional add-on with the 9100 series.  Otherwise they are identical I believe.

PS - just for grins, the next time you have a look at this RV, check to see if there are any 12volt fuses or circuit breakers on/near the generator.  I have never seen a chassis mounted generator with 12v charge capability, but that doesn't say they don't exist....

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Lou, I'll do that.  I'm a little out of my league here..... don't know if there's anything else I can help him with.  I crawled under the motorhome trying to trace the cables from the battery tray, but no luck there.  I'm going to take some pictures later, this motorhome is really different from others I've seen.  I think you guys would get a kick out of seeing a '93 motorhome that looks like new, I know I sure do.

The bestconverter.com people probably know their stuff, but you may want to have Larry call Progressive Dynamics direct since they manufactured the unit.

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Thanks Scotty, I'll pass that on to him.

It's time to disconnect the battery feeds at the 9155 end and check the output right at the inverter. That way you will know definitively whether it is working or not.  It sounds like it is not, since there is no output when the generator is off, but Larry ought to be sure before buying a new one.

I would not install another converter until you find out what is destroying the converters and where that 14+ volts is coming from. The fact that it is a rising voltage is worrisome - could even be AC rather than DC  Your meter will give invalid results if you have it in DC mode and use it on an AC source.

RV Roamer said:

It's time to disconnect the battery feeds at the 9155 end and check the output right at the inverter. That way you will know definitively whether it is working or not.  It sounds like it is not, since there is no output when the generator is off, but Larry ought to be sure before buying a new one.

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I agree.  Especially since he has to disconnect them anyway to replace the unit....

RV Roamer said:

I would not install another converter until you find out what is destroying the converters and where that 14+ volts is coming from. The fact that it is a rising voltage is worrisome - could even be AC rather than DC  Your meter will give invalid results if you have it in DC mode and use it on an AC source.

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I guess it could be an AC voltage superimposed on the 12.5 VDC battery voltage.  Probably a real stretch, but anything is possible.  My guess is a highly unregulated DC output from the generator or something attached to it.  Interesting phenomenon to say the least.

OK guys, first let me show you some pictures of Larry's motorhome.  It's a '93 Gulf Stream Friendship 38 footer.  It's got a Cummins 300 HP engine.  It's been repainted so it looks much newer than it is.  Picture one shows that.  Picture 2 shows the generator, an Onan 7.5K diesel.  Picture 3 has some specifics of the generator.  And Picture 4 shows the PDI 9155 charger.  I don't see any circuit breakers in the generator compartment for a converter.

OK, so where do we look to find the mysterious converter?  I haven't a clue.  ??? ??? ???