I don't know whats going on...or...I don't trust my multimeter....

[Dualfuel]

So here it is...we feed our Magnum 2812 with a Honda EU3000i. Everything works great. Honda current passes through to the cottage while the inverter charges the battery bank...
I recently moved the diesel generator down into close proximity of the cottage, and thought it would be great to be able to unplug the Honda and plug in the diesel...except the Inverter does not like the diesel power. The generator is from a Marathon light set. The generator is a Leroy Somer I checked the voltage and found it to be 115 volts.
To help with this dilemma I purchased a Sperry multimeter with a hertz setting. Originally I simply tried to plug the meter into a wall socket...it didn't like it. So I set it up in series with a compact fluorescent bulb to get the amperage down to what I thought the meter could handle....I went on a little spree measuring the hertz of various inverters  and found all to be within a half cycle of 60hz. The I started the generator and when I plugged in the lamp the meter said 438 hertz. This at 115 volts. Hmmmm

I have used this generator for many years now, and thought it strange that the Lincoln stick welder refused to work, nor would the Lincoln mig pack 10. Also it always seemed that the battery chargers never gave much amperage and none would make over 13.6 vdc.

Could it be that I actually have a 400hertz generator head? More likely I simply do not know the proper method of using the Sperry Multimeter...still the generator was originally used in Iraq to power four big flood lights...a resistive load that would not have cared about hertz...I dunno but if the hertz is that far off, it might make sense why the Magnum inverter would reject the incoming AC power.
What do youse think?
BPJ

[Ronmar]

Well to measure voltage and frequency, you should not need anything more than to plug the meter leads into an electrical outlet...  you shouldn't need anything else.  A florescent light uses a switching power supply.  it may be that high frequency that the meter is reading.  A pic of your meter front, showing how it is set and where the leads are plugged into it would help...

[glort]

Measuring Frequency is just like measuring Volts. Connect it to the the power and turn the meter to the appropriate scale ( if you have to). You don't need any load or to worry about what the current is.
I'd get rid of the CF bulb.

If your not sure about the meter, take it back to where you bought it or an electrical shop and get them to do a measurement with it. Also, even though it's new, replace the battery. They can give weird reading if the battery is low.

Sounds to me though if you got 60 Hz or near it on everything else, the thing is probably reading correctly on the generator.
I know a lot of aircraft/ airforce stuff used 400Hz so maybe the generator for lights are the same. I believe there is a power output advantage to the higher frequency and as you said, lights wouldn't care.

I haven't heard of a sperry meter but I have bought a good few cheapie Chinese meters over the years when they have been $7-10 on special at a suppliers.
I have checked most of them with my mates top of the line fluke meter he has calibrated and they are usually 1 point if that off which is hundredths of a volt .  Last time I checked frequency, it was the same, only fluctuation was 10ths of a Hz.

[mobile_bob]

tell us more about this generator?

you might have it sorted out as a 400hz unit, as it is probably made to do dual purpose
that being drive lights and also support for aircraft?

bob g

[BruceM]

My digital frequency meter doesn't read my ST-3 frequency properly.  It gets fooled by some of the spikes typical of the ST heads. I wouldn't be surprised if your meter reading was bogus.

A friendly neighbor with an oscilloscope would come in very handy right now.

[thomasonw]

What they all said - But perhaps most:  What is this Diesel generator?   400Hz is used in Mil, Air, and I know some contractor equipment (We called it Hi-Cycle generators, had to purchase universal AC/DC tools, or special hi-cycle tools...)

Could it be your meter is just telling you the truth and you have a 400Hz generator head?

-al-

[BruceM]

+1 For Ronmar's comment. There is no current draw for a voltage or frequency measurement,  something is wrong if you couldn't get a reading at the outlet.  Stop right there and get that sorted out first.

The CFL can only confuse the issue as they can generate enough EMI to glitch out a cheap digital frequency meter. 

A 400Hz head is MUCH smaller for it's rated capacity, thus their use for aircraft, and it would have to be spun a whole lot faster. Hard to make that mistake, I think. 

[mobile_bob]

often times they are smaller, however they don't have to turn faster necessarily
all that is needed is more poles

it is probably a 12 or 16 pole machine making it useful as a 400hz generator even though direct driven

assuming of course it is direct driven?

just a gut feeling i am having here.

bob g

[Dualfuel]

http://www.leroy-somer.com/documentation_pdf/notices/3664b_en.pdf

The above is my generator head...direct coupled to the Kubota....I have M6 version

Thank you all for the sanity check.

I suspected the CFL bulb when I discovered I got a straight reading by only having one of the meter leads hooked up and the other lead NEAR the wire to the lamp.

The paper instructions that came with the meter said it was fused for a few milliamps on the hertz setting...I didn't believe it at first and plugged it directly into the wall...it didn't work. That's why I went with the CFL...too lazy to look up my basic electricity to calculate which resister I should use in series...

this does bring up the question....How does 400hz affect transformers designed for 60hz?  Like I said, the LS is 6000watts but will not even let the Lincoln buzz box strike an arc, whilst I have been using a cheap Coleman 5000 watt powermate to run it for 20 years. Would the higher frequency not allow the magnetic field in the transformer laminant to build and collapse properly?
I hope you realize that this is a great breakthrough for us here...I have been exploring other generator options for a long time because I have always assumed the Leroy Somer was working properly but just didn't have enough power or flywheel to muscle through the striking of an arc....hence all the hubbub about Kohlers. They have huge heavy flywheels (unlike Briggs). Now if the frequency thing is true...then I really should be leaning towards that big Kohler 15k down the street.
I will investigate further....
BPJ

[BruceM]

Your LS- MS version is not a 400Hz genset.  It's  50/60Hz. 

The meter will not draw any appreciable current connected to the outlet.  There is no need for any series resistor for frequency measurement.  It's just like taking a voltage measurement.  Something else was wrong, you should be able to measure frequency at the outlet.  Perhaps your probes weren't making contact. 

You were right in starting with checking voltage and frequency, but need to back up and check your settings, connections, etc., on the frequency meter.  Check it on another outlet, on a known good AC source.

[Dualfuel]

this does bring up the question....How does 400hz affect transformers designed for 60hz?  Like I said, the LS is 6000watts but will not even let the Lincoln buzz box strike an arc, whilst I have been using a cheap Coleman 5000 watt powermate to run it for 20 years. Would the higher frequency not allow the magnetic field in the transformer laminant to build and collapse properly?

[Tom Reed]

Perhaps the wave form of the 6k unit is really ripply and it's faking out the meter. The welder may not like the wave form either.

[Dualfuel]

****Dumbass Alert!****

http://www.sperryinstruments.com/documents/products/dm6450.pdf

I was reading the manual again....I couldn't magnify the paper manual and was guessing what they wrote apparently...

Anyhow, so the frequency function cannot handle voltage over 30vac....hmmm how does one test a wall socket?

Why is this not easier? hmmm.
BPJ

[XYZER]

****Dumbass Alert!****

Anyhow, so the frequency function cannot handle voltage over 30vac....hmmm how does one test a wall socket?

Why is this not easier? hmmm.
BPJ

The way I do it.......

http://www.amazon.com/P3-International-P4400-Electricity-Monitor/dp/B00009MDBU/ref=sr_1_1?ie=UTF8&qid=1385411034&sr=8-1&keywords=p3+killawatt

[vdubnut62]

Well you beat me to the draw. I was going to say"this would be a really spiffy place for a Killawatt."
Ron.