Single phase power all thats avaiable for new workshop build

[robertl]

Hello Everyone, new to the forum and looking for some advice on a new workshop, i'll explain.
I am planning on building a metal / woodworking workshop (mainly aluminium and stainless steel) for boat work, refurbishment and boat building.
I am a marine engineer to trade and i am planning on starting my own business doing this in said shed.
Now to understand what i will need for this machinery wise, obviously welders, pillar drill, lathe, press brake, guillotine, grinders, table saw, band saw, and anything else you may think on from grinders to anything else with a maximum of 2 people working separate machines at any given time. mostly just be me on my own.
Now the problem is where the shed is going there is no 3 phase within a mile of it. I can get a single phase 100A supply easy enough but not sure how that will work. Basically just wondering if i will get away with a single phase 100A supply and if i end up with 415v 3 phase machines then i can get an RPC which you can get up to 30hp now, The only other issue there is the 30hp rotary converter is 100A so in theory if the RPC was working to capacity that would be all of the capacity on the network. but to be honest looking at the size of motors in the machines i am looking at 10hp seems to be the max. so even with 2 of them there would be still plenty of spare capacity. but im stilll not sure if it is the right way to go.
What are your thoughts on this? the 3 phase would be wildly costly 50k upwards to install so that's out, i could buy land and put the shed elsewhere if it cannot work going forward but i would like to know your thoughts on this.
The land the shed is planned to go on is ours so it will work out a lot cheaper to put it there, just the issue of supply.
Thanks in advance
Robert

 

[James]

Have you considered a generator?
Either diesel or natural gas powered if it’s available at your location.

 

[Andrew Hunter]

How often would these larger loads be required?
Have you considered having an auto start generator fitted just for the 3 phase loads.
If you can get a second single phase supply to the property there should be no problem getting a 3 phase supply and why would you want 2 separate bills.

The re-newable energy option in that location could be a good resolution as you would also be getting some money back if feeding on to the network.

But that all being said all the options are costly so if it is a matter of not being able to justify the expenditure then building closer to a supply or even finding a suitable existing site might be the answer.

 

[DPG]

I think he said the 3 phase option was cost prohibitive due to distance from the nearest 3 phase pole.

 

[Andrew Hunter]

I think he said the 3 phase option was cost prohibitive due to distance from the nearest 3 phase pole.

Would a new secondary supply single phase not be coming from the same place as the three phase supply would need to come from?

 

[DPG]

I might have misunderstood, but I thought he probably had 2 phases available.

 

[Shoei]

Hello Everyone, new to the forum and looking for some advice on a new workshop,...[snip].... I can get a single phase 100A supply easy enough ...
Robert

SSEN specify 100A max for domestic but say 100, 200, 315, 400 and 630 amp for industrial/commercial. Does the single-phase supply have the capacity to be uprated to 200A if you signed-up as an industrial customer? Worth asking the question.

 

[robertl]

SSEN specify 100A max for domestic but say 100, 200, 315, 400 and 630 amp for industrial/commercial. Does the single-phase supply have the capacity to be uprated to 200A if you signed-up as an industrial customer? Worth asking the question.

Have just asked this very question, and the answer was to upgrade from 100A it would need to be a 3 phase supply.
The guy said that 100A was the max they could supply to any property on single phase.

 

[Pete999]

Have you considered a generator?
Either diesel or natural gas powered if it’s available at your location.

From the information you have supplied, sounds like a base load generator is the answer, may be should have considered your load requirements prior to planning the workshop project, whatever choice you take good luck.

 

[robertl]

How often would these larger loads be required?
Have you considered having an auto start generator fitted just for the 3 phase loads.
If you can get a second single phase supply to the property there should be no problem getting a 3 phase supply and why would you want 2 separate bills.

The re-newable energy option in that location could be a good resolution as you would also be getting some money back if feeding on to the network.

But that all being said all the options are costly so if it is a matter of not being able to justify the expenditure then building closer to a supply or even finding a suitable existing site might be the answer.

