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VRF Equipment fed off local Lighting Circuits

Eddie Currents
What are your thoughts with VRF Equipment being fed off local Lighting circuits – For me not good practice and strongly oppose this but i cannot find a Clause anywhere in the new Regulations. Has anyone ever come across this before or am i being too pedantic ? The VRF Units will have local isolation but for me its still a problem as you will lose your Lighting if you need to switch off at the Breaker for any reason like switching for Mechanical Maintenance. 

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    It would yes but just not keen on the idea of them being wired on local lighting circuits for the sake of another seperate circuit or 2. Maybe I'm over thinking this
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    So they are a small load for a combined lights and fans circuit.

    Does it affect anything else, like the margin for not tripping an RCD and plunging the place into darkness, or a need for earth bonding to metal plumbing. This rather depends if this is well thought through or a quick hack.


    For the same reason that more than one lighting circuit serving a given area is a good idea, separate circuits here would probably be better, but not a regs requirement, except in the sense of minimising inconvenience.
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    Carlwordsworth:

    It would yes but just not keen on the idea of them being wired on local lighting circuits for the sake of another seperate circuit or 2. Maybe I'm over thinking this 




    What is the worst that could happen if a service engineer turns off a switched fused connection unit and removes the fuse to work on the equipment, after affixing a warning notice. You could always install new isolating switches high up adjacent to the units for isolation by maintenance engineers, perhaps even in the false ceiling if there is one.


    I'd send a strongly worded memo to "management" to cover my a**.


    How large are the areas in question? Is there emergency lighting or borrowed light (Indirect lighting from other areas say coming in through glass) in case of a lighting failure?


    Z.

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    Yes thats what I'm thinking - great advice thanks
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    The problem is not how to isolate the cooling units as they have double pole switches, it is how to isolate the lights.


    But does it matter?


    Andy B.
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    Sounds similar to the common case of the toilet extract fan and light combination.
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    The other hang-up might be if these are more than fans and are semi-smart units that lose their settings when the power is briefly interrupted.. On the other hand do many places really do more isolation than turn off at the light switch to change lamps these days? (ignoring the 'what would happen in an ideal world' ). I've certainly done re-lamping of some fittings with the power on, not even off at the light switch, and it was not so long ago that we can claim the protection of back in the mists of time.
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    Agree it's the same argument with toilet fans. They will be linked to a BMS so are also on a Smart system.
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    mapj1:

    The other hang-up might be if these are more than fans and are semi-smart units that lose their settings when the power is briefly interrupted.. On the other hand do many places really do more isolation than turn off at the light switch to change lamps these days? (ignoring the 'what would happen in an ideal world' ). I've certainly done re-lamping of some fittings with the power on, not even off at the light switch, and it was not so long ago that we can claim the protection of back in the mists of time.




    Aw nawty nawty nawty Mapj1, non of ever does that! Do we? ?

  • Former Community Member
    0 Former Community Member

    Fandango:

    It would yes but just not keen on the idea of them being wired on local lighting circuits for the sake of another seperate circuit or 2. Maybe I'm over thinking this 




     

    What did the specification and drawings require ?


    Would you have the same concerns if I'd specified a LV bus bar system through the ceiling voids and told you to plug in anything you like (or would expect) in or on an office  ceiling (lights, local WIFI or mobile phone nodes, heat/cooling fan coil units, associated FCU control nodes, etc etc


    Regards


    OMS

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