Should I have 3 phase supplied to my house?

[Clive FosterParticipant @clivefoster55965]

Hafta say I spent a lot more than that getting the supply in, cable laid to the workshop and everything ready to hook up. Then couldn't find anyone willing to do the actual connection and commissioning work for me. Gave up after 4 "yeah I can do that" followed by no shows and/or silly quotes just to lay wires in the workshop leaving me to arrange all the safety and commissioning details.

Utility backroom folk were quite helpful as to what procedures needed to be followed but clearly proper signing off would be needed and that i could not find.

So if planning such work I'd say first catch your electrician and verify that he / she is actually up for the job.

Dunno what happens with new domestic three phase connections in these solar panel, smart meter and supplier switching days.

At least I got the single phase incomer modernised and made relaible. I knew the old one was um "iffy" around end of garden / road area but whata ctually came up was something of a shock to boith me and the electricity folk. Usual four guys on the job. Two to work, two to watch plus an inspector calling at second tea break!

Clive

[Former MemberParticipant @formermember19781]

[This posting has been removed]

[not done it yetParticipant @notdoneityet]

Posted by choochoo_baloo on 11/06/2019 16:23:35

I would normally ignore this sort of remark, but you've hacked me off by doing it twice in this thread.

What we don't need is your flippant remarks. Aren't we lucky that there are such clever people like you about who know all of these things.

As a newcomer, I remain grateful for the advice I continue to get from 90% of contributors on this site.

Edited By choochoo_baloo on 11/06/2019 16:23:54

Perhaps my first post that ‘hacked you off’ was the suggestion to find out the cost yourself, which you have subsequently managed to do? Exactly the ‘advice’ you needed? Lots of members of the forum don’t ask many questions because a little research often supplies the answer to their queries.

How much better it might have been to post a thread outlining the different costs just to demonstrate how much cheaper the VFD/converter route was?

Two phone calls (or emails) – one to Transwave and one to your power supplier – would clearly have saved a great deal of wasted effort.

[Clive FosterParticipant @clivefoster55965]

If my experience is anything to go by getting a sensible all inclusive quote for 3 phase being laid on isn't easy. And having been quoted how do you know if the figures you got are reasonably sensible or not without comparison to what other folks got it for.

Really when initially thinking about something like that well outside your experience its good idea to ask around and find out what folk actually paid when all was done and dusted.

Certainly in my case there were big differences in what I got and what it ended up costing between initial enquires and firming up for the work. Even then the bill was perhaps 20 % more. Fair few hidden extras I found. The original basically covered opening the "road" and making standard joint and laying the cable up my trench in the drive. Plus trenching the "road', plus signing, plus covers, plus remedial works on the main cable, plus connection after the cables were in. I had to pay for the cabling too of course. Bit annoying to find that I had to pay to have the original incomer connection removed and re-jointed after it was condemned as dangerous. I got off lightly on the road side of things as the electricity folk accepted that the lane I live in was technically what I was told is called a "Public Street" essentially owned by nobody yet freely accessible by folk at their own risk. So not even considered a footpath so no permissions needed for work outside my frontage.

I lay serious odds that an experienced contractor would have got things much cheaper.

Of course the ever falling price of VFD boxes has made the whole thing something of a white elephant. Although some of the prices on HASS TM1 and the like relative to what can be got for a good Bridgeport with all the trimmings are attractive!

Clive

[Phil WhitleyParticipant @philwhitley94135]

Three phase is very convenient, and there are power loss drawbacks with inverters, and it means that your three phase machinery is no longer plug and play, but I think £3100+ vat is very toppy when you have done the trenching on your property, and all they have to do is a joint and cable, and then fit meters. It would be a day job for two men, possibly three, but there is usually a fee to pay for opening a pavement too. In the days of the nationalised electricity boards, they had an incentive, as you would use more power when it was made available, but now the utilitys are seperate, and the cable installs are done by a differnt company to the one selling the power, the incentive is gone. Some thing did work better as nationalised industries!

[Bear G 1Participant @bearg1]

100% get 3 phase at home. Walk outside and see if there is a transformer on a pole (assuming the cable is above ground that is). The closer this is the better it is for you.

Having 3 phase opens up a world of cheap machines because people fear them. No, I'm not joking. I have seen people look at pillar drills, etc and reject them because they're 3 phase!

Some cautionary notes on static converters; they can kill motors very quickly if the settings are wrong and also cause the motor to run hotter. I was with a mate who was running his lathe off one of these; when he shut off the main motor the pitch of the suds motor changed because the entire current was now going straight into this. It would've destroyed it if he hadn't switched it off a bit quick.

Rotary converters are the best all round solution and the closest to a pure 3 phase output but unlike a static they out send out the demanded power output thus not causing any damage to secondary motors like suds pumps. You can also run your entire workshop off just one.

Inverters…having variable speed is great as long as you remember that the motor was designed to run at the rated speed with the fan providing the cooling. Run it slower and you lose some of this along with some of the torque. Run it too slow for a long time and you'll cook the motor.

Bear

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