currently 2 phases in venue unable to upgrade to 3 phases

[A.foster]

Hi looking for some advice I am about to start a commercial job in a rural area the venue is being totally renovated it is a 30 bed hotel which is being extended will have 2 bars large function room a large commercial kitchen and a spectate motel in the future. The venue is only supplied on 2 phases only To upgrade to 3 phases they local sub station will have to be upgraded and a new line dug to venue. The custerner Is wanting to install air con units which will take up a lot of demand I have recommended to not go with air con and gas appliences in the kitchen. Has anybody come across this problem before? And does anyone have any possible solutions? Thanks

 

[Pete999]

Tell your client to apply to the energy supplier to have an adequate 3 phase supply installed. The supply characteristics should have been discussed at the planning stage of a project like this not left until the last minute. IMO

 

[telectrix]

what he said ^^^^.

 

[Darkwood]

As above, it would seem like this whole project could anchor on the supply available and it should never have left the table until a solution had been found, I suspect a DNO TX plus cabling could be anything from 20k - 100k situe dependent and they may request part of the land to house the TX and all rights to access (again situations vary).

If your customer seems to be turning a deaf ear then you need to arrange a meeting with the building contractor and all parties affected, this could mean some large contracts are stopped on the site which too could have legal fallback.

The customer 'if unaware' of this at the planning stage will be perfectly within their rights to demand some explanation and possible compensation if the project is delayed or major costings and/or changes are made to the contract.

 

[malcolmsanford]

I would also check and see if it is in fact single phase 3 wire. Often in rural areas you find this on older installations.

It may very well be 2 phases, but unusual for a DNO to unbalance things like that

 

[benji]

Seen this at Redworth Hall and phase converters were fitted to lift supplies & air handling units

 

[A.foster]

Seen this at Redworth Hall and phase converters were fitted to lift supplies & air handling units

I have been looking into phase converters and have been told not possible do you have any idea were these were located from? Cheers

 

[Barry White]

I would also check and see if it is in fact single phase 3 wire. Often in rural areas you find this on older installations.

It may very well be 2 phases, but unusual for a DNO to unbalance things like that

Agree with above suspect it will be split phase (3 wire single phase) Its easy to check as the sum of the 2 phases to neutral will equal the voltage across the lines (phases) ie 230v +230v = 460v if it was 2 poly phases it would of course be 400v and 230 between line and neutral.
Voltages shown for comparison actual will be more.

The convertors benji mentions are an option you just need to find the size of the supply and check its adequate.

 

[bomjac]

Specialist transformers may be a solution - something like a Scott-T which can convert the 2 phase to 3 phase. If your existing 2 phase supply is sufficient then you should be able to get VSD driven AC units which will run quite happily with a 2 phase supply to them, yet provide the 3ph required for the compressors and fans. The AC will be more expensive than conventional, but there will in the longer term be savings on the compressors and fans due tou this.

If the loading on the supply is going to increase significantly then that needs to be cleared with the DNO also, and to verify that the existing cabling us adequate.

 

[Marvo]

Agree with above suspect it will be split phase (3 wire single phase) Its easy to check as the sum of the 2 phases to neutral will equal the voltage across the lines (phases) ie 230v +230v = 460v if it was 2 poly phases it would of course be 400v and 230 between line and neutral.
Voltages shown for comparison actual will be more.

This was my first thought when I saw the word 'rural' and 'two phases' in the OP. Before going any further check the voltage between the two phases, if it's 480V this will add to your design issues.

 

[mrloy99]

what sizes are the main fuses and cable?100 amp mightnt do. you could maybe get a larger cable put in,albeit 2 phase without the cost of changing the substation......or get some eco **** put in..wind mill solar panels,ground source heat pump....wood chip generator