3Ph/415v Generators for workshop..

[GnuBee]

The rented workshop I have does not have 3 phase and the landowner is not keen on a reconnection (also not sure I want the standing charge/minimum consumption). Workshop is not used full time - probably average around 10 > 15 days a month.

At the moment I end up converting machines to use 220v 3phase via digital inverters but I'm at the work envelope for a couple and need to move up a level. Been looking at generators in the 10 > 15KVA range (but have to admit it's been a finger in the air guesstimate based on anecdotal research and fag packet "calcs" - maximum of say 7HP lathe or 5hp + 2hp mill and not both running at the same time)

Few questions if there are any resident generator experts though:

1) Can you run a welder off a generator safely ?- mate has a 400A TiG; he's not going to be pushing it to its limits though

2) I can go new with something like a KIPOR KDE12STA3 and hit a price point of around 2.5k or do I go second hand (for example watching a 21KVA open frame diesel job which is gradually reducing in price)? I can see the benefit of a warranty etc but is there anything specific that a new one would bring; better control, voltage regulation etc?

3) What are they like maintenance wise?

4) Finally I'm not wrong in assuming I can run one on red diesel am I?

Thanks in anticipation

[GnuBee]

Hi, thanks.

It's not the sole supply - there's already a 220v supply and that's handling lighting, smaller tools etc. This will be purely used to power larger machine tools; mill, lathe etc - I'm not going to using anything bigger than 10HP at any one time - and even that's unlikely.

Installation will be discrete, there'll be absolutely no chance of a cross connection as we'll be running completely new and separate wiring and panel.

I've been watching prices for the last 2 - 3 months; huge difference between an open framed, skid mounted thing that's been backup at a small workshop etc and nice modern painted item on a fast tow trailer. That's the dilemma - I can get the KVA at even sub 1.5k but it'll be an older generator or I can hit 2.5k for 12KVA modern set (the 400A welder will never be used at full capacity + it's a nice to have not an absolute).

Cost is a factor but it'll still be cheaper than running 3 phase connection from the local supplier and I'm likely to have to move in a couple of years so having "portable" 3 phase is very attractive.

[GnuBee]

Thanks - that very useful information, really appreciate that. I had the same concern about "fast tow" generators - look like a great way of making it easy to steal.

[GnuBee]

C Lee Farquar said:

If it's of interest I had my supply upgraded to 3 phase last year. It cost £680 plus VAT and I retained my existing fixed rate and standing charge.

I've spoken to the landowner and he's not prepared to allow me to get it re-connected <- yes this is the supreme irony; the workshop is on ex-commercial premises that used to have 3 phase.

That combined with the warning that he's expecting to sell within the next 2 years is really dictating the direction here.

This makes him sounds worse than he is; we pay very little for our facilities (pay nothing for electricity or water currently for example) and have the advantage that like many farmers he's armed and always suspicious of people on or near his land.

[GnuBee]

Scuffers said:

only issue with open frame skid gensets is they tend to be somewhat noisy, fine if you can park it out the way, but you really don't want to be next to one.

More modern enclosed ones are much easier to live with, but remember, they still need to be well ventilated - 20Kva gen will be putting out ~40Kw of heat (between the radiator and exhaust), that said, this can be quite useful for heating a shed in the winter!

400A two phase welder - what exactly are we looking at here?

if it's an industrial type genuine 400A, then 20Kva is not going to cut it, as you have to consider that they are not a 3 phase load, it's running 1 phase delta - 415V, and the genset is rated on loading all 3 phases reasonable equally.

400A @ 60V is 24Kw just to start with.

I know nothing about welders so all I can tell you is it's some huge behemoth of a blue box, previously used fabricating parts for Lister cars. The welder support is very much a nice to have; I don't need it as my interest here is purely in supporting my machinery - supporting a welder is purely something for my friend - he'd be using it to do typical car bodywork type activity; not welding small container ships together.

The heat point is valuable - I was hoping it would be like that as I'd be interested in leveraging some of that waste heat for the workshop.

The impression I get from all (the very helpful replies for which I'm very greatful) is that things start getting demanding if I pursue the favour to a friend with his TiG tank.

The noise thing is most definitely a consideration but this is an ex commercial site, a skid mounted set would be outside (under cover).