3 phase power at home?
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Discussion

jason61c

Original Poster:

5,978 posts

196 months

Thursday 23rd July 2020
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Has anyone upgraded to 3 phase power at home? With a car on order, a lathe/mill/car ramp that are all ran off a rotary phase converter, it could make total sense for me.

If so, what did you pay? can you still get the same deals as 'normal' supplies?

robbieduncan

1,993 posts

258 months

Friday 24th July 2020
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Mroad

829 posts

237 months

Friday 24th July 2020
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Price will depend on individual situations as there's obviously huge installation cost difference between someone next door to a substation/decent supply access than to someone in a rural location on the end of a supply leg that might need upgrading to cope.
For example it cost over £11k to install 3 phase to my fathers builders yard due to needing to run a mile of underground cable from a supply point and installing a pole transformer and that was just to the trasnformer (and this was 20 years ago). It was reduced to virtually nothing due to wayleave for letting them install the pole on his land and they then could provide supply to other local businesses and shore up the local weak domestic supply around his business so was to their advantage.


jason61c

Original Poster:

5,978 posts

196 months

Friday 24th July 2020
quotequote all
I've started a thread in the homes section.

If its under £2k, i'll go for it, mainly just to get rid of my noisy rotary phase converter and allow a newer cnc mill to work without worry.

robbieduncan

1,993 posts

258 months

Friday 24th July 2020
quotequote all
jason61c said:
I've started a thread in the homes section.

If its under £2k, i'll go for it, mainly just to get rid of my noisy rotary phase converter and allow a newer cnc mill to work without worry.
Based on what UK Power Networks say it will cost I'd say it's not likely to be under 2k. Maybe under 3k: https://www.ukpowernetworks.co.uk/electricity/upgr...

jjwilde

1,904 posts

118 months

Friday 24th July 2020
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Cost me <£900 all in. All depends on how close the cables are to you.

If I'd done all the work myself it would have cost <£300 (just the standard connection fee).

FlossyThePig

4,138 posts

265 months

Saturday 25th July 2020
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My house was owned by the MD of Eastern Electricity in the mid 50s to mid 60s. Why else would a country lane have buried supply cables rather than hanging off a series of poles? Thinking "future proofing" before the term was invented he had a 3 phase supply installed. We still only use one of the phases but I do have the option without installation costs.

granada203028

1,500 posts

219 months

Saturday 25th July 2020
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You are very lucky and I'm very envious.

So you haven't had the curiously to have a 3 phase socket installed so you can run a 3 phase motor and enjoy reversing it just by swapping two phase?

No crap split phase thing with capacitors frown

OldGermanHeaps

4,892 posts

200 months

Saturday 25th July 2020
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Is the standing charge and cost per kwh not much higher too? one of my customers frequently complains he cant get a decent tarrif at home because he needs 3 phase.
Have you looked at solid state variable frequency drives?
I installed one for a customer to have 3 phase ramps at home and the soft start is easy on the elecrical system, never dims the lights like the single phase ramps he had before did.

jason61c

Original Poster:

5,978 posts

196 months

Saturday 25th July 2020
quotequote all
Vfds are rubbish for proper motors, they can over heat and you can’t add multiple motors. Not to mention on cnc stuff they can’t run low voltage control stuff. Also can’t have multiple things(mill and ramp etc) at once.


jjwilde

1,904 posts

118 months

Saturday 25th July 2020
quotequote all
OldGermanHeaps said:
Is the standing charge and cost per kwh not much higher too? one of my customers frequently complains he cant get a decent tarrif at home because he needs 3 phase.
No, they don't even ask about it.

granada203028

1,500 posts

219 months

Monday 27th July 2020
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jason61c said:
Vfds are rubbish for proper motors, they can over heat and you can’t add multiple motors. Not to mention on cnc stuff they can’t run low voltage control stuff. Also can’t have multiple things(mill and ramp etc) at once.
Yes single phase input VFDs don't seem to go much bigger than 2.2KVA and don't seem to be required to have power factor corrected input like switched mode power supplies.

They work pretty well one per motor though. I have one on a pillar drill, would not be without it. Not as reliable as proper 3 phase. The drill is on its 2nd drive and both this and the previous one have had to be repaired once. It currently trips the house RCD so is on an isolating transformer. As I say jealous of proper 3 phase.

jason61c

Original Poster:

5,978 posts

196 months

Monday 27th July 2020
quotequote all
granada203028 said:
Yes single phase input VFDs don't seem to go much bigger than 2.2KVA and don't seem to be required to have power factor corrected input like switched mode power supplies.

They work pretty well one per motor though. I have one on a pillar drill, would not be without it. Not as reliable as proper 3 phase. The drill is on its 2nd drive and both this and the previous one have had to be repaired once. It currently trips the house RCD so is on an isolating transformer. As I say jealous of proper 3 phase.
Motors running on VFD's tend to get a lot hotter also. lets see where it gets to, really hoping under £2k...... No idea where the local substation is and as its all overhead.

jason61c

Original Poster:

5,978 posts

196 months

Thursday 30th July 2020
quotequote all
So- mini update. The pole next to my drive has 3 phase, the 10mm cable to the garage can supply enough to run my house. So hopefully if the DNO costs are sensible for the connections, I’ll have a 3 phase supply and meter in the garage and run the house on a single phase using the existing cable to the garage.

Just patiently waiting on the dno costs now.

jason61c

Original Poster:

5,978 posts

196 months

Friday 21st August 2020
quotequote all
So costs are in from WPD..........

£1100.24 inc vat.

I've got to add on cable to feed the house from new location, £200 ish.

Sparky for a day £200ish

£200 for bits i've not yet thought about.

so, £1700 all in.

Result.

granada203028

1,500 posts

219 months

Friday 21st August 2020
quotequote all
Sounds good to me but I'm a 3 phase enthusiast.

I assume you are going for it then. Please keep us posted how the installation goes.


jason61c

Original Poster:

5,978 posts

196 months

Friday 21st August 2020
quotequote all
granada203028 said:
Sounds good to me but I'm a 3 phase enthusiast.

I assume you are going for it then. Please keep us posted how the installation goes.
Totally going for it. I'll get around £1k for my rotary phase converter to offset.

agent006

12,058 posts

286 months

Saturday 22nd August 2020
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jason61c said:
So costs are in from WPD..........

£1100.24 inc vat.

I've got to add on cable to feed the house from new location, £200 ish.

Sparky for a day £200ish

£200 for bits i've not yet thought about.

so, £1700 all in.

Result.
That's pretty reasonable given the same WPD charged us nearly £1500 to move our single phase meter from indoors to outdoors on the other side of exactly the same bit of wall.

anonymous-user

76 months

Saturday 22nd August 2020
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In the old days you could take the other phases from your neighbours. A chap near my grandparents built a workshop at home after the war and in return for a cobbled up three phase supply courtesy of next door both sides he paid for their electricity.