Extractor fan query

Discussion in 'Electricians' Talk' started by Jiten, Oct 12, 2017.

  1. Jiten

    Jiten Member

    Hi guys

    I've come to a relatives house as they have not had their extractor fan in the bathroom work for a while.

    Cut a long story short, I opened the extractor fan and found three core an earth. Who ever done this cut off one of the wire (switch live) an they connected to the double pole isolator switch for the shower.

    What this person has done is run a permanent live from the shower swtich and neutral, cutting out what should really have been a switch live. This has then gone back to the extractor fan.

    Now this fan has a timer an there is nothing to activate the extractor fan to work, which is the problem.

    My relatives have a flat roof so running the three core to the light switch would make too much mess and cost more for them as the would need to bring in a plasterer.

    My thought was to just run a fused spur from the shower isolator switch (6mm on the incoming side and then the 1.5 3core and earth to the outgoing) this would just act as an isolator switch.

    Any opinions on something which may be better guys
  2. Jiten

    Jiten Member

    Just to confirm if I do a fused spur it will have no swtich live. Just an isolator
  3. Bazza

    Bazza Well-Known Member

    Just link, on the fan, the L to the switched live. Then connect the L and N from the fan (and the earth) to the output of the FCU.
    The FCU then becomes the fan on/off switch.
    Oh yes. FCU fuse = 3amp
    tore81 and Jiten like this.
  4. Jiten

    Jiten Member

    Thanks Baz, as it's of a shower DP switch my concern was should I use 6mm twin earth for the power supply to the FCU or should I just use normal 2.5 twin earth
  5. Bazza

    Bazza Well-Known Member

    I doubt you'll get two 6mm conductors in the back of the DP switch. 2.5mm will be OK.
    Jiten likes this.
  6. Bob Rathbone

    Bob Rathbone Active Member

    The fan must have an over run facility, perhaps use a fan with a PIR in it, then you only need a phase and neutral with CPC and the fan will start when the room is occupied. Then you can take your supply from a convenient source, not the shower circuit, it is an exclusive circuit intended only to supply one appliance.
    Jiten likes this.
  7. Bazza

    Bazza Well-Known Member

    Why? Maybe there is an openable window.
    Jiten likes this.

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