A lot of homes have a 3-phase electric connection. Each of the phases has some appliances connected to it. That implies power consumption in any moment on each phase is different, so we have an unbalanced or non-symmetric load.

A strongly unbalanced load is not desired because:

  • (3-phase) circuit breakers can trip because of the one overloaded phase. Even if the total load if far below the circuit breaker's designed maximum. If this happens with the main connection circuit breaker, the whole house is blacked out.
  • It causes higher losses and lowers the energy transmission efficiency.
  • The power supplier company can penalize the consumer for it.

Are there any affordable means of balancing the power consumption of 3-phase home connection? Commercial solutions are preferred, but DIY is accepted too.

Reconnecting the appliances is an option to improve the power consumption balance to some extent. But it's nonsense to use a vacuum cleaner only because the washing machine is on. The 3-phase consumption will always be varying, so at least improving the balance would suffice.

A phase-shifting transformer helps this situation in transmission networks but it is a utility grade solution.

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    The only practical measure I know of is to thoughtfully layout the circuits on the distribution panel so large coincident loads are on different legs and random loads such as lighting are well distributed amongst the legs.
    – bcworkz
    Commented Feb 4, 2013 at 23:27
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    What country is this where 3-phase being used in the home? Split phase tends to be the common household power with 3-phase being used for industrial and agriculture in my experience. Commented Feb 5, 2013 at 3:42
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    I'm located in Slovakia, EU. Most of the homes are 3-phase connected here. Maybe even most of Europe is so, but I'm not sure.
    – Peter Ivan
    Commented Feb 5, 2013 at 7:54
  • In the U.S. homes typically have split-phase power. With three phase going to buildings that need more power. Commented Feb 5, 2013 at 15:22
  • Here (Italy) I can confirm: almost all buildings get 3 phase but homes usually are only connected between a single phase and the neutral, but 3 phase connection is available at no extra cost. For your specific issue, I think you should better plan your breaker box (distributing loads better across phases).
    – DDS
    Commented Apr 17, 2018 at 23:13

1 Answer 1


Instead of rerouting load, intelligently adding home-made power production is the future. Disconnection of something with a cpu in it (everything beside a hot iron)is a bad idea.

In Europe, where even the smallest villages have 3-phase connection to every home, solar panels with LiIon buffer battery are hot. A 100W panel is ~300€ all inclusive. The DIY part would be the intelligently giving the selfmade power to the most loaded phase and only when it's assymetriccaly.

A friend did that with a small river generator in order to save penalty from the power supply company.

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    Do you have any references/documentation on how to make such the DYI part?
    – Peter Ivan
    Commented Feb 22, 2013 at 7:44

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