Kill-a-Watt & 1986 Onan 4.0 BFA

Hi PT,

The “nearly 4000 watts” that I expressed was based on an estimate; Coleman A/C plus 1500W electric heater. The KAW is merely plugged in to a separate outlet reading the voltage, frequency and power factor; no current or wattage.


Hi KJINTF,

Well that’s a generous offer. I might have to take you up on that.

Interesting to hear your recollection on the O-Scope. I was under the impression that the wave was not so smooth. I’ll have to read up on that.

Also, I don’t believe she has an oil filter. I just do yearly oil changes in Fall, regardless of use. I might put 2 or 3 dozen hours a year on her. Some of that for exercise; much for the A/C while driving down the highway on hot summer days (the chassis A/C needs a recharge, but I prefer not to add any more heat to an already maxed out cooling system anyway.)


Good morning, weighty,

Thanks for sharing that. I’ll keep the KAW away from that inverter going forward.


Good morning, Matt,

Good to know all that. Thanks!


Hi j-d,

Yes, I am also not aware of any electronics on her.

And yeah, my father has been clamoring for one as a backup home genny. They seem to garner much respect for their longevity and value. The original owner of mine kept impeccable records and changed the oil WAY more often than I would. I covet the modern, quiet, diesel and LP units, but the old girl does run well. Plus my old RV has almost no parasitic draw and 3 group 27s, so I almost never need to run the Onan at a quiet campsite anyway. Just did a 3 day Memorial weekend dry camp and the bank read just under 12.5V when we were packing up Monday morning.

Most of the Onan’s use is highway A/C and occasional campground A/C when needed. Otherwise the alternator does most of the charging on the way home. The Onan gets way more use from exercising her in storage than she does charging batteries. Oh… and for the occasional hair drying session when I take Mrs. P to some gala affair in another town.

RJCorazza wrote:
I had an Onan BFG, and if memory serves the frequency was directly related to engine rpm. Mine was gradually rising in voltage into the 130-140 range while maintaining the 60hz. I replaced the circuit board with an aftermarket control board made by Flight Systems (dinosaur board?) which fixed the high voltage problem. Your BFA genset may be totally different, but I believe the frequency is still directly related to rpm.

should be, yes

SCVJeff wrote:
And the output is showing 135V w/ a 4kw load?

Not quite. Just over 130 under a full load as measured by the KAW.

The 135 was the KAW plugged into the inverter. No load.

Here's a BFA in all its glory. The one we had was built 1982 and to my knowledge it had Zero Electronics. The 1800 RPM governor set up both Voltage and Frequency. A big, heavy, overbuilt beast that will run forever given a little maintenance. A friend shipped one to Hawaii where it provided power for a group of small homes for decades. Probably still doing it.



KY's are a mechanical joke. Quieter but costly in the long run.

My coach has a BF 4.0. The output is clean and the unit is very stable. I keep a KAW and an extension cord in the case I have to tweak it (altitude).

I also have a 1Kw MSW inverter. They lie. It is not a Modified Sine Wave, it is a Modified Square Wave. I do have an O-scope and have looked. As best my expensive instruments can figure it is about 50% distortion. (This could make speech unintelligible.) Indeed, the KAW Freaks Out when I try to use it on the inverter power. I do not believe that either of mine (I have two different models) are true RMS. I say this because my Flukes that are true RMS give me different values.

Matt

What I read about the Kill-a-watt is that if plugged into a MSW it may tend to flame on (Well smoke)... I know it works well with my True Sine Wave.

There are two different types of voltage dividers used in meters. Capacitive and resistive and the capacitive ones may respond differently to the different waveforms.. I would not know which to trust less I tested with calibrated meters and calibrated them on both waveforms.

KJINTF wrote:
Kendall
...
Does not run as smooth as the older twin did

They weren't named "performer" for nothing!

Kendall

Your 4Kw Onan genset is a good machine
Two cylinder, pressurized oil system with a spin on filter
(Got a few extra parts if you want them)
Had one for many years in a 1986 Itasca 24ft Class C
As i remember looking at the waveform many years ago it looked clean on a O'scope

My new RV came with an Onana Speck K 4Kw genset - what a POS!!!!!!
Single cylinder splash oil system with out any oil filter at all
Does not run as smooth as the older twin did

Hi KendallP,

How are you measuring 4000 watts with a Kill-A-Watt? I thought the limit was 1800?

I had an Onan BFG, and if memory serves the frequency was directly related to engine rpm. Mine was gradually rising in voltage into the 130-140 range while maintaining the 60hz. I replaced the circuit board with an aftermarket control board made by Flight Systems (dinosaur board?) which fixed the high voltage problem. Your BFA genset may be totally different, but I believe the frequency is still directly related to rpm.