Charge Surging - Xantrex 458 / Onan 7.5

Dmreese1 · 02-18-2011, 06:42 PM

Guys,

I had an interesting experience this week that I would love to get constructive comments on from the knowledge base here on the forum.

We are in Key West at the NAS RV Park at Sigsbee which is mostly dry camping. Batteries saw heavy use and I was running the Onan Genset at about 75 amps charge load. I noticed a surging issue with the charge current dropping to zero and than back up to 70-75 amps after a few minutes. Later in the day the charge current went to zero and stayed there.

Checked the generator out put and it was 122 Vac at the transfer switch and connected to the inverter. Had no charge or pass thu AC voltage. Checked and cleaned all the battery connections and then dug into the AC input / output and had AC in but not out. Checked all the breakers and found the inside 15 amp Inverter breaker red, so I reset it. Bingo, full charge and AC was OK.

About an hour into the charge I had the same surging so I shut down the generator and turned it back on and had full charge current until the charge was complete over about 3 hours.

Didn't get a chance to check if the generator Ac at the transfer switch was at 120 Vac when the charge was surged off but if it does it again I will be sure to isolate whether it is the generator or at the inverter.

Any thoughts or suggestions?

Duane

The General · 02-21-2011, 04:00 PM

Duane,

How old is Gene?
Is maintenance up to date?

I like to go to the basics so:
Check altitude adjuster for proper altitude.
Check gene oil and top off.
Check fuel level in tank; should 1/4 or higher.
Lube governor pivot points.
Flip breaker switches off and on while Gene's not running.

Steve Bernard
President Gold Country Roos of Nor. Cal.
2008 Fleetwood Bounder 35E/ Ford F53, Triton V-10, 30 valve, 364 HP
2007 Saturn Vue Redline

Dmreese1 · 02-22-2011, 10:10 AM

Hey Steve,

Thanks for the thoughts and advice. On follow up, I kept after this and pulled the inverter out and checked all the connections. What I found was a breaker to the inverter that had partially tripped. Apparently it was making partial contact and was not conducting well under heavy load. I tightened all the connections at the breaker and the inverter and reinstalled everything and the issue has not repeated.

Fot the past 3 days we have been charginh to full every other day and watching the current draw carefully. I have a 135 watt solar panel on the roof that gets a full sun during the AM thru the early afternoon before being shadowed by a tree. We are finding that we can conserve well during the day and run the inverter for TV and the generator for cooking with the microwave, etc. The solar panel covers all the phantom loads, lets us invert to have a fan running and still puts about 3 amps into the battery bank.

I run the genset for about two hours every other day to charge at 80 amps / secondary 25-30 amps stage and then cut it off when it falls to stage 3 charge of about 6 amps. At the end o f two days, we see about 70% remaining in the batteries and thats when I run the genset.

Duane

The General · 02-22-2011, 10:22 AM

Duane,

It pays to check out the complete charging and associated systems to make sure all wiring is connected and tight, breakers are free of corrosion, and areas to be lubed are maintained.
Great to hear you resolved your problem.

Steve

Dmreese1 · 03-02-2011, 06:07 PM

Quick update on the surging issue. After checking connections up and down stream form the inverter, I found no connection issues. I ended up pulling the Xantrex Freedom 458 out of the coach per Xantrex' advice and cleaned and tightened all internal connections.

When I re-installed the unit, I had NO charge at all.

Started looking at things and found that I had a 1.5-2 volt drop across the 300 Amp Buss Fuse from the Inverter to Coach batteries. Jumped around the fuse and bingo, charging restored. Replaced the fuse today and things are back to normal.

Duane