electric nightmare

[feldri]

Is it possible to run ordinary diy tools off a three phase electric supply or do i need a transformer of some kind. I'm hoping to move into a small workshop unit soon with my sanders, thicknesser etc; but they all run off 240v and someone has told me that three phase is 400v. please help

 

[BR]

feldri, this is not a problem and no transformer is required. The voltage between one phase and neutral is 230V. However dealing with the electrical system in this workshop is not a DIY job and you will require an electrician

 

[breezer]

feldri, this is not a problem and no transformer is required. The voltage between one phase and earth is 230V. However dealing with the electrical system in this workshop is not a DIY job and you will require an electrician

is it me or does it read that you should use a phase and earth?(which you CAN NOT DO)

feldri, i doubt it only has 3 phase, since if it did the lights won't work, as lights are single phase, it may onlty have 3 phase sockets, why not get an electrcian in to check it for you

 

[BR]

this should read neutral, so as to be absolutely clear. The point i was trying to make is that a three-phase system is perfectly capable of supplying single-phase apparatus at 230v.

Above post has been edited.

 

[Big_Spark]

Is it possible to run ordinary diy tools off a three phase electric supply or do i need a transformer of some kind. I'm hoping to move into a small workshop unit soon with my sanders, thicknesser etc; but they all run off 240v and someone has told me that three phase is 400v. please help

Phone an electrician, your 230V kit will run off a 400V 3 phase supply, but you need to know what your doing to do it correctly.

As Breezer and BR have noted, 400V 3phase is NOT something for your DIYer to get involved in.

 

[AdamW]

Isn't it ill-advised to run equipment off one phase of a 3-phase supply?

I know they used to do it that way but you can run into problems with unbalanced loads on the supply. OK so if you add it all up the power station sees an even load as 1/3 of people will end up using each phase, but surely this is bad practice.

 

[Big_Spark]

Isn't it ill-advised to run equipment off one phase of a 3-phase supply?

I know they used to do it that way but you can run into problems with unbalanced loads on the supply. OK so if you add it all up the power station sees an even load as 1/3 of people will end up using each phase, but surely this is bad practice.

Adam, I doubt we are talking about one machine, another reason for calling a spark as they have the knowledge to ensure that the loading is as balanced across the three phases as is possible in that installation.

It is a simple matter to reasonably balance a 3 phase supply if you know what your doing.

 

[Kimba]

Isn't it ill-advised to run equipment off one phase of a 3-phase supply?

I know they used to do it that way but you can run into problems with unbalanced loads on the supply. OK so if you add it all up the power station sees an even load as 1/3 of people will end up using each phase, but surely this is bad practice.

Nearly all houses are one single phases. A three phase supply usually comes to the end of the street, and then groups of house are on each phase, to crudely balance the load. To cause problems with an unbalanced load, you need serious differences between loads on the phases, at which point the return (or "neutral") will probably be carrying a substancial current.

When I worked in a theatre we rarely had to worry about balancing, and we would be pulling 100's of Amps more on one phase than another. Sometimes it just can't be helped.

 

[Big_Spark]

Nearly all houses are one single phases. A three phase supply usually comes to the end of the street, and then groups of house are on each phase, to crudely balance the load. To cause problems with an unbalanced load, you need serious differences between loads on the phases, at which point the return (or "neutral") will probably be carrying a substancial current.

When I worked in a theatre we rarely had to worry about balancing, and we would be pulling 100's of Amps more on one phase than another. Sometimes it just can't be helped.

Nice crude description of the supply in the street, but it'll suffice

Regarding your fun in the Theatre, that is actually ILLEGAL under the Electricity Supply Regulation Act 1989 (It did have earlier versions)

Any consumer that willfully, or knowingly, causes an inbalance in the supply is liable to summary disconnection of service and prosecution, and creating an inbalance of more that 25% per phase falls into the KNowlingly and willingly bracket!!

 

[Kimba]

Who said it was more than 25% though?

There was an Electricy Supply Act 1989 (for suppliers not consumers)
and a Electricy at Work Refualtions 1989, but can't find the one you refer to, although I am sure you are right, I would like to read it if you know where I might find it?

Well I could do a far more exact description, but I always think it is best to match the description to the requirement

 

[ban-all-sheds]

Any consumer that willfully, or knowingly, causes an inbalance in the supply is liable to summary disconnection of service and prosecution, and creating an inbalance of more that 25% per phase falls into the KNowlingly and willingly bracket!!

Interesting. My employer sells a product which uses 2 phases of a 3-phase supply....

 

[Big_Spark]

Who said it was more than 25% though?

There was an Electricy Supply Act 1989 (for suppliers not consumers)
and a Electricy at Work Refualtions 1989, but can't find the one you refer to, although I am sure you are right, I would like to read it if you know where I might find it?

Well I could do a far more exact description, but I always think it is best to match the description to the requirement

Unless you have a HUGE supply, I think it is safe to say you broke the 25% rule .

You are correct, there is a Electricity Supply Act 1989, but there is also the Electricity Supply Regulations Act 1968/1974/1976/1984/1989

Many beleive that both these Acts only deal with suppliers of electricity, but in fact both impart a legal responsibility to the consumer to manage their supply adequately. This is where the 25% rule arises.

In the old days of the Government bodies, this used to be enforced, but not so today..more is the pity.

I'll try to find an online link to the act, I only have a hard copy..