Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 36 replies
  • Subscribers 32 subscribers
  • Views 2702 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

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. 

  • 0
    132.1 (ii)., 301.1


    Z.
  • 0
    V R F means ?
  • 0
    Hello ebee, I was just looking that up. It could be Variable Refrigerant Flow, or Virtual Routing and Forwarding. Too many variables here. It leads to confusion. Abbreviations are just so annoying these days.


    Z.
  • 0
    Yes Zoom I hate Abbreviations unless explained their meaning. It turns me all Victor Meldrew
  • Former Community Member
    0 Former Community Member
    Sounds like some one has decided to wire up the internal fan coil units or cassettes on a heating/cooling refrigerant system from local lighting circuits


    The indoor units aren't heavily loads and provided the lighting circuit has been designed for it then probably no problem - switching off for mech maintenance could be done via a local DP fused spur


    It's pretty badger though


    OMS


  • 0
    Subject to the usual caveats about circuit design, I see no problem.

    If the VRF units have a local switch or fused connection unit, then only under exceptional circumstances would the lighting circuit have to be isolated for maintenance.


    A local switch or fused connection unit will almost certainly provide double pole isolation for work on the VRF units, which is preferable to the almost certainly single pole MCB.

    Also a local control probably wont need locking off as it is likely within reach and sight of the person working.


    I presume that VRF is variable refrigerant flow, in which case the loading is often in the region of 100 watts. I see little merit in two separate circuits, one for ceiling mounted lights and another for ceiling mounted VRF units in the same area.

    It could be argued that 1.0mm cable is prohibited, but 1.5mm or 2.5mm is almost universal in non domestic in any case.
  • 0
    That's correct re VRF Units. They are around 100watts ea. I think the key word is maintainability. I wouldnt be happy if an engineer turns up on site and has to isolate the lighting when working on the VRF unit just because they are wired on the same circuit even if the VRF Unit has a DP Isolator, I think it's not good practice for the sake of another circuit being installed. For me they should be seperate circuits.
  • 0
    Why would an engineer working on the VRF system need to turn off the lighting circuit via an almost certainly single pole MCB, in preference to isolating the equipment by a local and almost certainly double pole switch.?
  • 0
    It is an internal policy to switch off at source and lock off the MCB due to an historical incident.
  • 0
    Would a local lockable DP (double poled)  isolator not accomodate this?

Community Rules & Guidelines