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Topic Title: Metering advice
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Created On: 31 August 2012 07:51 AM
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 31 August 2012 07:51 AM
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Avatar for dickllewellyn.
dickllewellyn

Posts: 1150
Joined: 19 March 2010

Morning all

I posted on here a couple of months ago about metering, and was kindly directed to a couple of websites. One of the companies I was directed to was universal meters where I purchased three of These Or here

I have a couple of concerns. Firstly, the connection seems to be by way of passing conductors through the meter, which then has a screw in each tunnel to pierce the insulation. Is this type of connection acceptable? My second concern is weather it meets the standards required for use in the UK. It does have a CE logo, but I know these can be added at will. There is also IEC 62053-21 and an RoHs stamp.

I would be greatfull if anybody has experience of these meters and standards, and also if anyone can suggest a way of installing them safely.

Thanks as ever

Dick

-------------------------
Regards
Richard (Dick)

"Insert words of wisdom and/or witty pun here"
 31 August 2012 09:13 AM
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OMS

Posts: 19676
Joined: 23 March 2004

Hi Dick,

Is this the type where you just pass the cable straight through the meter and then just tighten a small terminal screw to pierce the insulation just to power the meter.
the internal meter configuration then just acts as a single turn CT - the terminal isn't actually carrying line current

If so, I've seen them in action, and I can't honestly say i was too impressed. I guess you never really get a sense of quality when you read the manual and it looks like it was translated in the back room of the local takeaway !!

If you are really unhappy, you might want to try these guys:

Secure Meters Ltd
PRI House
Moorside Road
Winchester
Hampshire
SO23 7RX.

Not too far from you I recall - and they supply a client of ours who is extremely focused about all things safety related so it's really good kit.

If you want fully functional ask for a Meter type MT3 - if just kWh - ask for an MT4 - tell them the client is MoD

regards

OMS

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Failure is always an option
 31 August 2012 11:34 AM
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Avatar for dickllewellyn.
dickllewellyn

Posts: 1150
Joined: 19 March 2010

Hi Oms

Thanks for your reply, you are quite correct about the way they are connected.

I will have a look at Secure Meters and see what they can offer, I must say I'm not keen on the ones I've received! I will remember to add the MoD line too!

-------------------------
Regards
Richard (Dick)

"Insert words of wisdom and/or witty pun here"
 31 August 2012 12:12 PM
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Avatar for OMS.
OMS

Posts: 19676
Joined: 23 March 2004

OK - as i said, I've seen them installed and wasn't overly impressed - that said - the terminal isn't carrying full load as the conductor isn't broken (much) - so if you have them, leave them in ? - and go elsewhere in future

As for "Secure Meters" - just sharing the love - no connection BTW, just a customer

regards

OMS

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Failure is always an option
 31 August 2012 05:51 PM
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alancapon

Posts: 5770
Joined: 27 December 2005

A kWh meter requires a voltage and current measurement to function. Threading the tails through the meter will take the phase through a CT in the housing, giving the current measurement. The voltage measurement and the power for the electronics of the meter is made by the insulation piercing connections, and will be no more than a few milliamps.

If the meters are of the required accuracy for your purpose (Class 1 being about 1%) then you shouldn't have any problems. That said, they will probably not be suitable if you are expecting the DNO / Meter Operator to bill against them, as they may not be type approved to the correct standards.

Regards,

Alan.
 31 August 2012 06:27 PM
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Avatar for dickllewellyn.
dickllewellyn

Posts: 1150
Joined: 19 March 2010

Thanks for your reply Alan.

Don't worry, there's no billing requirements as such, just an idea for power, lighting, and heating requirements of offices, with the acceptance that the farm is using the rest. It may be that in time we will be adding more metering, as the drier is used by a partnership, there are a couple of workshops, and there may be yet another third party taking a workshop.

-------------------------
Regards
Richard (Dick)

"Insert words of wisdom and/or witty pun here"
 01 September 2012 12:46 AM
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alancapon

Posts: 5770
Joined: 27 December 2005

To be honest, by having the tails passing through the meter body, rather than terminating in it, you have "engineered out" four connections that can carry a reasonably high current and need to be correctly tightened.

Regards,

Alan.
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