Inverter

   / Inverter #1  

Lloyd_E

Veteran Member
Joined
Nov 15, 2003
Messages
1,498
Location
South Shore Nova Scotia Canada
Tractor
2008 Kioti DK 45 sc
Anyone using an inverter on there tractor?

I have a 700 watt inverter that I would like to use with a power drill from my tractor.

Any concerns about this?

TIA

Lloyd
 
   / Inverter #2  
Inverters are VERY in-efficient. Check how much DC current is required to make 700w AC and I think you will find that your battery and alternator will struggle to keep up.
 
   / Inverter #3  
The other concern is around durability. If you are going to permanently mount it, you might consider a marine grade inverter.

Also, make sure the inverter is directly wired (and fused) to the battery with the proper size fuse and wire

For your 700W inverter, I doubt there would be an issue for occasional use. Might be a different story if you're using it to drive in a full deck's worth of screws.
 
   / Inverter #4  
quick math move the decmal point to the right one place.

drill 5 amps at 120v ac excluding invertor losses ect. 50 amps at 12vdc

most likely for a couple holes battery would put out that much but what size is your alternator? to recharge battery

tom
 
   / Inverter #5  
This subject has been discussed several times - do a search on "inverter".

Quick answer is that an inverter can provide a handy 110 volts for a small job, but it takes a lot of current (amps), as has been noted.
 
   / Inverter #6  
Watts are watts regardless of the source. Power in watts = Current times voltage. So power divided by voltage = current. 700W divided by 12VDC = 58 amps. Modern inverters are getting pretty efficient. Lightly loaded ones are less efficient. At full load, a modern inverter is probably better than 90% efficient. But that efficiency also needs to be taken into account, so instead of 58A to make 700W, you need closer to 65A to make 700W thru the inverter. At 12V, this ammount of current also takes really large wire.

Unless your alternator is greater than 60A output, it will see this load like a short, and do it's best to fill the hole this size load creates. The battery will buffer this load to some extent, but ultimately the energy has to come from somewhere. Alternators run beyond their max capacity don't live long.

Drill motors are inductive devices. Inductive devices draw the majority of their energy from the peak of the AC sine wave. Unless it is a high end inverter, it is probably a modified sine wave type, or worse, a square wave type. A modified sine wave is a series of square wave signals stacked to resemble a sine wave. But since it is not an actual sine wave, the drill will be less effiient and draw more power to perform the same ammount of work...

What does a new alternator cost, plus labor to install it? I would guess that you can get a real nice cordless drill and a few extra batteries for that same cost. You will also not have to worry about cords and such, as well as properly wiring a 12V inverter to your tractor. The drill will also be usefull elsewhere. Once you have the batteries and charger, you can also add tools that use the same battery packs. I have a 19V sawsall that I am really impressed with. I even put it on a pole, and use it to limb trees...

Good Luck.
 
   / Inverter #7  
The alternator has no problem regardless of its size. The voltage regulator limits its output to its safe capacity.

I have been running 1000W inverters on 3 tractors including the BX for4 yrs each. NO alternator problems. And no problem deadening the battery unless your demand is high and frequent-or long term like cutting an 18" dia log. There is also a low V cutoff at about 10.5V built into the inverter electronics that cuts it off when it senses voltage below that threshold. Due to this, the only way you could badly discharge a battery is drain it with very light inverter demand. Heavier demand pulls the voltage under load down much sooner and the inverter will kick off when the batt still has about 50 or more % charge.
larry
 
   / Inverter #8  
The alternator has no problem regardless of its size. The voltage regulator limits its output to its safe capacity.

larry

Larry, a voltage regulator in an alternator knows only one thing, and that is to make 14.5VDC. IF the load pulls the voltage below this point, the voltage regulator increases the field current to boost the output to get back to 14.5V. If it is unable to reach that voltage, the alternator will output at MAX capacity untill it does reach that voltage. There is a current limit circuit on the field circuit that keeps the alternator from frying immediatly and limits the output to the max rateing. Alternators run at their max output do not last as long due to heat and bearing loads...
 
   / Inverter #9  
Larry, a voltage regulator in an alternator knows only one thing, and that is to make 14.5VDC. IF the load pulls the voltage below this point, the voltage regulator increases the field current to boost the output to get back to 14.5V. If it is unable to reach that voltage, the alternator will output at MAX capacity untill it does reach that voltage. There is a current limit circuit on the field circuit that keeps the alternator from frying immediatly and limits the output to the max rateing. Alternators run at their max output do not last as long due to heat and bearing loads...
V regs dont just slam the alt on and off they taper the field from near off to full excitation depending on the battery voltage. They do not go wide open up to 14.5, but taper to that as a max float voltage. The better ones go one better, charging to ~14.5 and then allowing the V to subside to around 14. This is healthier for the battery.

That however is not really very important to this conversation because this is based on long term experience using 1kW inverters on tractors with alternaters with capacities in the 15 to 35 Amp range. In a 4 year period each of them has tens of hours of inverter time. Not a single alternater has malfunctioned.
larry
 
   / Inverter #10  
V regs dont just slam the alt on and off they taper the field from near off to full excitation depending on the battery voltage. They do not go wide open up to 14.5, but taper to that as a max float voltage. The better ones go one better, charging to ~14.5 and then allowing the V to subside to around 14. This is healthier for the battery.

That however is not really very important to this conversation because this is based on long term experience using 1kW inverters on tractors with alternaters with capacities in the 15 to 35 Amp range. In a 4 year period each of them has tens of hours of inverter time. Not a single alternater has malfunctioned.
larry

No one said they slammed on and off. only YOU made that comment in your off reply.

I agree with the other poster.. the alternator running at max output for prolonged periods of use will not last long.

if it is a decent storage battery, the OP should be able to get some decent usage out of the small power tool with the tractor off and just using the battery, leaving enough for starting.. etc.

I've run parade routes with a couple inverters running xmas lamps and illumination lamps for the passangers.. I usually tie in an extra 'car' battery on the trailer tounge, and hookup marker lamps and flashers for the trailer. Don't have any problem in running a 1 hr parade with lamps going...

soundguy
 
 
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