Xantrex inverter issue

The friendliest place on the web for anyone with an RV or an interest in RVing!
If you have answers, please help by responding to the unanswered posts.

Ronnerickson

New member
Joined
Oct 25, 2017
Posts
4
I recently installed a Xantrex Freedom Xi 2000 watt inverter.  The inverter works fine
When converting 12v dc to 120 ac.  The problem I am having  is related to the internal transfer relay.
When I am connected to Shore power (plugged in at home) the inverter automatically stops inverting and
Passes through shore power.  On the remote display the light switches from yellow to solid green
To show that it?s using shore power.  When i unplug shore power the inverter automatically switches back and starts inverting.      But, if I start my generator (onan 4000) for shore power the inverter keeps inverting and acts like it does not see the 120v and will never switch to shore power.  The light stays yellow and will never switch to green.  I have verified there is 120v AC on the input when the generator is running.  So i don?t understand why it works perfectly using AC from power grid but does not work when using generator.  Here is the kicker, if I turn my air conditioner on then all of a sudden the inverter will switch to shore power.  But I verified with a multimeter that the voltage is stable at 120v.    Any ideas?
 
Ronnerickson said:
I recently installed a Xantrex Freedom Xi 2000 watt inverter.  The inverter works fine
When converting 12v dc to 120 ac.  The problem I am having  is related to the internal transfer relay.
When I am connected to Shore power (plugged in at home) the inverter automatically stops inverting and
Passes through shore power.  On the remote display the light switches from yellow to solid green
To show that it?s using shore power.  When i unplug shore power the inverter automatically switches back and starts inverting.      But, if I start my generator (onan 4000) for shore power the inverter keeps inverting and acts like it does not see the 120v and will never switch to shore power.  The light stays yellow and will never switch to green.  I have verified there is 120v AC on the input when the generator is running.  So i don?t understand why it works perfectly using AC from power grid but does not work when using generator.  Here is the kicker, if I turn my air conditioner on then all of a sudden the inverter will switch to shore power.  But I verified with a multimeter that the voltage is stable at 120v.    Any ideas?

Welcome to the forum.
If nobody here gives you advice, I would make a call to the company. You said you recently installed it so it may be covered by a warrantee.
 
I haven't owned a pass through but it might make me wonder about bonding. The shore is bonded but generators often are not. Could it be that the generator isn't bonded and the inverter is seeing that? I haven't owned a 4000 Onan so dont know if they bond but just thought I'd mention it. I have run into rigs that are wrongly bonded, Magnum auto bond pass through inverter with wrong permanent bond in the sub panel.
 
Usually the problem is the generator power isn't stable enough to be recognized as valid AC power by the inverter, so it refuses to pass it through.

Voltage usually isn't an issue since the Xantrex will accept 100-130 volts as valid power, though it's possible your generator could be near the top of that range without a load.  Unless you have a true RMS reading voltmeter it may not accurately measure the generator's voltage.

The frequency stability of the generator may be a problem.  Very few generators short of large, industrial standby power systems stay at a true 60.0 Hz frequency throughout the entire operating range.  The Xantrex checks for 20 seconds of "stable power" but there's no mention of what it considers stable.

The fact that the inverter transfers when you turn on the air conditioner and put the generator under a load suggests the generator is running slightly fast when it's not loaded.  An easy way to measure the generator's speed is to get a Kill-A-Watt plug in power monitor, plug it into a generator powered outlet and select the Frequency function.

Same thing for monitoring the voltage.  You don't need it to be in line for these two functions, just plugged into an outlet.

The Kill-A-Watt is about $20 at Amazon or at many hardware stores.

If this doesn't help, I'd call the factory and see what they have to say.  I'm sure you aren't the first person to install this in an RV.
 
I think Lou is right on target - the genset output is probably slightly off-spec (compared to utility power) with no load on it, probably in both voltage and frequency.  You might even find that a very light load, 60 watts or so, is enough to steady it up. Try plugging something else into a non-inverter outlet (turned on, of course) and see if that also gets the inverter's attention. Or put the fridge or water heater in electric mode to generate a load (those are bigger loads, though).  If that works, it verifies the nature of the problem and maybe we (or Xantrex) can brainstorm a reasonable solution for it.
 
Thanks for the input guys.  So Xantrex verified exactly what I was seeing.  They said the inverter AC input checks the quality of the sine wave, frequency and voltage.  (manual just says voltage).  She said at idle or with no load the parameters are not within spec so the inverter wont transfer to shore power.  But when there is a load on the generator (ie with the Air conditioner on) then the signal is "cleaned up" and the inverter will switch to shore power.  She described exactly what I am seeing.

So, here is the question.... Is there anything I can do about this?  I am thinking no.    I live in Arizona, so a lot of the months the air conditioner is running and their wont be an issue.  But this past weekend I went camping and temps were 36-61 up north, so no Air conditioner needed.  When running the generator the TV does not put enough load on the generator to clean up the signal.  So the inverter switches back and forth between shore (generator) power and inverter power.  The annoying aspect is when it switches during the brief moment it turns off my TV that I am watching. (or whatever AC component I am using) I know I know, first world problems.  But I like when things work seamlessly. 

The only thing I can think of as a solution would be to have a manual AC selector switch between incoming AC and the inverter, and manually turn the inverter on and off when I want inverter power.  Bummer I have to do this because it would be nice if it would work automatically.
 
I guess a small UPS for the TV could solve the delay when it switches between shore power and inverter.  It only needs to last a couple seconds of switching time.  Thoughts?
 
Did they tell you what its parameter ranges were? 

If you figure out how much load is needed to get the genset smoothed out, maybe we could come up with something. If it takes kilowatt load, you probably won't want to wire in a steady dummy load that big. If only 100 watts or so, then maybe.

You should also investigate the genset itself - it may be possible to bring it closer to what the inverter expects.  Your particular one may simply be a bit further out than most. My Onan QD 7500 always stayed close enough to standard power that inverter and such were always happy. Get the Kill-O-Watt device Lou suggested and measure frequency and voltage so you know what you are dealing with.

Yes, a UPS on the tv would handle that aggravation.
 
I think I will go ahead and buy that kill-o-watt and see what I find.  I will report back when I have it.    They did not tell me what the parameters were for the sine wave and frequency. 
 
Where as I do not know that model I do knwo the PRosine manual

THe Prosine monitors not only Voltage, but frequency and waveform.

Your generator may be running fast, or slow, or dirty
Most ONAN and GENRAC RV type generators are clean power.. but they can run fast or slow.

Most "Contractor" generators (portables) are not so clean and the inverter may decide to PROTECT against the spikes and noise (electronic)  they generate.
 

Members online

Forum statistics

Threads
131,753
Posts
1,384,359
Members
137,524
Latest member
freetoroam
Back
Top Bottom