New 3 phase electrical service

12/07/2012 - 02:16
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After suffering through a second summer of seemingly perpetual brown/black outs, we asked Enel to upgrade our electrical service to 10KW.  When they finally came by to perform the upgrade, they determined that due to our distance from the “cabina” it would be impossible to upgrade our service without bringing in a new line from a closer source.  Long story short, we got our neighbors to agree to the new poles and wires and Enel has just finished installing the upgrade, which includes new 3 phase service being brought into our house.  We’ve received a bid for 3000 euro from our electrician to make the recommended changes to our internal electrical system, but think that may be high, so we’ve sought a second opinion.  My question for the Board is, can anyone tell me what is involved in retrofitting a newly built house (completed in 2009) to accommodate 3 phase power?  How much internal rewiring is needed to insure the safety of my family and the safe operation of the existing appliances – or is it a question of simply replacing/upgrading the panel and breakers?  We have the usual complement of appliances (dishwasher, oven, fridge, TV, washing machine and some AC/heater inverters).  I know this description doesn’t provide much detail, but I’m just trying to get a rough idea of how much pain I should expect to bear.  Thanks in advance.

We installed 3 phase 15 kw a couple of years back. Firstly you cannot run this on overhead cable , there needs to be a new cable from the electricity pole to the house buried in the ground. This stretch of cable is your responsibility, not that of the energy company. The energy company will take responsibility for connecting their end to the pole, but the trench, the cable and the connection to the fuse box is at your cost. The cable is expensive and it cost us E100 per metre (in total E1000 for the 100m stretch from the pole).  We then had to divide the fuse box into three.  How we did this was to put the pool, garage lighting and all external lighting on one set of fuses, the oven ( a monster range that takes 5kw when using both ovens) on a separate cable which we had to run  a new one from the fuse box to the oven, and then the rest of the household appliances, lighting and switches on the third.  We have never had a problem since.  However, be aware that the standing charge from the energy company to have this amount of available kw to your house is high, even though your actual electricity consumption might be moderate.

We have a 15kw 3 phase system here. The 3 phase is mainly for the heat pump. I would have thought that only the change would be the fuse box. Here there is one in the technical room direct from the Enel supply, and the feed from that goes into the house to supply the normal appliances. with another fuse box internally. Does seem to be a lot of money he is asking.

Boschetto - You say the electrician quoted for;- ".... the recommended changes to our internal electrical system, ........."   Who recommended them, and what are they? [3,000 Euros seems high, but if the changes involve splitting your house wiring into 3 separate parts, to equalise the load, it might not be too high - but get at least a second quote anyway]

It sounds like it's probably too late, but could you not perhaps just consider reducing your electrical consumption!?  I don't mean to be controversial or antagonise, but why does the answer so often seem to be to upgrade/increase consumption/more, more, more, rather than to simply reconsider consumption and needs?  Especially if new poles and lines arre involved.  We have an, albeit smallish, house on a 3kw supply with lights, TV, computers, cooker (direct plug), fridge/freezer, washing machine, electronically fired boiler or electric water heater, power tools, etc., and we have no problems with black-outs.  We used to, before we had central heating installed and when we used to try to run three 1.5kw electric fan heaters at once (doh!!!), but we soon learnt and went out and bought a couple of extra blankets! Personally, and I know many here will disagree, but I think the 3kw supply idea is excellent, particularly in a world with ever increasing utility bills and environment problems... Okay, I'll get off my soap box and go back to lurking now....!!! ;-)

Must have been a new regulation Clombardelli, as our 15kw/3phase supply was on a overhead cable to the house initially, 7 years ago. I dug out a trench, disconnected the cable from the Enel meter and put it underground, not 100 mtrs though!!, so there might have been a distance issue on your installation.

... when you install 3-phase is the rate the same as the 1-ph supply but just allocated to each phase? I've always believed that to be the case as my bills show 2 spare phases uncharged. I've been told that Enel applies regional variations but find that hard to believe.

I have three phase. My last bill from Prometeo (based in Ancona) for the period May-June 2012 (but billed in September) was E339.45 - the house was occupied 100% of the time. We have gas central heating and a gas hob (but electric cooker) - the swimming pool was not open.  The cost of 'servizi di vendita' was E100.41. the cost of 'servizi di rete' was E174.12 , Imposte erariale (whatever this is) was E24.06 and IVA of 10% E30.86.This is based on consumption of 466KW for May, and 594 Kw for June. A prior bill from 2006 (before 3 phase was installed) May and June usage was 501Kw and the cost of the KW was E88.52 and the line E30.72.  So my advice is be sure that you want to pay for the ccnvenience of having all of your electricial appliances working at the same time as the fixed costs go up substantially with 3 phase.

You must be using a lot of electricity, as my June July (16/05 to 16/07) consumption in total is  only 751Kwh. Also what power supply did you have on single phase in 2006, as prices have increased quite a lot since then. Cost was only 241.48 Our bill for 15Kw supply 04/05 - 03/07/2006 was 228.70, with a usage of 940 Kwh in the period.