3 Phase dedicated mains supply

In order to accommodate the requirements of our ever burgeoning eco-friendy electrics (solar, heat pump, batteries, EVs), we Asgaardians are considering 3 phase mains. Current budget does not allow for dedicated substation, however.

  1. Have you got a 3 phase supply?

  2. Does the Naim system have preferential treatment on either a specially curated, or completely dedicated, phase?!

  3. Did you notice any discernible improvement in SQ, hum, etc?

Isn’t 3 phase 415V?

Not according to my house :grimacing:

Yes or thereabouts.

Single phase 220 ish is one of those phases.

In a ‘normal’ 3 phase house system those 3 phases are split in such a way that the house load is balanced across those three phases. Putting just your stereo system in one phase is likely to result in a load imbalance and trip out occasionally one or the other of the phases. Get an electrician to look at the load and split it according to usage. If you have any 3 phase appliances, in a domestic setting typically a large water heater, then that needs its own circuit.


3 phase in my house in France is an absolute nightmare- unless you have the appliances balanced the load will trip. Then you end up like the Wichita lineman looking for another overload.

I gues it’s alright if you are running an industrial factory but in a home…

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Current (!) usage is close to maximum for single phase. Advent of second EV could push us over.

Andy, I take the point about balance, in which case do you select what is and is not on the system phase?

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No not as such but it is interesting, in the UK the system like a true Naim system hums away from time to time.

But in France, I’ve never had a single hum from my Naim system.

The problem is an overload in the kitchen when the kettle, oven and heater is on will trip the whole house.

Hmm, heavy load! I had a similar problem when we put in a dedicated spur for the system. Every time I switched on the ‘geddon, the 16A dedicated system fuse tripped. In the end we replaced the fuse with a 32A one which cou;d cope with the ‘geddon’s start up surge for power.

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See if you can get a local electrician to re balance the loads across the day.

In the UK the single phase supply is a misnomer. The supply is three phase, but the electricity company splits it in the street. Imagine houses 1-10 get one phase, houses 11-20 get the second phase, houses 21 to 30 get phase three, and repeat.


Yes, I know I need to get the rebalancing done - has been on my list of things to do for the last 5 years. I threw out three kettles thinking they were duff before I realised what was going on.

But as you know in the UK you can switch pretty much every thing on in the house and the supply happily plays ball.

Yep. When we first moved here we would have random trips, usually at some inconvenient time. I replaced the board and rebalanced according to usage and time of day. No problems since.
We needed a new board anyway so rebalancing was relatively straightforward.
Re the UK, the load across multiple outlet points means that a single home is unlikely to trip as it is a small percentage of total load across all outlets.


Unless it’s an Armageddon…

3 phase voltage is measured between any 2 of the 3 phases.
Single phase is the voltage measured from any 1 of the 3 phases to neutral or earth.
In UK the 3 phase might be at 415v it varies depending on local supply, but officially it’s harmonised all over Europe to 400v with single phase at 230v.


Sage advice as always Mike. Our issue here is that future demand will outstrip single phase supply.

The UK has adopted the eu standard at 400v/230v but historically it has been and still is in many places 415v/240v.

Out of curiosity, how do you balance? Do you have three meters that you have to watch to spot big variances? Or an app? Also what sort of load difference would cause a trip? Would that therefore trip all three phases?

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Good questions!

You have three feeds. Make a table of each electrical item that draws power and the wattage drawn at any given time. Split the table into three equal wattages. Connect each set of appliances to any one phase.

Eg 5 x 2 kw heaters on one phase and 10x1kw kettle points on another, and one 10kw bitcoin computer room on another. Ridiculous examples but you get the idea. Time of use is the main factor. If you have your large water heater on between 2 and 4 pm on one phase its probably best to put your room heaters that are on at the same time on another phase. On the other hand if you have the water heater on between 2 and 4 am, it could be on the same phase as your electric room heaters that are only on between 2 and 4 pm.
It’s a compromise dependent on your usage.

Edit. What difference causes a trip? I haven’t got any idea but its usually associated with an overload on one phase. All 3 will trip.

Wow, so manual. I would have thought a Watt or Amp meter on each might serve a good use here