new implement- pto driven alternator for current

[sacsr]

I bought a pto driven "home made' alternator. My plans are to use this as a source of electricity when I am on my hunting land. Primarily it will be used for skill saws, drills, etc...

Single phase synchronous brushless alternator

Type MS100 SE

S1 (KVA) N070935627 60 HZ
3600 rpm
5.0 V A
240 20.8 IP21
120 41.6 PF=1

I don't have alot of money invested at this point.....what do I have?? What can it do?? What are its limitations?? Also came with a 30amp lockable plug.



I have an yanmar 18hp tractor - with 540 and 1000 rpm pto. I am told the guy that had it built had it attached to a Kubota - maybe only 900rpm........

Little late to be asking but my 1000 rpm "over charge" this to damage my equipment??

Any info will be appreciated.

 

[k0ua]

Re: new implement- pto drive alternator for current

Ok I think that is about a 5kw rig, that wants to spin at 3600 rpm on the shaft into the alternator. so I would measure the diameter of the pulleys and apply the ratio. to figure out what rpm the input shaft to the larger pulley is supposed to be spinning. lets say your pto shaft is spinning at 540 rpm (your engine is spinning at whatever it needs to be 540 on the pto shaft) and lets just say the big pulley is 13.3 inches in Diameter and the little pulley is 2 inches in diameter so that is a 6.65 to 1 ratio. then take the 540 x 6.65 = 3591 rpm on the input shaft to the alternator.. close enough to 3600 rpm

If that dont work out then figure out if it needs to going faster or slower than 540 to spin 3600 on the input shaft of the alternator and adjust accordingly. of course you will not be making as much horsepower at lower rpm settings of your engine, but I think you can pull this 5kw device without much problem

James K0UA

 

[zzvyb6]

Now you need a Kill-a-watt voltage and frequency reading meter. I got mine from eBay but I have seen them at Costco. Running lower rpm will get you voltage reduction but then the frquency may be off so much that you appliances will complain.

 

[sacsr]

I measured both pulleys the best I can with them on the unit.

Larger top pulley is 10.25" give or take a little

Smaller lower pulley is 2.5" give or take a little

That comes up to 4.1 ratio.....

My pto are 540 and 1000 - 540 is not enough to reach the 3600 rpm......but that makes the 1000 therefore 4100 rpm the better choice but is this too much??? or does it just stop producing "extra" electricity when the generator reaches 3600 rpm and the higher rpm and electricity is "wasted"???

This is all new to me. I saw Northern Tools had a tool to measure frequency etc....will try to pick one of those up this evening.

thanks,

Scott

 

[zzvyb6]

Here's what you now need to check frequency and voltage simultaneously:

P3 KILL A WATT Power Usage Voltage Meter Monitor NEW! | eBay

 

[wrooster]

Single phase synchronous brushless alternator
Type MS100 SE
S1 (KVA) N070935627 60 HZ
3600 rpm
5.0 V A
240 20.8 IP21
120 41.6 PF=1

I don't have alot of money invested at this point.....what do I have?? What can it do?? What are its limitations?? Also came with a 30amp lockable plug.

What you have there is a 2pole (3600RPM), 120/240Vac split phase, 5KW alternator head. It will require about 8HP at the input. You must operate the alternator head at 3600RPM to get the correct voltages (120/240Vac) and the correct frequency 60Hz).

If you run the alternator head too slow, the output voltage will sag and the output frequency will be too low -- this condition is REALLY bad for motors and devices with transformers. You can burn them up this way, really quick.

If you run the alternator head too fast, the output voltage will be high and the output frequency will be too high. These conditions are bad as well for some types of gear. You should aim for an input speed of 3600RPM +/- 200RPM, which is about 5%. This span of variance will run the majority of typical electrical equipment without problem. In general you are usually better off a little high on input RPM versus a little low.

By the way, the IP21 designation means that the enclosure is drip-proof but you should not store it outdoors nor should you operate it in the rain.

Since your pulley ratios are ~4:1, your 540RPM PTO mode will not reach the necessary 3600RPM at maximum engine RPM. Your 1000RPM PTO mode will reach 3600RPM but at an engine throttle setting less than maximum RPM.

In general, the PTO setup on any tractor is geared such that 540RPM (or optionally selectable 1000RPM) is delivered at the engine's torque peak. In your situation, you will end up running your tractor engine below the torque peak to get the correct PTO RPM for the 3600RPM input to the alternator (approximately 900 PTO RPM in the 1000RPM mode).

In this case I don't think it's a problem at all, as you only need about 8HP to turn the alternator at full load. Your 18HP Yanmar should be able to swing that at the PTO, even with the reduced RPM. The individual who designed the pulley arrangement may have had a similar size tractor (or even larger) and geared the pulleys to take advantaged of the reduced noise/fuel consumption of the lower RPM. In other words, you don't need 30HP at the PTO -- with the engine screaming -- to make 5KW.