The larger loads would be infrequent use at best, and i have been thinking about it realistically. the only time that 2 of these things would be running at the same time would be lets say a press brake and guillotine running at the same time.
Now you would be alternating the use, i.e when bending you wouldn't be cutting etc. so even if this were 2 x 10hp motors one would be idling while the other was working so you would never have the load going all at once. or lets say you had the lathe going, you would only be using the lathe and nothing else so i'm now thinking that the single phase will be more than enough to cope.
what do you think with the above circumstances?
and as far as a generator goes, im really not going to go down that route. just another thing to look after and to get a decent one its going to be very expensive.

 

[robertl]

From the information you have supplied, sounds like a base load generator is the answer, may be should have considered your load requirements prior to planning the workshop project, whatever choice you take good luck.

A base load generator would be good, but as i said above i dont think it would be a realistic option price wise to get a decent unit with the power requirements i need.
To be honest i think now looking at the way i am planning to use these machines i.e one at the time. i dont think if i use them like that i will have any issue at all. even using 2 at the time if they were say 5kw each shouldn't be an issue. and as far as any other load goes there will be an LED lighting circuit, several sockets, maybe a radio playing, no electric heating will be installed so the only real load will be the tools and equipment but if only using 1 to 2 of the large units at once i now am starting to think it may be a non issue.
what do you think?
thanks
Robert

 

[Shoei]

Have just asked this very question, and the answer was to upgrade from 100A it would need to be a 3 phase supply.
The guy said that 100A was the max they could supply to any property on single phase.

Is the shed big enough to be split into two 'starter units' that each would need a supply? Agree that 100A is enough to keep a busy workshop running, adding up the worst case usually paints an unrealistically gloomy picture, even in many domestic settings.

 

[robertl]

Is the shed big enough to be split into two 'starter units' that each would need a supply? Agree that 100A is enough to keep a busy workshop running, adding up the worst case usually paints an unrealistically gloomy picture, even in many domestic settings.

Yes it will be 15m long by 10m wide but im thinking ive now written all possible tools and equipment i have and hope to get down and yes if you had 4 of these units running at once it may be an issue but in reality in a 1 to 2 person workshop, even a workshop with 4 or 5 people the chances of having several machines on at once is slim to none. so from that i can be nearly sure it would be less than he 100A or 23KVA available to me.
I'm pretty sure anyway.
If needs be in the future if there was some sort of massive expansion then i suppose 3 phase could be an option

 

[Midwest]

Have you enquired about financial help from the Shetland Islands Council, that they publicise?

Have you enquired if this development would apply?

Financial Assistance

 

[Lucien Nunes]

Are the rotary ones just no good or why dont you reccomend them?

No, it's just a compromise solution. If you have a converter rated for 30hp of load, that has to be running almost idling all the time you want to use a small 3-phase device that can be wasteful. It does nothing to temper the possible heavy starting loads, just makes them bigger and transfers them to the single-phase supply. Then when running, the performance and efficiency of the load motors can be somewhat reduced. An inverter on the other hand can be finely tuned to get the most appropriate starting characteristics for its machine, with a minumum of surge load, and then allows the motor to work at peak efficiency. The main drawback is initial cost, and some motors are not configurable to run from a singe-phase-input inverter.

Would a new secondary supply single phase not be coming from the same place as the three phase supply would need to come from?

As I understand it the transformer feeding the site is single-phase, as is the 11kV overhead line. There might be more single-phase power available from the existing transformer, but to change to 3-phase requires an extra 11kV line and a new 3-phase transformer.

 

[robertl]

No, it's just a compromise solution. If you have a converter rated for 30hp of load, that has to be running almost idling all the time you want to use a small 3-phase device that can be wasteful. It does nothing to temper the possible heavy starting loads, just makes them bigger and transfers them to the single-phase supply. Then when running, the performance and efficiency of the load motors can be somewhat reduced. An inverter on the other hand can be finely tuned to get the most appropriate starting characteristics for its machine, with a minumum of surge load, and then allows the motor to work at peak efficiency. The main drawback is initial cost, and some motors are not configurable to run from a singe-phase-input inverter.



As I understand it the transformer feeding the site is single-phase, as is the 11kV overhead line. There might be more single-phase power available from the existing transformer, but to change to 3-phase requires an extra 11kV line and a new 3-phase transformer.

Thanks for that reply
So as I don't have any of these machines yet, I could buy ones that are either single phase where available, and if not get ones that can be run from inverters.
The other option I found is a digital 3 phase converter, I assume these work with an inverter type set up but not sure exactly.
Do you know about these?