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 13 replies
  • Subscribers 40 subscribers
  • Views 5319 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

Installation of CT clamp current monitoring devices

Christopher Green

Hi there sparkys!

I work for a company who manufacture CT Clamps to measure current consumption. I'm a presales engineer, not an electrician.

These clamps, as I'm sure you know, simply clip on to a conductor in a consumer unit or elsewhere, and in our case, transmit the information wirelessly to a device which translates and presents the data in a useful fashion.

I'm working on some marketing documentation, and I'd like to be clear about the legality of installing these devices in commercial premises. In order to install these devices, one simply has to clip them around an insulated live conductor, there is no need to turn off the power, or touch any bare metal. I know that British Gas and other companies hand these out to domestic consumers so that they can have a display showing how much energy they're using, so I assume that it is legal for any old idiot to clip these on to an insulated live conductor in a domestic consumer unit.

But what about commercial premises? I don't know the rules - can an unqualified/uncertified person open a RCD box or consumer unit or whatever it's called and clip these CT clamps on to a live conductor in commercial premises? Can an unqualified person even touch a commercial consumer unit?! I would have thought that regs would require a certified electrician to install these things, but one of our selling points is that they don't require professional installation or any permanent modification to the wiring, as they simply clip around an insulated conductor.

I've attached a picture of some of these clamps installed in one of our consumer units. These were actually installed by a certified electrician, but only through coincidence - the guy who did my job before me just happens to be certified, as he worked as an electrician before he started this job!

Any advice on the legal requirements of installing such devices would be appreciated. Obviously it's very important that our marketing materials don't advise anyone to break the law!

I'm asking this question from the UK, but we sell these devices globally, so any advice on different rules in Europe or America or anywhere else would also be welcome.

Thanks everyone!

Parents
  • 0

    The law in the UK does not prevent anyone from opening a fuseboard, or anything else (well after the meter anyway) though some insurance policies may be invalidated in commercial situations.

    There is no single certificate that makes someone an electrician. In the same way the wiring regs are not a legal requirement in most situations either, so what is 'competent' enough  is cloudy.

    Now the level of understanding needed to fit one of these is pretty minimal but many large commercial  boards, especially older ones, have large blocks of live metal exposed, perhaps even when the final circuits are nominally 'off' . The older wylex domestic  designs are another case in point

    However,  as per Adrian above, above any activity  that has the potential to expose live terminals should not really be recommended to unskilled/incompetent persons who cannot accurately recognize the risk.

    The single meter tail is ideal, as it is outside all the containment, almost anything else involves opening things up.

    I'd restrict the advice to suggesting that it is a DIY task only in those cases that do not involve opening up a distribution board, or anything that opens with a key or screwdriver. If tools are needed then it falls into the 'if in any doubt take the advice of a competent person '  category..

    The US is more fussy about who is allowed to do what, but less strict on the testing aspect.

    Mike

  • 0 in reply to mapj1

    Oh wow, that Wylex link you sent me is exactly what I have in my house! I'm selling the place at the moment ,thank God!!

Reply
  • 0 in reply to mapj1

    Oh wow, that Wylex link you sent me is exactly what I have in my house! I'm selling the place at the moment ,thank God!!

Children
  • 0 in reply to Christopher Green

    Well before you go, switch it off, remove all the fuses and then take a small screw driver to it and use the opportunity to open it up for yourself and see what exactly is inside a  consumer unit for real.  It is not always like the sales pitch photos on the  websites you know ;-)

    keep your fingers off the bare metal and..

    then put the lid  straight back on...

    and realize why the instructions must ask folk to refer to someone suitably skilled when it involves opening something up.

    There is plenty of that older stuff still in service, even if it was last installed in the early 2000s, your instructions must allow for that.

    Mike.

    ps the brown ones are more 1960s ,but the white ones of more or less the same style were sold and being  fitted until about 2005. (and I last put one in in about 2002 personally....)

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