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Emergency Light Test Switch.

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Is it o.k. to use a non switched fused connection unit as an emergency light test switch? If not why not?


Z.
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  • 0
    I would agree with the 'why do you want to' when there are perfectly good products available designed for the purpose.  Have you got one left on the van?


    Down sides I can see are:

    1:It would be 'unexpected' by someone else carrying out a later test - but some good labelling should get over that

    2: Depending on the FCU it could be a bit fiddlier to get the fuse out and back in again than using a fishtail keyswitch

    3: The fuse could possibly blow and not be noticed, leaving a non-savvy user without their emergency lighting supply maybe.  A sturdy bit of 6mm studding in the FCU in place of the fuse would fix that though - assuming the circuit protection is good enough elsewhere.  Arguably the risk of the fuse blowing is no greater than that of the OCPD tripping/blowing - but it could confuse a later spark as to where to look for the problem!


    None of the above are a really good reason not to.....but:


    From a regs perspective, I would think this is regarded as 'functional switching' (switching for the function of testing emergency lighting) and as such is not permitted by means of an unswitched FCU by table 537.4.


    Jason.
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  • 0
    I would agree with the 'why do you want to' when there are perfectly good products available designed for the purpose.  Have you got one left on the van?


    Down sides I can see are:

    1:It would be 'unexpected' by someone else carrying out a later test - but some good labelling should get over that

    2: Depending on the FCU it could be a bit fiddlier to get the fuse out and back in again than using a fishtail keyswitch

    3: The fuse could possibly blow and not be noticed, leaving a non-savvy user without their emergency lighting supply maybe.  A sturdy bit of 6mm studding in the FCU in place of the fuse would fix that though - assuming the circuit protection is good enough elsewhere.  Arguably the risk of the fuse blowing is no greater than that of the OCPD tripping/blowing - but it could confuse a later spark as to where to look for the problem!


    None of the above are a really good reason not to.....but:


    From a regs perspective, I would think this is regarded as 'functional switching' (switching for the function of testing emergency lighting) and as such is not permitted by means of an unswitched FCU by table 537.4.


    Jason.
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