In order to set the output voltage/frequency you will need a DMM (digital multi-meter) or Kill-A-Watt meter plugged in BEFORE you attach ANY loads. Start the tractor, come up a bit from idle, engage the PTO in 1000RPM mode, and read the DMM display. Continue advancing the throttle until you have approximately 120/240Vac (depending on where you attached the leads), and approximately 60Hz. Go a bit on the high side. The initial load on the alternator will droop the voltage and frequency a bit as the voltage regulation circuitry goes to work. Once you have the correct output, then you can attach your loads.

Both 120Vac and 240Vac are available on the 30A receptacle. Unless you have a 240Vac load, like a large air compressor or deep well pump, you may not need the 240Vac at all. In that case you can build a cable and external junction box to utilize both legs of the split phase 240Vac on the 30A receptacle.
L1 -> N = 120Vac
L2 -> N = 120Vac
L1 -> L2 = 240Vac

ps:
Always remember to keep the tractor PTO shaft in line as much as possible with the alternator input shaft. Any offset will result in "lumpy" AC as the rotational velocity of an offset shaft drive using universal joints is not constant.

More importantly, also remember that the "open" PTO shaft and pulley arrangement that you show in your pictures will tear your arm off (or worse) in a flash. Pay attention at all times, and do not let children or pets near the apparatus

Wrooster

 

[CharlieS]

I measured both pulleys the best I can with them on the unit.

Larger top pulley is 10.25" give or take a little

Smaller lower pulley is 2.5" give or take a little

That comes up to 4.1 ratio.....

My pto are 540 and 1000 - 540 is not enough to reach the 3600 rpm......but that makes the 1000 therefore 4100 rpm the better choice but is this too much??? or does it just stop producing "extra" electricity when the generator reaches 3600 rpm and the higher rpm and electricity is "wasted"???

This is all new to me. I saw Northern Tools had a tool to measure frequency etc....will try to pick one of those up this evening.

thanks,

Scott

The addition of a volt/frequency meter is advisable, but keep in mind even running the gen off the 1000 rpm pto you'll be running the engine speed up to working rpm's to achieve the 1000 rpm pto speed/4100 rpm pulley ratio you've calculated. which is about 12% overspeed from the recommended 3600 rpm's. Simply reduce engine speed a like amount, thus if your 1000 rpm pto speed requires 1800 rpm's to achive the listed pto speed, reduce engine speed to about 1675 and you'll have the approximate 3600 rpm generator speed required. Then fine tune throttle setting as needed according to the meter readings.
Also note output voltage's can vary 10% safely so for example a nominal 120 volt appliance can safely run on voltages varying from 108-132 volts.
A good example of this is test a home outlet with a good voltmeter and you'll seldom see an exact 120 volts. generally readings will run in the 110 to 114 volt range.

 

[sacsr]

Wrooster,

Great info!! Thanks!!

I have ordered the meter and will use it to monitor the output.

I have other pto drive shafts and will use one of those instead.

This particular pto shaft was in the deal...like you ..the shaft being exposed concerned me.

At this point I have just hooked it up to see if it all "worked".

Looking at your picture ....is yours a generator or alternator?

Why would this alternator have been built rather than a generator??

I bought this off ebay for $75 - so I was figuring I could not get hurt if it did not work out.

Interesting info.....thanks for the info and interested in any other thoughts or suggestions on how to use this.

 

[sacsr]

CharlesS

Thanks for the info. Good to know I am not going to have to change the pulleys and belt. Sounds like it is going to work for what I bought it for.

Just to run small power equipment.....but of course now I am interested in what else it could be used for.

Good info!!

 

[wrooster]

Wrooster,
Looking at your picture ....is yours a generator or alternator?

This is just a terminology thing, don't get hung up on it.

In the past, one might argue that a generator produces direct current (DC), and an alternator produces alternating current (AC).

An alternator, by loose definition, is a device that accepts rotational mechanical energy input and converts it to alternating current (AC) electrical energy output, minus a little bit of losses.

That said, in many "alternator" applications the desired end result is actually direct current (DC); a typical example is an automobile charging system. And in most case these days the rectifier diodes and regulator are incorporated into the alternator itself, so the "alternator" is in fact producing direct current (DC). Yet when you go to the auto parts store you ask the man at the counter for a new "alternator".

Moreover, the term "generator" has come to mean any standalone, integrated apparatus consisting of a power source (e.g. gas or diesel engine) and an alternator. Take the generator to a remote location, add gas, start engine, and the alternator makes AC power just like you would get from your wall socket at home. This way you can sit in the boondocks, swat black flies, and watch baseball on a 54" LCD HDTV via DishTV.

I use the term "alternator" to describe both your and my setup; lacking an engine, what we own could only loosely be described as a "generator". There is no inherent power source, and no way to make power, until you attach it to a tractor. Only then do you have a actual generator. Nevertheless, the people that make the things you and I own may call them an "alternator", or "generator head", or "generator" pretty much interchangeably.

I used a lot of words to tell you "don't worry about it." :thumbsup:

Wrooster