Inverter/Power Issue

[johnpostava]

2016 Airstream Sprinter Grand Tour. Generator is on running down the highway, inverter on. We start a DVD in the player and within 5 minutes power cuts out to TV and player then comes back (1-3 seconds). Movie restarts (from beginning kids are ). Happens again every 15 or so minutes after first drop (kids REALLY unhappy). Dealer is working with Airstream. They think it is something to do with inverter. Airstream had dealer tweak the inverter. Dealer reports unit still drops after first 5 minutes but no additional dropping after first one (better but not acceptable for a 100K-plus RV). Dealer states they are still working with Airstream. Unit has plenty of available power. Any thoughts I can relay to the dealer?

[73shark]

Does it drop out if inverter is Off?

[Mcrid]

With generator running, the internal bypass switch should be running the outlets off the generator and not the Inverters output. Turn the generator off and see how it operates just off the batteries. If all is OK, then check the inverter settings (dropout voltage, Search watts, etc.) to see if something is set strange. If all OK there I would question the Magnum's internal transfer switch as being faulty.

[Protagonist]

I'm inclined to believe the problem originates with the generator. When you're on generator power, the inverter/charger is not inverting— it's charging— and your 120vAC power is coming directly from the generator.

My best guess for the cause is slightly low oil in the generator, not low enough to cause the low-oil cutout to cut out completely, but low enough that a bump can cause the oil to slosh enough that it momentarily uncovers the sensor and fools it into thinking the oil is low. Then the oil sloshes back and the generator doesn't do any more than hiccup. But that hiccup still causes a momentary interruption of power.

For the sake of your kids' happiness, turn off the generator and run the television/DVD from the inverter only, unless the temperature is hot enough that you have to run the rooftop A/C while driving.

[lewster]

Good suggestions so far.

The problem is to isolate the 'burn' in the 120VAC output that the TV circuit is receiving.

Since it is running thru the inverter's 'pass-thru' circuit, that may be an issue. It would be the AC section of the board that controls this relay and the pass-thru to the outlets when shore power is present (that included generator also). I have my suspicions about this, since the inverter is also charging the batteries when 120VAC power is present and the charge light should be on at the panel. The inverter WILL NOT INVERT if 120VAC power is present even if the inverter button is activated, but will pass the power thru to the circuits connected to it's 120VAC output.

Since the Magnum does not distinguish between actual plug-in power or generator power, plug the coach in and try the same set of circumstances again. If you get the same interruption, it's the inverter. If you get NO PROBLEMS when plugged in, I would go with Protag's solution of a generator issue.

Either way, it would be good to verify the settings on the magnum ME-MR control panel first.

[Mcrid]

Lewster and Protag are the experts in this area. I'm a Newbie. That said, as an EE, there is one thing that annoys me when we talk about the Magnum. There are Rectifiers and there are Inverters. They are not the same thing. The Magnum is a Rectifier AND Inverter with an AC Transfer switch. The Rectifier takes AC power, converts it to DC to charge the batteries. It is a separate internal circuit. https://en.wikipedia.org/wiki/Rectifier. Then from the DC bus (connection) takes DC and "Inverts" it to AC. The circuits are separate.

So for trouble shooting keep this in mind. Are the batteries being charged? Yes/No. Is the Magnum producing AC yes/No. Is AC passing through the AC switch? Yes/No. Answering these questions can help isolate the area of the problem. Then as Lewster suggests, look at the settings of the Magnum and make sure they are correct as they could be asking the Magnum to do things that is causing the problem.

I know very little about the ONAN Genset so I'd follow Protag's advice on checking this to confirm or rule it out. But if the Magnum works flawlessly on the batteries then that is a very good clue. Also, you have a 220 amp alternator that is charging the batteries down the road so why run the Genset unless it is so hot you need the House AC.

Good luck and let me know what you find out as I have a '16 as well