Led lights flicker when using the generator

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sluggermike

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I replaced most of my interior lights in my class A motor home with led lights.  When using shore power the lights work fine, but when dry camping using my Onan 5k generator they flicker constantly.  The old lights don't flicker.  I don't understand why they flicker because they are 12vdc lights and run off the house batteries.  I'm wondering if there is something wrong with my electrical system, or maybe the leds are too sensitive?
 
sluggermike said:
I replaced most of my interior lights in my class A motor home with led lights.  When using shore power the lights work fine, but when dry camping using my Onan 5k generator they flicker constantly.  The old lights don't flicker.  I don't understand why they flicker because they are 12vdc lights and run off the house batteries.  I'm wondering if there is something wrong with my electrical system, or maybe the leds are too sensitive?
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It is time to find someone with an oscilloscope to monitor the AC and DC lines.  They should be looking for voltage and/or frequency variations in the AC line, voltage variations on the DC line as well as some AC on the DC line.  Hope this helps.
 
Our rig came with led's, the only time they flicker is if the batteries are low right after the gen is started and before the gen electrical kicks in. Once the gen electric kicks in the flicker stops. Its the gen fuel pump causing the flicker. I wonder if your gen electrical isn't  properly kicking in. Ours is a 2015 C class, not sure how similar the electrical systems are. Do they flicker with the gen on while driving?
 
Leds are sensitive to both voltage and power quality (the AC content that Jim referenced).  The old incandescent bulbs were not and in fact smoothed out such things. And some inexpensive Leds are more sensitive than others, simply because the cheapest ones lack adequate power regulation (and led bulb actually has a tiny circuit board in it).

When the genset is running, the RV 12v comes from the converter/charger and that too is often sensitive to voltage and , so yes you could have a problem there as well. If the incoming AC voltage is low or fluttering, the converter will probably put out a lower or variable DC voltage. Off-frequency (not 60 Hz) can also cause this.  What make & model converter/charger (or inverter/converter/charger) does you rig have?

Is there any flickering when on battery alone (no genset or shore power)?
 
What about putting sometime like a 40mf capacitor in the supply line to filter out the pulsating DC or trace AC  ?
 
I have a 2004 Fleetwood Terra with two 6 volt house batteries.  The batteries are seven years old, but are still working well. When I use shore power, the led lights are constant, no flickering.  It is my understanding that the generator provides AC power to the converter that is then converted to 12dc that recharges the batteries which supply 12vdc to the lights.  The 12vdc I would think would be separate from the power the generator provides; and therefore, It would not cause the flickering.  I'm wondering if there is some type of cross over in the converter.
 
Gary's comments are appropriate.  The inverter is critical and may allow an AC component to come through or the converter may be relying on the batteries to adequately smooth the DC either way if there is not enough filtering, the flutter is there.  Adding a filter network, i.e., capacitors and inductors, like we used to do in the old cars will help the problem but it will only cover up the problem, not resolve it.
 
It is my understanding that the generator provides AC power to the converter that is then converted to 12dc that recharges the batteries which supply 12vdc to the lights.
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That's not quite how it works. The converter/charger operates in parallel with the storage batteries and directly supplies 12v power when active. In essence, it serves as an additional electronic "battery". Because the storage battery voltage is lower that that provided by the converter/charger, for practical purposes the storage battery becomes inactive whenever the converter has 120v power. In most situations the storage battery is actually being charged while the converter is also supplying 12v power to the rest of the RV.

 
Thanks for the explanation on how the converter/charger works.  It sounds to me like the converter/charger maybe the problem?
 
It would appear that the generator is the culprit.  If the lights are noticeably flickering it has to be at a relatively low frequency, likely a submultiple of 60 Hz like 15 Hz.

Ernie
 
There is no flicker when using shore power which according to Gary means my converter/charger is ok.  I am at a loss as to what I should do to fix the flicker.
 
I just noticed with my peripheral vision while looking at my computer that there is a little bit of a flicker from the led lights while it is on shore power.  The flicker is not noticeable when looking directly at the lights.  It is very noticeable and annoying when using the generator. 
 
What kind of converter do you have?  Most converters have active filtering built into them, but there are a few older ones that don't - they convert the incoming AC to pulsating DC and feed it directly out without any kind of filtering.

If you have one without filtering (what kind of a converter do you have?) your LEDs will pulsate at 120 Hz when you're plugged into clean shore power.  This is too fast for the human eye to see, so everything looks fine.

Few RV or portable generators put out power as clean as what you get from the local utility, so if your converter does not do any additional filtering (again, what kind do you have?) you'll get additional flicker as the DC voltage follows the generator's pulsing power.

If your generator's voltage varies outside it's spec, the answer is to fix the generator.  But if it's within spec, and you don't have an electronically filtered converter, the easiest solution is to upgrade your converter to a more modern unit that has an output that remains constant as the incoming AC voltage changes.
 
I've never owned a MH or an onan but do you know if they use a neutral ground bond or if it's provided through the transfer switch? RV's are not bonded but some generators such as Honda and Yamaha are floating neutral so I'm just wondering if your Onan is. Honda owners will sometimes use a n/g bond plug placed in one of the 20 amp receptacles so their EMS units operate as if they are on shore power.

It doesn't hurt to look at that issue or try it if a n/g bond isn't supplied by Onan. It may not have mattered when using incandescent bulbs but may be a cheap fix if it helps led????

http://noshockzone.org/generator-ground-neutral-bonding/

https://www.google.com/search?q=g-n+bonding+plug&sa=X&tbm=isch&imgil=31TUjqo0bf_NEM%253A%253B-RhQHz7xawn9_M%253Bhttp%25253A%25252F%25252Fwww.doityourself.com%25252Fforum%25252Felectrical-ac-dc%25252F490120-generator-bonding.html&source=iu&pf=m&fir=31TUjqo0bf_NEM%253A%252C-RhQHz7xawn9_M%252C_&usg=__35LksKqAQNEiA7pAmNSAdaTXMqY%3D&biw=1266&bih=636&ved=0ahUKEwi8opXW78HWAhViz1QKHUipAM0QyjcIggE&ei=gsTJWbzZMuKe0wLI0oLoDA#imgrc=Gia1aEdz4R8IIM:
 
Gary is correct about working good on shower power in judging the converter. Take the MH to an Onan service center and have them check the rpm vs Hertz output. Your convert is designed to filter 60 cycles and your generator is probably putting out much more or much less.
 
This is not something you fix by swapping parts willy-nilly. You first have to figure out why the genset power is causing a problem. Something is different about the genset as a power source and have to figure out what that is.

A simple and cheaper way to start the diagnosis might be to use a VOM to check the genset voltage & frequency, at idle and under load.  If you don't have one, a friend might be able to help. The meters are cheap these days. Or get a Kill-O-Watt device to plug into to an outlet - it reports voltage & frequency as well as other parameters. About $20 and no special skills needed.

https://www.amazon.com/dp/B00009MDBU/ref=asc_df_B00009MDBU5187964/


As for the rest, an Led "bulb" is an electronic device and works on an entirely different principle than an incandescent bulb. The actual diode that emits the light is very sensitive to voltage and current, both the amount and quality, and the tiny circuit board inside is there to regulate the power to meet the needs of the little diode. To the extent that the circuit does a perfect job, the led works great. If the circuit can't cope with the incoming power, blinking - or no light at all - is a typical result.  You might try a different brand of led bulb in a couple fixtures to see if they react the same way.
 
One qick test is to check the voltage at the light with your meter set to AC volts.  This may tell you if you have ripple voltage coming through the DC line.
 
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