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smitch6
03-08-2011, 08:08 PM
Hi has anyone run their heat press via a generator or inverter before?
if so what type was it?
pure sine, modified sine, etc etc

where we are moored at the mo we have shore power so it's never been an issue, but we are having to move soon and our new moorings won't have shore power so we'll need to have everything converted via the battery bank

my press is 1200w so i should be able to get away with having a 1500w inverter

Ian M
03-08-2011, 08:27 PM
Steve, I think Matt answered your question a bit back so, have a look http://www.dyesubforum.co.uk/vbforum/showthread.php?2435-using-a-generator&highlight=generator

smitch6
03-08-2011, 09:41 PM
ok thanks Ian :) good reading especially as i posted :rolleyes:

yes it has answered it sort of everything will be running through a proper fuse box with RCD's etc anyway i just wondered mainly about the pure or modified if anyone has used either :)

Ian M
03-08-2011, 10:01 PM
lol........I wasn't going to say anything Steve.

Matt Quinn
03-08-2011, 10:08 PM
my press is 1200w so i should be able to get away with having a 1500w inverter

I did indeed, as Ian points out, touch on the question in another thread... An inverter is a slightly different proposition from a generator though.

Your press is an inductive load; it's also likely to present a large surge at switch-on from cold; possibly over 200% of the nominal rated load... So any inverter would need to be a type that can cope with these inductive loads And I suspect I'd be looking more at 2KW for continuous use -

You also need to be VERY aware that wiring this to the boat's electrics is no trivial matter. 2Kw at 230V is 8.6 Amps - at 12V it's 166A and 24v 83A - The inverter needs to be VERY close to the battery bank and will place a considerable drain on it. And By very close I mean no more that 24" of lead connecting to the busbars...

You may be dealing with low voltages; but very high currents... You'd need to make sure the boat's charging system is up to it!

The nearest comparable thing I can think of is film lighting - Nowadays we tend to use low voltage/high wattage halogen or even LED lighting. But it wasn't unknown back in the day for up to 1K - 1.5K of mains lighting to be run from a vehicle... The preferred approach was (and remains) a vehicle-mounted generator for that sort of load...

Camera cars generally do have a seperate auxilliary electrical system like a boat. Sometimes the vehicle has a second alternator - sometimes (as in my own vehicle) just a trio of 100AH charged from an uprated alternator. We do run inverters in our vehicles; but the're purely for charging/running the odd smallish items that need to run off 230v - Audio mixers and the like...

MY instinct would be to see if you can't find space in the engine room or a locker for a generator - Or perhaps a marine specialist can advise on an engine-driven one?

Pure sine wave is always better - it's closer to what a machine generator will produce. The 'square wave' you get off some cheap inverters can upset some switch-mode power supplies - SO is generally no good for computers etc. NOT sure how the little timer/controllers on a press will react to 'crude' A.C.

Ian M
03-08-2011, 10:41 PM
Not wanting to go off topic but, this all reminds me in a way of the old Mr Softee & Mr Whippy ice cream vans. A few years ago I did a bit of research into them & was amazed that they needed quite a powerful seperate car engine in the back just to power the machine for the ice cream etc..

Matt Quinn
03-08-2011, 10:47 PM
Not wanting to go off topic but, this all reminds me in a way of the old Mr Softee & Mr Whippy ice cream vans. A few years ago I did a bit of research into them & was amazed that they needed quite a powerful seperate car engine in the back just to power the machine for the ice cream etc..

'Tis indeed so! I worked on a film many years ago that had an ice cream company at the centre of its plot. There were all sorts of goodies to be stripped out of those vans afterwards that could be put to other uses. Some old Ambulances too has some neat power arrangements and a lot of cameramen used them for that reason.

smitch6
03-08-2011, 11:42 PM
thanks for the replies :)

the trouble is with pure sine they tend to be double the price of the modified ones :(
the one i have is pure and it cost me a fortune but as you said is needed for pc's and our tv and combi boiler etc, so i had to fork out silly money for it.

hard this move and getting me stressed out lol :~

Matt Quinn
03-08-2011, 11:57 PM
Basically you have an oscillator - in this case 50Hz , the output of which is amplified to give you the peak to peak voltage you need... Building a good oscillator is relatively cheap and easy; it's boosting it's output that's the bogey. The cheap approach is to drive the 'amplifiers' hard so they 'clip' and that gives you the characteristic square wave output from cheap inverters... More sophisticated circuitry is needed to obtain the same peak-to-peak output without 'clipping'... THAT's where the cost is.

Ian brings up a good point - years ago you could have got one of the compressor engines out of an ice cream van and just fitted a generator.

Much as I've always wanted one a boat is something I've never owned so I've no practical experience of this. Ultimately you'd need the advice of a marine electrician... But personally I'm inclined to think generator. - Using electricity to produce heat is always inefficient sadly.

logobear
04-08-2011, 03:13 PM
wouldnt you be best running your heat press of any old generator, and keeping computers and printers on inverters for cleaner power?
A 12v battery bank that could supply over 100amps would cost you a lot more than a 2k 240v genny