Power inverter for the Framon #2

you're using to

about 400

Framon is correct.

if you want ample power for most situations ? you could use a minimum of 1200 watts. would suggest 1600.

g'day

Usually inverters can handle the start up load. One thing to consider when buying an inverter is the quality of the power. Some of the cheaper ones do a piss poor job of imitating a sine wave. It is likely that sometime you will need to run some kind of electronics and the cheapo units will wreak havoc with some circuits.

Most inverters have a surge rating which is usually about double the operating rating. For an application under 1000 W or so just get double what you you need with regard to both numbers. The cost will not be that much greater.

I use a 1,000 watt inverter in the van to run my ITL code machine. It will also run a grinder, 750 watt hammer drill, as well as most other electrical tools. But ....... . next time I purchase an inverter, I will upgrade to a

1,600 - 2,000w model as drilling large diameter holes does tend to 'suck the guts' out of the 1000w inverter. More power to ya !

Matt --

You can calculate amperage by multiplying voltage * wattage. The framon has a 2.7 watt 115 volt motor which comes out to 310.5. The framon 2 or at least the one I had uses an "induction" motor which according to some of the inverter mfg's I spoke with can surge up to 7 times the amperage draw at startup. (2174)

I tried my 400/800 then bought an 800/1600 and neither of them worked with it. I spoke with some people that were able to run it on a 1200/2400 the price of which I found unacceptable considering that I don't care to run anything else off of the inverter. So I purchased a 12 volt motor and run it off of my cigarette lighter. The motor I got was an actual Framon 12 volt motor off of eBay, but prior to seeing that I was looking at the Keedex one (around $50) that I heard great things about.

Hope this was helpful.

-- A

I tried my 400/800 then bought an 800/1600 and neither of them worked with it. I spoke with some people that were able to run it on a 1200/2400 the price of which I found unacceptable considering that I don't care to run anything else off of the inverter. So I purchased a 12 volt motor and run it off of my cigarette lighter. The motor I got was an actual Framon 12 volt motor off of eBay, but prior to seeing that I was looking at the Keedex one (around $50) that I heard great things about. "

First off Absinthe you are using the WRONG formula... There is no such equation (amperage = voltage * wattage) in Ohm's Law... The correct equation is (amperage = wattage / voltage) however since your goal is to figure out the power demand (wattage) you are using the wrong formula to begin with... Your figures only make sense if you plug them into the formula (wattage = voltage * amperage) since that is what you were trying to do, figure out the wattage... Perhaps you read the little plate on the motor incorrectly or just jumbled up the formula...

Second your numbers will be slightly off given that most inverters will give you 125 VAC @ 13.8v DC supply when the vehicle is running -- I don't recommend using an inverter with the engine off because doing that over time will shorten the life of your car battery dramatically, especially if you intend on using your appliance for longer than a minute or two... Something that only draws 3 amps on 120 VAC power will draw 10 times that amperage in

12v power on the other side of that inverter from your car's electrical system... AC power from a wall outlet can be anywhere in a range from 110 V to 130 V... Any lower or higher than that range (+/- 10 volts) and you will begin having severe difficulties using anything electronic...

Why you tried running this machine off your 400watt inverter baffles me, since you knew that it surges when you turn it on... Then you went out and purchased another inverter with a slightly higher power supply rating, yet still not enough for what you wanted to do... But you totally ignored your own calculations for surge demand... If you knew that the surge demand for this appliance was roughly 2200 watts then you should have selected the third inverter rated 1200/2400... The surge capacity of this inverter of

2400watts would be able to handle the motor startup on your Framon code machine... When you go out looking for inverters to run power tools you are more concerned with the peak surge demand rating of the inverter rather than its constant power output rating...

Evan the maintenance man...

Evan --

You are correct, in that I stated the formula incorrectly. The Framon 2 has a 2.7 amp (not watt) motor. What I meant was what you said to calculate watts being amps * voltage = watts.

However, the point I was making was that when I came out with 310 I saw no reason why the 400/800 shouldn't have worked. *UNTIL* after I got the

800/1600 and it didn't work did I begin to research it further and found that the surge could have been up to 7 times as high as the draw for an induction motor.

Most of what I had heard was to "figure out your draw, then double it" and that should work. Must be some kind of common knowledge that is just plain wrong, or perhaps a good rule of thumb for most things, just not what I wanted to do. I Just sort of guessed, perhasp it was a little more than double and triple seemed fair to my sensibilities. Well, when that didn't work I talked to some electronics people to figure out why everything I knew was wrong. And perhaps I was doing the formula wrong. They explained that if you are using an inversion motor that the potential of up to 7 times the draw for initial surge comes to play. At that point I realized that 2174 would be a better value.

When I weighed my options I could find a 1200/2400 that might have worked but it was $169 and I was going to have to figure out some way to wire it to the battery or something, and a motor was only going to cost me around $50 so I opted for the motor.

I operate out of the back of a Jeep Grand Cherokee so space is at a premium. An inverter may not take up "too" much room, but if I don't need it I would prefer not to carry it in deference to something I may "need" to carry, as it takes up as much room as my two Autosmart books. So, many things went into my decision not to use an inverter, but that's me. If the day comes that I convert to a van of some kind I will no doubt get the biggest inverter I can afford and run all manner of things off of it, but for now everything I run is either battery powered, or maual, or plugs into a cigarette socket..

Thanks for correcting my equation terminology. PIE right? P = I * E (P = watts, I = amps, E = volts)

-- A

The correct formula is Watts=Amperage X Voltage. Or Amperage = Watts/Voltage. Or Voltage = Watts/Amperage.

And, to get finicky - be sure to include the Power Factor (which is the cosine of the phase angle between the voltage and current sine waves

- or something equally useless :-) in those calculations. Motors can have a significantly low PF.

This may be important in specifying an inverter - usually people don't worry about the PF per se, but specify the HP than can be supported, as well as the wattage.

Thanks for all the responses.

I'm hoping a 1000/2000 inverter will do it. I heard of someone using an 800/1600 that worked for them but they had to help the motor start by turning the cutter. I'm hoping I won't have to do that but we'll see.

I thought about the 12 Volt model but I figured it wouldn't have the power of the 110 V. Most cigarette lighters use 15 Amp fuses so manufacturers stick to that as a "high" point. That only gives 150 to

200 watts output, where Framon told me the #2 pulls about 400 Watts. I also need to use it inside, and I've got a good 12 V power supply but it supports up to 12 amps continous. I'm curious, what does Framon's 12 V motor run at (amps)? Also, is there also a real high surge on startup like there is with the 110 V?

Thanks again for all the comments!

The Framon 2's 12 volt motor is 9 amp. I run it from my cigarette lighter and have not popped a fuse yet. I have cut many keys some of which even have very deep cuts. It is a 1/10 hp motor, which is slightly stronger than the

110 which is 1/12 hp if that matters. If in fact it surges to any degree it doesn't do so to the point of blowing any of my fuses.

Just as an example of one job I did on it, I had 10 SC4's to cut to the same code. I never turned the machine off the whole time, just kept switching the keys to make all the same # cut, then adjusting to the next position and depth and switched all those keys though. No wires got hot, no fuses got blown, and the motor didn't "bog" to any significant extent even on particularly deep cuts.

As for the difference I could see, the 110 motor "jerks" when it starts as though it is spinning right up to the highest speed right away. The 12 volt motor seems to start a little smoother and take a few seconds to spin up to the highest speed. That is from memory though, and I could be mistaken in what I remember. They are both very nice motors. And both of them seem to cut quite well.

-- A