-
inverter puzzle
A couple of months ago, wife got up during the night to use toilet. We were doing an overnight boondock and as we usually do in that situation, had run gen until we went to bed and let batteries take over then until morning. Nothing except lights/refrig/etc on during the night. We have Headhunter Mach 5 water pump and Headhunter royal flush toilet. Both had been working fine but when she flushed got nothing. I went out and pump looked ok but not running so had her try it again and low and behold, voltage on techlink screen for inverters (which I always leave on during the night) showed drop in voltage on inverter #2 (which the pump is on) to about 80 volts. Started gen, voltages both showed 120 and then toilet worked fine.
After that did some repeats with same result and on occasion pump went into reset presumably because of low voltage being applied. Also, after this problem started, noted that the resting voltage on #2 was a little low on the techlink screen. Normally in the past when on inverters, both had run right at 120. Now #2 hanging at 110 or a little less. BTW: Things seem to work fine and voltages measured at the inverters are normal on shore power with normal battery charging with no drops with loads applied – and same with gen being used.
Started looking into things after we got home and noted the now low voltage on the techlink screen for #2 was not what was at the inverter output lugs – which was 120. What? More fussing around and found output measured at the lugs on #2 would drop when I had wife flush toilet. Took output from #2 to the bus out of the picture and rigged up feed to a couple of heaters to supply load. Same deal. Load (10 to 12 amps) gave big voltage drop. Measured incoming DC voltage at around 26 with only a few hundredths drop with load application – same as with the toilet flushes (which draws about 10 amps). Hmmm. Discussed with tech support at Marathon and conclusion was new inverter needed. Mine are Trace SW 4024 and no longer made, of course, but finally found a rebuild from a guy that does rebuilds for Marathon. Big bucks, of course. He doesn’t take questions.
Installed rebuild and same thing with pump now nonfunctional. Hmmms only. Great. Should have stopped hook up into coach when I first had trouble and began testing. So adding to my happiness is need for new water pump and I am hoping to find something other than the hideously expensive Mach 5 that can operate the royal flush toilet which takes some big time pressure and flow. On back page for now.
So now tech support at Marathon says the rebuild is bad. Yikes. Two bad inverters? What are the chances of that? The guys at Marathon are still answering my calls BUT everybody (especially me) is out of suggestions. I am open (make that desperate) for suggestions from the busosphere. Sorry for the long post. If you know the answer, I’ll put in a good word with Santa for you.
Mike
-
9 Replies
-
Can’t help with the inverter issue but, Headhunter sells factory rebuilt pumps for half the price and warranties them. I have installed a few on boats I have worked on with no issues.
Many of the pumps haven’t even been used. People purchase them with out checking the voltage requirements, receiving the pump and realizing it’s AC voltage not DC, then return it unused.
Chuck
-
Harbor Freight
and others is what I have planned if/when my expensive 12v Groco calls it quits.
My LIberty has a Headhunter, works perfectly with pump cutoff max pressure of 37 psi and restart at 30 psi, but it does have a 4.5 gal diaphragm surge tank.
-
Chuck:
I asked about that. Told they don’t do that anymore. Mike
-
Have you checked your batteries Billy? Do you have the same issue when plugged in to shore and on inverter pass through? The guys at Inverter Services are great for helping diagnose problems.
-
Don:
That looks like it should work and the price is stunning. I could put in one of those per year for over 10 years for what a Mach 5 costs. Looks like worth a try to me. We are just trying to flush a toilet here not supply a cruise ship and most of us know how to install a pump. Thx. Mike
-
Tom:
Do not have the same problem on shore power or on bypass. Or on gen. Toyed with the idea of taking all the house batteries out and load testing each one but in discussion with Marathon tech decided not to since the 24VDC feed stays good with load application. Inverter Services certainly has a good reputation so I did call them. Didn’t seem anxious to discuss anything over the phone. Said come on in and we will look at it. Close to doing that even though they are nearly 1000 miles away. Thx. Mike
-
while a long shot, Mike, low inverter output could be caused by loose or faulty ground cables resulting in low voltage at the dc connectors. Pull the cables off of the inverter connections and measure voltage at the cable ends. Reinstall them and measure at the inverter connectors to see if there is any difference.
Jerry
-
Sounds like you have a bad battery(ies), corroded connection, bad cable. Check those first.
-
Jerry and Mikee: Did all that. Plot thickens with second inverter. Turns out it was dropped during shipping. Was packaged in wooden box and on pallet according to seller but arrived to me in a flimsy cardboard box (and no pallet) which itself was pretty beat up. Thought something was fishy when it made all sorts of nonelectrical noise (sounded like a food processor chopping whole walnuts) when I started it up and then never worked right even when I set up a test station on my workbench entirely separate from the bus. So now it is on its way back to seller and plan for now is to run entire bus off one inverter. We seldom pull much inverter power – about 10 amps with a toilet flush during a rare boondock night at most – so should be plenty of power to get us by for now and each inverter charges the entire battery bank so charging should be good. Plan to hit Inverter Services on our way to FL this winter and see what they say. Hopefully I will be able to get a refund on the 2k I paid for the rebuild.
Don: As usual your thoughts are great. Now have a nicely functioning Harbor Freight pump installed and works like a charm flushing the Headhunter royal flush toilet without problem. Total cost with discount and taxes: $162. Long way from the nearly 2k for a new Mach 5.
Appreciate everybody’s input. Mike
Log in to reply.