3 Phase suppy required?

[simonspark66]

Im working on a 15 bedroom nursing home, all on suite. Also has commercial laundry and kitchen, dayroom,TV room etc. I have calculated the total load to be 260 Amps, not allowing for diversity.
Currently has single phase supply with a 60A fuse.

 

[Marvo]

Why is there such a big difference between the supply they are running on now and your calculated total load? In theory it should be impossible for them to be operating at the moment...

 

[simonspark66]

The place has not opened for business yet. Is due to in a month or so

 

[londonlec]

The place has not opened for business yet. Is due to in a month or so

Good luck!! Why on earth did they put a 60 in?

 

[simonspark66]

It was a farmhouse that has been converted. I have told the owner that 3 phase is required but he will not listen to me

 

[Marvo]

The place has not opened for business yet. Is due to in a month or so

Ahh, that makes more sense. If he wants to disagree that's his prerogative if he's writing the cheques. Just put you recommendations in writing or an email and get him to sign or reply to it, that way when the kak hits the fan you're covered. The way I look at it is if the supply main MCB is tripping, that's not an electrical fault, it's supposed to do that so it's a user fault so you're covered.

 

[simonspark66]

Yeah I let him know so I'm not getting blamed when the fuse blows. I just cannot see the place being able to operate until the supply is upgraded

 

[malcolmsanford]

Simon do you know the contrators invloved with this job, and was it a conversion, or a refit.

 

[simonspark66]

All I know is that the project has been ongoing for a number of years and has had at least 2 electricians previous to me working on it. It has been tested but needs a lot of snagging which is what I'm doing. The building used to be a modest sized farmhouse which has been converted

 

[malcolmsanford]

What is the kitchen gas or electric, and same with laundry gas and electric. These are the obvious power loads.

If the kitchen and CH is gas, and for a 15 bed house there is what perhaps 3 or 4 9 kg machines and a tumble dryer, the sheets and towels put out to contract. You could be quite suprised how far a BS 1361 60amp fuse will take you.

But in all fairness I would have thought it would have been 3 phase.

 

[simonspark66]

The Cooker is gas and I have convinced the owner to put a gas, not leccy, deep fryer in. Tumble dryers are also gas. Has 2 commercial washing machines. All hot water and heating is also gas. I agree with you those 1361 fuses take a lot to blow. I have told the owner not to operate the laundry when the kitchen is open and well..who knows?! Unfortunately by the time there are a few kettles around and I keep getting told to add more circuits (4 DB's in the place) I'm sure the 1361 will blow

 

[ezzzekiel]

guaranteed to show its ugly head at a later date, allowing for diversity you could prob be down to just over 100a and the 60a 1361 would prob handle this untill the building is in ful use so prob in a few months some legal representative will b on the phone shouting the odds as you didnt design it correctly...

get something in writing!!

 

[simonspark66]

Yep think I will be getting something in writing off the owner. The repercussions of the fuse blowing when there are elderly residents is very worrying and I'm sure the local authorities would get involved it it happened more than once.

 

[malcolmsanford]

This is why I asked who did the contract and therefore the original design, it sounds to me that this could be the owners having a sharp intake of breath when the original designer asked for a 3 phase supply and they were given the costings by the network distributor. Becasue we all no landlords/business people/owners just love spending money on a properly design electrical installation