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# 3 phase wiring for lighting

Discuss 3 phase wiring for lighting in the Lighting Forum area at ElectriciansForums.net

#### Vraykinluhi

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Welcome to ElectriciansForums.net - The American Electrical Advice Forum

Hello guys,

Obviously, I'm posting this thread is to ask the experience electrical guys for help or suggestion to solve my problem.

This is the situation:

By using 3 phase line, I need to wire 10 units of lighting(which is 4,3,3) into each phases. The lighting will be devided into 2 groups. Each group of A or B will able to control of those 5 ligthing into on or off position.

I been thinking about this whole day, which is quite impossible because according to theory 3 phase must be balance.

If it is possible what component should I be using, rating, and recommendation.

Thanks for look into this. Have a nice day

#### Spoon

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Mentor
Arms
Esteemed
Welcome to the forum.
You have to balance the 3 phase the best you can. It is not always possible.

#### Pete999

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Arms
Esteemed
Welcome to the forum.
You have to balance the 3 phase the best you can. It is not always possible.
Hello guys,

Obviously, I'm posting this thread is to ask the experience electrical guys for help or suggestion to solve my problem.

This is the situation:

By using 3 phase line, I need to wire 10 units of lighting(which is 4,3,3) into each phases. The lighting will be devided into 2 groups. Each group of A or B will able to control of those 5 ligthing into on or off position.

I been thinking about this whole day, which is quite impossible because according to theory 3 phase must be balance.

If it is possible what component should I be using, rating, and recommendation.

Thanks for look into this. Have a nice day
Not the case at all Mate, many SP&N derived from a TP&N supply are unbalanced, it's the nature of the beast, whoever told you that is talking from His/Her rear end, think about how many Domestic dwellings are derived from a supply that is 400V in origin

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Mentor
Have you got a Neutral with this 3 phase supply?

#### Pete999

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Arms
Esteemed
Have you got a Neutral with this 3 phase supply?
I would hope so otherwise the question the OP is posing is mute.

D

#### Deleted member 26818

You need to use two 3 phase contactors.
Each contactor to control 5 lights spread accross the phases.
Use either one phase to control both contactors, or two phases, one for each contactor.
Using two phases would prevent total loss of lighting if one phase failed.

#### Vraykinluhi

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Have you got a Neutral with this 3 phase supply?
Yes sir, its should be because of the 240v lighting

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#### Vraykinluhi

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I would hope so otherwise the question the OP is posing is mute.
This is the question asked by my boss, I already think over it and can't get an answer, that's why I asked for you guys for help.

#### Vraykinluhi

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Th
You need to use two 3 phase contactors.
Each contactor to control 5 lights spread accross the phases.
Use either one phase to control both contactors, or two phases, one for each contactor.
Using two phases would prevent total loss of lighting if one phase failed.
That's what normally we do, but to balance the phases, it is okay to ignore one out of two phase? By the way the lighting is 240v rated and should have neutral line. The neutral line should have individual to eah feed for safety reason and maintenance

D

#### Deleted member 26818

You’re not ignoring the phases, just using one or two for control.
If there will be EM lights, I’d probably only use one phase for controlling both contactors.
How you distribute the neutral is up to you.
Obviously, using just the one for all 3 phases would be cheaper.
Of course your wiring method might necessitate separate neutrals for each phase.

#### Vraykinluhi

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Yo
You’re not ignoring the phases, just using one or two for control.
If there will be EM lights, I’d probably only use one phase for controlling both contactors.
How you distribute the neutral is up to you.
Obviously, using just the one for all 3 phases would be cheaper.
Of course your wiring method might necessitate separate neutrals for each phase.
You are right sir, since we are using 3 phase contactor. Thanks for the insight Have a nice day

Cheers

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