I have had lots of issues hooking up 3 phase power to my new blacksmithing shed. Its located in a business park that has very old infrastructure and it will cost me just over £ 1000 to connect myself up. I was wondering if i should just buy a generator at approximately the same cost, I only plan on staying in my current position for 5 years and i will be able to sell the generatior after i leave back and recoup some costs. Im running a 25kg Anyang power hammer, mig welder, blower, grinder and lights so i need the power. 

 

Does anyone else rely on a generator? how reliable and have you found it? what were the running costs? can anyone recomend a generator? 

 

Many thanks

 

Andy 

if you are planning to run your power hammer on its own without thinking of anything else, then you will need a BIG genny!  I say this with some authority as my workshop is off grid and it is a royal pain in the posterior!  I have a 7.5KV generator and I can barely run my 16kg angyang. I also can't runa mig welder or standrad arc welder, so had to buy an inverter welder (ie more pricey to buy in the first place), which has to be rated for the size of you genny or lower or it does not work (guess how I know). There will also be times that you won't want to burn all that diesl/petrol just for some lights and a small drill.

 

Just pay the money and get proper power hooked up. t will make life a whole lot easier and cheaper for you! If you can find a bigger genny than I have for a grand, then let me know! I couldn't find a second hand one for less than £2.5k that is any bigger than my lister ST2

Edited February 19, 201511 yr by Dave Budd

200 quid a year to be on 3 phaze ....Jump on it. grid electrics are 14p to 21p a kwhour  (what I have paid last few years)....modern efficient generator 70p a kw hour.....(from internet) other figures as much as £1.20 to £1.50 kwhour.

 

Its a no brainer.

good to know guys, that was pretty unequivical thanks!

Keep in mind the noise a genny makes. You may not be very popular with people with the genny running non stop any time you need power.

I worked in an off the grid shop with a generator for 3 years.  It was hard.  

Imagine you have a profitable job, near deadline and your genny breaks down....it once took six weeks to rebuild a generator we were relying on. That mechanic cost me an untold amount of business; said the rebuild would be 3 days, took it all apart then disappeared for weeks at a time. With the power company you may lose a day now and then at most. 

£1k to connect to 3ph doesn't sound that bad... much much cheaper than the quote my landlady got!!  will be worth it in the long run. 

if it is only for 1 item like a power hammer you could run it on a small petrol or diesel engine though you can often get tools and machinery a lot cheaper if it is 3 phase

if it is only for 1 item like a power hammer you could run it on a small petrol or diesel engine though you can often get tools and machinery a lot cheaper if it is 3 phase

speaking as an electrician in the USA, that is not a bad price for a Service hook up mate. And as alreay stated,  over the course of 5 years that is quite reasonable.

Edited February 20, 201511 yr by Steve Sells

£1000 over 5 years is £200/yr, £4/week, £1/day in round figures.

At a rate of £20/hr, that's 3 minutes/day to check the fuel, oil and water, top-up if needed, start the thing, stop it at the end of the day, sort out the fuel deliveries, maintain it and do all the other assorted faffing about that goes with a generator. You need to be pretty good to get it all done on that sort of timescale.

Even if you cost the time at minimum wage, it's only about 9 minutes a day.

Add in the noise, the need for bunded fuel storage, maintenance, etc and it gets even more convincing.

It has not been mentioned, but mains 3-phase is also much more versatile in terms of what it will run. Inverter drives (VFDs) tend not to like generators very much, if at all. Apparently this is because of the "dirty" waveform and the harmonics. I've certainly had a number of VFDs that simply will not run reliably off generators.

Starting fixed speed motors on generators can be troublesome as well. Direct-On-Line starting a motor draws 6-7 times the rated motor current. Star-Delta start is gentler, but still pulls 2 1/2-3 times the rated motor current. You therefore tend to need a big generator for motor loads, just to handle the starting surge, whereas the mains can generally cope with starting surges without a problem. It may be a consideration if you are likely to want to add to the shop in the future. Hydraulics in particular can be heavy on starting.

 

 

yeah, that's right Tim. Rub it in just how hard done by I am in my off grid workshop     Everything you've mentioned is spot on and then some!  3ph would be amazing to have for so many reasons, but I would settle for mains 1ph if I could get it

a genny is good to have for now and then apps. but factor in fuel, maintenance, and some repair costs, it gets out of hand in a hurry. pushing one day in day out for five years is a tall order even for a big diesel rig. but if you do, get the biggest you can get and get 2 of them, that way you have backup and can rotate gensets time to time and won't be down if one needs servicing.

