On 15/03/2018 18:27, Dean Hoffman wrote:
On 3/15/18 6:27 AM, trader_4 wrote:
On Thursday, March 15, 2018 at 6:09:18 AM UTC-4, Oumati Asami wrote:
On 15/03/2018 09:38, trader_4 wrote:
On Wednesday, March 14, 2018 at 10:38:55 PM UTC-4, 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?

Â*Â*Â*Â*Â*Â*Â*Â* incomingÂ*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* downlight
a) ================(black)------------------
b) ================(GROUND)----------------
c) ----------------(blue)------------------

IDK why a house anywhere would have 3 phase power. But there is a
wire for the light, a wire for the fan, two neutrals, so what's the
issue?

Sorry, the diagram was wrong. I mistakenly labelled ground as neutral.
It is now corrected.

When both fan and light are on, both the blue and black wires are
energized.

So, again, you have a hot for the light, a hot for the fan and a
neutral. What's the issue?

Â*Â*Â*Â*Â* Is the equipment ground being used as the neutral?Â* It must be
tied to the neutral
upstream somewhere.Â*Â*Â* That's illegal at least in my world.

How do I test if ground is used as neutral?

The main breaker is a GFIC. I have experienced unexplained tripping.
Would that have anything to do with ground being used as neutral?