Compressor onboard through inverter?

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Anyone have an air compressor onboard? In the middle of an extended refit I'm getting quite fond of air :cool:
So since the compressor will somehow need to get stashed it would be great to have it working back on the hook - polisher, needle gun, sprayer..
Looked at engine mounted compressors but that just seems a bit silly - so what about through an inverter? Only data on this one says 2.5Hp, which looking at others on google seems to be about 2Kw or bit less, so would an inverter like this one have enough oomph to get it started, & is it any good anyway?? Price seems OK.

https://www.sunshinesolar.co.uk/Item/VP3000

3000W, 6000W for 2 sec, 4500W for 10 sec

Think it's this compressor >
https://www.aki.pt/ferramentas/equi...l/compressorcomoleodexter50l2.5cv-p44693.aspx

ta

edit - just put a clamp meter on the input, with the not great boatyard LX not quite enough to get it going with sir still in the cylinder so just an no more stalled motor it was pulling just under 14A, down below 5A when running. So maybe..... :)
 
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I do have a small air compressor on board but have never tried to runit from an inverter as I think the inrush current will be very high and would trip the inverter.

I only run mine from shore power the same as my dive compressor, and mains water maker
 
Rogershaw said:
I do have a small air compressor on board but have never tried to runit from an inverter as I think the inrush current will be very high and would trip the inverter.

I only run mine from shore power the same as my dive compressor, and mains water maker
Click to expand...


Data sheet says 6000W for 2 sec, so might be ok.... ?
http://www.sunshinesolar.co.uk/media/ecom/html/VP3000.pdf
Though getting enough amps going in could be too much of a hurdle, even with 120A alternator running...

Need a new inverter anyway, that price seems good if the unit is OK - anyone tried this brand?
https://www.sunshinesolar.co.uk/Item/VP3000
 
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Have a look at variable frequency speed control/soft start.

You can the use a 3 phase motor from a single phase supply. Yjos would also allow you to start the compressor at low speed and increase the speed as required.
 
For what it is worth, my 15 cu ft compressor has a similar size electric motor, and the old 3.5 kva generator struggled to start it on a cold day. motors take a lot of beef to get going.

running compressors take a lot of power, so you need big batteries to keep it running for any sort of job.
 
I was looking into electric dive compressors on board, and theres a huge and very informative thread over on cruisers forum (if you do a Google search it will come up). It is possible but complicated.....
 
i have a Coltri dive compressor. It is fine off the Genset but would be too much for my inverter, never mind the start up but also for the 30 minute run time for a cylinder. Aside from that it works great and perfect for I guess up to four people wanting to do some diving off their yacht.
 
OP should revisit the idea of belt drive from the engine. A few brackets a belt and perhaps an additional pulley on the crankshaft. Or perhaps find a DC motor that might do the job. Still a lot of current from 12v. If he does go inverter make sure it is "pure sine wave" as in the link. ol'will
 
Lots of truck compressors available driven from the engine.

An air con car compressor could also be used for air depending on the presser and air flow needed.
 
Rogershaw said:
Lots of truck compressors available driven from the engine.

An air con car compressor could also be used for air depending on the presser and air flow needed.
Click to expand...

Any links anyone? Google doesn't come up with much - would these need a tank and some sort of auto on/off sitch to regulate the pressure?

Not sure there's enough room round the engine to squeeze something in but well worth a look.
 
Yes you will need a tank and pressure switch.

My first air spray compressor was a oil free diaphragm compressor with a tank from a truck scrap yard

I would also look for a truck compressor from a truck scrap yard.

I found lots by googling truck air compressor.

Some diesel engines do have a power takeoff my PRM gearbox had an attachment for a power take off to drive whatever you wish. I am considering fitting a hydraulic pump to drive my bow thruster rather than electric. It would also allow me to have other hydraulic actuators.

Hydraulics can also be used to drive a mains alternator to any mains driven item and the hydraulics can be setup to control the mains frequency irrespective of the engine speed.
 
