Flameport's advice is correct.
Winston's "advice" is wrong
Obviously it makes sense to install one for convenience.
Convenience or safety, Being in a house at night without lights is not just inconvenient...... it can be hazardous.
OK the manufacturers and the people who wrote the " regulations " may consider loss of lights is acceptable. Is it acceptable in real life ?
Why are we losing lights?
Because the defective / damp fan unit is causing the RCD or the MCB to trip thus removing power from the lighting circuit to which the fan is connected. Until the fam is disconnected from the lighting circuit the RCD or MCB cannot be reset.
How is that different from any other fault on a lighting circuit?
what does MI stand for please.
but I'm asking if the fan also requires a Fuse Unit to go in next to the Isolator.
Some manufacturers would disagree with this.
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