I live in South Africa where I have 380v 3 ph 80amp supply from our (sadly not very reliable any more) power utility despite it costing more than ( 15k  Uk pounds) to cross the dirt road from the pole say 18 meters. Now I have 3 gensets , 1) 220v 6.5KVA petrol single phase, 2) 380v 10KVA three phase Diesel and 3) 80KVA three phase  Diesel towable. That's lots of capital tied up and lots of maintenance. I make black diesel plants so my fuel is cheap but...... noise is not an issue if you bury a 200L drum in the ground and use it as a silencer (fill one quarter with water , incoming exhaust pipe goes 100mm under water and outgoing starts 100mm below the lid ) all that said if I could get away with 1K for the connection my words would be "who do I pay?"

Hi folks, please excuse my ignorance and diverting the thread but this is a very relevant topic to my situation, so if I ask my question here it will save me clogging up the forums with a very similar thread...

I've got my foot in the door at a new workshop but it's only single phase, I don't have a power hammer or compressor at the minute so am just running grinders, small inverter arc welder, drill press, forge blower, radio, lights...but can foresee myself wanting some a small power hammer and compressor at some point.

What's actually involved in going from single phase to 3 phase? Is 3 phase actually needed for those things? I'm aware of single phase power hammers. I'm ashamed to say my knowledge of electrics is next to nothing. The workshop location will be fantastic for my business (in the grounds of a stately home that's open to the public, my workshop would be next to a successful green wood craftsman who regularly has visitors and the rent is cheap) so I'm really hoping the electrics situation isn't going to be a problem. The workshop is in poor repair at the minute and needs a few months of work to make it ready so the estate manager has asked me for a wish list to bring the spec of the workshop up to scratch for what I need (door sizes/floor/position of windows etc) but this won't include putting in a 3 phase supply so that cost would fall to me.

Apologies blackleafforge.

is there 3 phase in other connected buildings?

if not then a heavy cable needs to be put in to the substation or where the power is distributed from on site, a costly job

a place like that will probably have 3 phase somewhere.

you need a qualified electrician to put it in, red 4 or 5 pin 3 phase sockets, a distribution board and a meter in your place

5 pin means you have 3ph and neutral which some things need, others only need the 3 phases

Lack of 3-phase power is not usually a problem unless you need to run big stuff.

A 3 HP single-phase motor can (usually) be run off a 13A socket. 3 HP is about as big as single-phase compressors get. You can go a bit bigger if you hard-wire to a dedicated circuit with a suitably-sized breaker back at the distribution board and can find a single-phase motor bigger than 3 HP (2.2 kW).

You can use a phase converter to convert from single-phase 230V to 3-phase 400V if necessary, though the power will be limited by the capacity of the incoming supply. A VFD will convert single-phase 230V to 3-phase 230V and the Chinese ones off ebay are pretty cheap (usually under a hundred quid delivered from within the UK) and seem to work ok.

If you can, it's a good idea to get a circuit or 2 put in with industrial 230V sockets and type "C" MCBs which gets you over the 13A limit. If you are running a welder, a 32A socket and type "D" MCB is wise, as the inrush current can be pretty high.

http://www.screwfix.com/c/electrical-lighting/industrial-plugs-connectors/cat830086#category=cat830090

Cheers. There will be 3 phase elsewhere on the estate but not nearby unfortunately. When I used to work out of a shack in my parents' garden I used to run my welder off one of these sockets we had an electrician fit to the exterior of an office that was nextdoor. Can these sockets be fit anywhere with single phase or do the planets need to align in a certain way to allow it?

you need a suitable 32 amp circuit to put them on

Honestly,  one can get single phase motors as large a size as you wish.  I have worked with 700 HP single phase AC motors for example.  But it is more practicle to have 3 phase for bigger motors for more reasons that I want to bother getting into on a non electricians site.

I'll bet there is a noticeable difference in cost between a single phase and a three phase  700hp motor, you'd possibly get lunch for the difference!

You might even be able to get a happy meal and a portaband( adult toy)

try a used car..... Yes that much a dif, and then there are the operating costs...

 

Edited February 24, 201511 yr by Steve Sells