I have a 3 phase 15KW generator with four wires. I want to use it as a standby generator for my house. My house uses 1 phase 220 volts on two wires (no ground as the house is quite old). I have a 3 wire transfer switch. I was wondering if I could connect the generator neutral to my mains neutral permanently and just switch the live wires. I know I should avoid this but is it really dangerous.


  1. I am going to have a problem with balancing the loads
  2. the generator is not branded i.e it made with a 1.6 litre Toyota engine (I think).

Now that its clear that I should have a solid neutral, (thanks longneck and bcworkz) is there anything wrong with implementing the following plan

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The reason for using these devices is that I already have them.

  • yes it is as it will not serve any purpose to the generator instead of that it will start providing ground to the main grid when you will start the gen
    – Deiknymi
    Jul 31 '13 at 14:51
  • 1
    @Akash your advice is wrong and dangerous.
    – longneck
    Jul 31 '13 at 18:11
  • why i am telling him not connect the generetors ground to the mains
    – Deiknymi
    Aug 1 '13 at 4:13

Why do you think you should avoid this? You should have the neutral from the generator tied to the neutral of the house.

  • 2
    A solid neutral is a common transfer switch configuration, but switched neutral switches are also available as a solid neutral can cause issues where ground fault sensing equipment (GFCI etc.) are used. With switched neutrals, the genset must have it's own equipment grounding system.
    – bcworkz
    Jul 31 '13 at 20:19
  • Even on a shared neutral it's not a bad idea to put an additional ground rod in near the generator installation. Aug 1 '13 at 18:38

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