Compressed air is a very inefficient form of power, even if you prefer it.
And when available power and space are limited (because of batteries, alternator and/or other limitations) it's really not the best solution.

When equivalent electric power tools are available and are far more efficient, quieter and for this application, more manageable (cordless etc) it would be a much more sensible way forward I would suggest.

I think when you look into it in depth you'll find the initial surge current of a compressor motor, particularly when under load, is just too much for most inverters, and it just isn't an economic proposition.

Research cordless battery power tools instead - much simpler, very effective and probably a much cheaper option overall. As well as safer with no trailing leads or hoses.
The you could use a high volume low pressure compressor with no receiver just for the applications where you have to have compressed air (eg spraying or blowing down).

Just my two penneth :)
 
Rogershaw said:
Have a look at variable frequency speed control/soft start.

You can the use a 3 phase motor from a single phase supply. Yjos would also allow you to start the compressor at low speed and increase the speed as required.
Click to expand...

Exactly my thoughts Paddy. You might even invent a compressed air steering system lol How novel :)
 
david_bagshaw said:
For what it is worth, my 15 cu ft compressor has a similar size electric motor, and the old 3.5 kva generator struggled to start it on a cold day.
Click to expand...

Can't quite see how the motor is the same? This compressor is 205 litres/min or 7.2 cfm, 8 bar, only data for motor(?) is 2.5Hp, clamp meter showed nearly 14A with a stalled motor trying to start with cylinder full, didn't check while pulling the release valve which some days is the only way to get it start on not great boatyard power.
 
So ignoring the compressor for a moment, has anyone got one of these? Tempted to go for one at that price anyway but would be nice to know if it's OK

aLcFNRI.png


https://www.sunshinesolar.co.uk/Item/VP3000
 
You are probably well aware, but dont overlook that an inverter is very efficient at draining your batteries very quickly! Do not underestimate its ability to do so. Also do not underestimate the load it will place on the house bank. Some batteries do not take well to high loads. Finally specifiy the correct gauge wiring to the inverter is vitally important. All that aside a very useful item.
 
ip485 said:
You are probably well aware, but dont overlook that an inverter is very efficient at draining your batteries very quickly! Do not underestimate its ability to do so. Also do not underestimate the load it will place on the house bank. Some batteries do not take well to high loads. Finally specifiy the correct gauge wiring to the inverter is vitally important. All that aside a very useful item.
Click to expand...
Well aware :) Getting enough amps out of the batteries might be the killer, even with 120A engine alternator & 20A mains charger off genny running. A spare lithium might be cheaper before too long though....

But would be handy once in a while just for the hoover or something without digging out the genny even if running the compressor turns out to be a dead end.
 
Well Lidl did good :cool: Various nozzles/gun, shot blaster, spray gun & air polisher the other day for about €60, never has the dinghy been pumped up so quick! Don't think many peeps here know what it's actually like to live on the hook, having air at the turn of a button would be just fantastic!


So the only real question is - can 6Kw for 2 secs & 4.5Kw for 10 secs get a 2.5Hp compressor up and running... or is it worth another £120 to go for a 4000W inverter...... hmmm....
 
May I politely mention that compressors should be started off load, ie with the pistons not squashing any air but venting to the atmosphere through a manual cock, which is closed when the compressor is running at full speed. DIY and 12v car tyre compressors may not be arranged like this, but it will greatly reduce the momentary start-up load on your chosen power source. Also open said valve before stopping the compressor.
I wouldn't bother in a 10m sailing yacht personally, I know your boat's steel, and air tools are great for doing steel maintenance..if you have enough air.. DIY compressors struggle to run a needle gun continuously, air grinders use a lot of cfm as well. And all the gear and fittings will rust in 5 minutes, not being meant for salty conditions.
Don't mean to be a wet blanket, I have done untold amounts of steel maintenance on ships using air tools, but to me it does not compute on a cruising yacht.
I'm sure you know there are ways and means of running nice cordless tools from the ship's 12v DC system, which I believe to be the best way to go, on the hook.
 
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