How to Check the Zero Line?

According to the eletrical professional specifications,Zero line is generally blue or black wire,

you can judge whether to lay Null line according to the basis.

But the wiring in the family probably did not press normative wiring,

cannot undertake distinguishing from color,suggest you ask the opinion from professional personage.

For example:

The switch need null line.

The switch support tuya app

loudspeaker support Tmall / Amazon Alexa /Google Home

Switch speaker support 2.4g signals from routers,not 5G.

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