On Friday, March 16, 2018 at 3:23:03 AM UTC-4, Oumati Asami wrote:
On 16/03/2018 12:05, Uncle Monster wrote:
On Thursday, March 15, 2018 at 9:45:19 PM UTC-5, Oumati Asami wrote:
On 16/03/2018 03:27, Uncle Monster wrote:
On Thursday, March 15, 2018 at 5:11:36 AM UTC-5, Oumati Asami wrote:
On 15/03/2018 09:13, Uncle Monster wrote:
On Wednesday, March 14, 2018 at 9:38:55 PM UTC-5, Oumati Asami wrote:
How does this circuit work?

This house has 3 phase power.

I was replacing a downlight and found it having two black, two neutral,
and one blue incoming wire.

If the light switch was on, the blue wire was energized.
If the ceiling fan was on, one of the incoming black wire was energized.

Why/how do both light and fan work when both are on?

incoming downlight
a) ================(black)------------------
b) ================(neutral)----------------
c) ----------------(blue)------------------

Knowing which country you reside in would help. ^_^

[8~{} Uncle Electric Monster

I didn't think it matters. I'm in Myanmar if this helps.


I'm guessing the normal power supplied to your electrical outlets and light fixtures is 250vac 50hz. Most folks who post here are in North America where the power supplied to regular electrical outlets and light fixtures is 120vac 60hz. Larger appliances will use 240vac. I had an instructor once tell the class,"Electrons are electrons." Meaning electrons are going to go where they want so you better guide them.^_^

[8~{} Uncle Electrical Monster

I think it is 230 v though I did not test.

I believe someone posted a link showing that it's 230vac 50hz used in your country. I found it. ^_^

http://treehouse.ofb.net/go/en/voltage/Myanmar

I imagine the wire colors are different and wire sizes are much smaller than what is used in North America. I did some modifications to some portable housing units manufactured in Australia and the wiring was stranded where the wire used here is normally solid for use in wiring run to light fixtures and electrical outlets. The question I have is, does the power supplied to your lighting circuits and electrical outlets read 230vac from hot to neutral/ground? Is there a pair of hot wires at each outlet or is there just one hot wire? ^_^

[8~{} Uncle Curious Monster


I had checked several outlets before and found them containing three
wires (LNG) and being 230 V. I did not check the particular light and
fan in question. I think they are 230 V also.

At first, I thought maybe the fan shared the neutral with the light. But
what happens when both light and fan are on?

You can have an unlimited number of devices sharing a neutral. If you have a circuit with 8 lights, there is only one neutral.