American 208V 3 Phase to Ireland spec

Swampy

Hi All,

Can you please advice on how easy, difficult or costly it would be to have an American 208 3 Phase made to work in Ireland. Would I need a costly transformer?

Thanks.

brightspark

More information is required.


What is the kVA needed?

What is the load? Motor? Heaters? Control circuits?

Is it frequency dependant?

Cost and difficulty will depend on your requirements.

Swampy

brightspark wrote: »

More information is required.


What is the kVA needed?

What is the load? Motor? Heaters? Control circuits?

Is it frequency dependant?

Cost and difficulty will depend on your requirements.

This is a link to the manual, http://www.groenkettles.com/wp-content/download/Groen%20TDB%20Kettle%20Manual.pdf
Its for the TDB 7 20 quart.

There is some electrical information on pages 5 through 8 if you would not mind having a look.

Many thanks.

brightspark

Are you buying it new?

If you get it with the 240V elements, the wiring should be easily modified (by someone competent) to suit our supply without a transformer.

There is a small but unlikely possibility of needing to change the controls transformer, but the 240V connection should be OK.


Do you have 3 phase power? The unit is about 8 kVA, so you will need an adequate supply. On single phase it will draw about 35 Amps!

Swampy

brightspark wrote: »

Are you buying it new?

If you get it with the 240V elements, the wiring should be easily modified (by someone competent) to suit our supply without a transformer.

There is a small but unlikely possibility of needing to change the controls transformer, but the 240V connection should be OK.


Do you have 3 phase power? The unit is about 8 kVA, so you will need an adequate supply. On single phase it will draw about 35 Amps!

Hi, No I would be buying it used. Its a 208V. Would that be a big issue? Yes I have 3 Phase power.

I might be able to get a single phase version at 208V if thats any good.

brightspark

It looks like the elements on the 208V model are rated for 240V, (rated at 8.4kW @ 240V and 6.3kW @ 208V). So it should be ok.

Converting the wiring isn't a DIY job though, but an 8kW transformer wouldn't be cheap either.

Swampy

brightspark wrote: »

It looks like the elements on the 208V model are rated for 240V, (rated at 8.4kW @ 240V and 6.3kW @ 208V). So it should be ok.

Converting the wiring isn't a DIY job though, but an 8kW transformer wouldn't be cheap either.

So would 3 phase work ok? Would it work on 3 phase on a standard supply 230v?

brightspark

Swampy wrote: »

So would 3 phase work ok? Would it work on 3 phase on a standard supply 230v?

Yes, but it would need to be rewired to connect the elements in a STAR instead of DELTA arrangement.

Also it will need a neutral connection in addition to the three phases.

From the information provided the elements are about 6.8 ohms.

@ 208V ~ 6.3kW
@ 240V ~ 8.4kW

So on our three phase supply it will run at about 7.7kW.

The transformer will need a feed from one phase and the neutral instead of the existing supply.

One end of each element will be connected to the neutral.

From a safety point of view the contactors would probably need to be wired in series.

I personally would add suitable fuses or circuit breakers to the element supply and also the supply to the transformer.

Get your own electrician to look at the drawing on page 23, to see what he thinks.

Swampy

brightspark wrote: »

Yes, but it would need to be rewired to connect the elements in a STAR instead of DELTA arrangement.

Also it will need a neutral connection in addition to the three phases.

From the information provided the elements are about 6.8 ohms.

@ 208V ~ 6.3kW
@ 240V ~ 8.4kW

So on our three phase supply it will run at about 7.7kW.

The transformer will need a feed from one phase and the neutral instead of the existing supply.

One end of each element will be connected to the neutral.

From a safety point of view the contactors would probably need to be wired in series.

I personally would add suitable fuses or circuit breakers to the element supply and also the supply to the transformer.

Get your own electrician to look at the drawing on page 23, to see what he thinks.

Thats great. Thanks for your help.

Bruthal

Good advice from brightdpark there.

I would add that the ends of the elements wont really need to be connected to neutral once they are always either fully on together, or fully off. With 3 element ends connected together, the other ends would have a phase each via the 2 contactors in series to maintain the original design control setup.

Neutral just needed for the control transformer.

The entire thing could be run from single phase as well, although 3 phase is obviously preferable.

It can be run from Irish power supply, without any transformer.

brightspark

Bruthal wrote: »

Good advice from brightdpark there.

I would add that the ends of the elements wont really need to be connected to neutral once they are always either fully on together, or fully off.

Thanks Bruthal,

But if the star point isn't connected to the neutral what will happen to the other two elements in the event of one element or it's supply cable developing a short?
I know it's more likely to go open circuit, but a short is still possible depending on the element and wiring design.

Connecting the neutral to the star point will also mean that if one element fails open circuit the unit will still heat at about 2/3rd power, without it it would be lower.

Bruthal

brightspark wrote: »

Thanks Bruthal,

But if the star point isn't connected to the neutral what will happen to the other two elements in the event of one element or it's supply cable developing a short?
I know it's more likely to go open circuit, but a short is still possible depending on the element and wiring design.

Connecting the neutral to the star point will also mean that if one element fails open circuit the unit will still heat at about 2/3rd power, without it it would be lower.

Some of my thoughts on it at the moment anyway,

If an element develops a fault and the unit continues to operate without tripping, it would be best to have it fixed, rather than continue using the unit with a faulty, and possibly split open element. It might be more likely to be noticed and fixed, when operating at a much lower output.

If the supply cable to an element develops a short, it would be hoped that a breaker would trip, probably a 3 phase one, disconnecting the entire unit anyway.

Its an interesting point anyway.

brightspark

Bruthal wrote: »

Some of my thoughts on it at the moment anyway,

If an element develops a fault and the unit continues to operate without tripping, it would be best to have it fixed, rather than continue using the unit with a faulty, and possibly split open element. It might be more likely to be noticed and fixed, when operating at a much lower output.

If the supply cable to an element develops a short, it would be hoped that a breaker would trip, probably a 3 phase one, disconnecting the entire unit anyway.

Its an interesting point anyway.

Probably an indication of the age of equipment I have worked on that most units used fuses rather than linked circuit breakers!

Bruthal

brightspark wrote: »

Probably an indication of the age of equipment I have worked on that most units used fuses rather than linked circuit breakers!

Yea I worked on commercial restaurant ovens for a while in early 90s myself. And microwaves. I have a lasting memory of microwaves, especially one that I had a very brief connection to its 2.5kv transformer:)

It would be perfectly fine to run neutral to the elements star in the setup here of course.