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 56 replies
  • Subscribers 32 subscribers
  • Views 7069 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Local Isolation For A/C Internal Units

Sparkymania
Hi

Doing EICRs, and the remedials resulting from them.


An issue had been raging as to whether an internal unit needs to have a local isolator.

There have been 2 schools of thought over this issue with others I am working with.


First one:

It is a an electromechanical piece of equipment and needs a local isolator even though it is being fed by an external unit that has it's own isolation.

Second one:

It is fed by the external unit and they are both one piece of equipment even though they are split with the two parts in different places. Turning off the isolator to the external unit isolates all the equipment.


In my opinion a local isolator is still needed as there is no way of knowing if the internal unit is definitely part the the external unit being isolated. It may just be off at the controls.


I have come across many A/C units that have been installed by A/C engineers and they have not put an isolator on the internal unit. I'm wondering if there is a reason that they don't or if it's just ignorance of the regs on their part. I would have thought their training would have included that. Is there something that they know that means they don't need to install an isolator to the internal unit?


Anyone have any thoughts?


Thanks

Parents
  • 0
    i have just been through the regs as I was thinking of the term "local isolator" and wondered if that term is actually used. Everyone uses it when reporting no "local isolator" for any equipment that you would expect to have one for maintenance. 

    However, there is no term "local isolator" or "local isolation" in the regs.


    In the context of this post it is under "switching off for mechanical maintenance". Funny thing is there is no "switching off for electrical maintenance" section.

    464.2

    537.2.4

    537.3.2.2

    537.3.2.4

    Nowhere does it say that this has to be local to the unit.

    My company is obsessed with local isolation for everything but I'm now wondering about this being reportable, especially as code 2. (I would report these as code 3 but it would be changed to code 2 when we get the remedials list back).


    I think local isolation, a lot of the time, is merely a matter of convenience. For example, a fan isolator in a bathroom. Inconvenient if you have to isolate the whole circuit but not reportable on EICR. 

    Admittedly, the A/C unit is different as you can turn of the wrong isolator in a group of external units. If I was working on an internal unit isolated from an external unit I would feel safer if I had local isolation. It's not always obvious what feeds what. I can't count the amount of time I've had to spend on identifying them when testing. Problem is even after that I'm only required to label the isolator with the circuit ID, never what room it feeds. I've never seen one labeled with that.

    This is where the regs come in. It states that it should be clearly labeled as to what it's isolating if not obvious by position and it cannot be obvious by position as regards the internal unit. 




Reply
  • 0
    i have just been through the regs as I was thinking of the term "local isolator" and wondered if that term is actually used. Everyone uses it when reporting no "local isolator" for any equipment that you would expect to have one for maintenance. 

    However, there is no term "local isolator" or "local isolation" in the regs.


    In the context of this post it is under "switching off for mechanical maintenance". Funny thing is there is no "switching off for electrical maintenance" section.

    464.2

    537.2.4

    537.3.2.2

    537.3.2.4

    Nowhere does it say that this has to be local to the unit.

    My company is obsessed with local isolation for everything but I'm now wondering about this being reportable, especially as code 2. (I would report these as code 3 but it would be changed to code 2 when we get the remedials list back).


    I think local isolation, a lot of the time, is merely a matter of convenience. For example, a fan isolator in a bathroom. Inconvenient if you have to isolate the whole circuit but not reportable on EICR. 

    Admittedly, the A/C unit is different as you can turn of the wrong isolator in a group of external units. If I was working on an internal unit isolated from an external unit I would feel safer if I had local isolation. It's not always obvious what feeds what. I can't count the amount of time I've had to spend on identifying them when testing. Problem is even after that I'm only required to label the isolator with the circuit ID, never what room it feeds. I've never seen one labeled with that.

    This is where the regs come in. It states that it should be clearly labeled as to what it's isolating if not obvious by position and it cannot be obvious by position as regards the internal unit. 




Children
No Data

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines