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Topic Title: Special test meter required
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Created On: 08 November 2012 03:40 PM
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 08 November 2012 03:40 PM
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Avatar for mossep.
mossep

Posts: 347
Joined: 05 December 2010

Hi,

I am after a meter to test the accuracy of electric meters in some caravan pitch supply boxes. Some customers are refusing to pay what seems like excessive bills and the site have asked me if the meters are working correctly. Anyone know of a simple to use meter that can do this? Or should I just plug a fixed load into the pitch supply box and see if it is clocking the right amount of kWH units?

Thanks

Martin

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 08 November 2012 03:55 PM
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AJJewsbury

Posts: 11553
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I think suppliers usually just stick a 2nd ordinary meter in series for a while and compare readings, when meter accuracy has been questioned.

Is there another level of metering already in place? - e.g. the camp site's overall supplier's meter? How does the sum total of the pitch meters compare with the supplier's meter readings?

Plugging in a known load might be a simple enough solution - although beware of the limitations of nameplate ratings (is it at 230V, 240V? what's the manufacturing tolerance?). One of those plug-in energy monitors might provide "reassurance" that your load is in the right ball park. (Rather than having to trace to national standards etc).

I guess the other part of the equation is the price/kWh the site are selling the elastic trickery on for....

- Andy.
 08 November 2012 03:57 PM
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OMS

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The site owner is under a legal obligation regarding the resale of electricity (ie not more than he paid for it plus standing charge) - he can recover other costs but not via the private meter

Your first check would be sum of all the private meters against the owners site meter - that should give a reasonable overall guide to existing meter accuracy.

From there you could get into counting pulses against a known load - or better would be install a check meter if there is room

you can get good quality compact meters from someone like Elster metering

Regards

OMS

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Failure is always an option
 08 November 2012 04:13 PM
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Legh

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Plugging in a known load might be a simple enough solution - although beware of the limitations of nameplate ratings (is it at 230V, 240V? what's the manufacturing tolerance?). One of those plug-in energy monitors might provide "reassurance" that your load is in the right ball park. (Rather than having to trace to national standards etc).


A good quality PAT will give you the 'known' load. Something small and high wattage such as a kettle plus you get your tea thrown in as well !.

Legh

-------------------------
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 08 November 2012 04:15 PM
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mossep

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What I think I will do it get a waterproof gewiss type box and house a new meter in it, and wire it up with a 16A plug and a 16A socket built into it. I can plug this into the offending pitch supply box and the caravan into the new box, this way the 2 meters can be monitored to check the are reading the same.

Does this sound plausible?

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 08 November 2012 04:16 PM
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rocknroll

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Back in my troubled youth the procedure for checking meters was quite simple, we turned up with a known load, basically a big resistor in a box an amp and voltmeter and recorded the info over ten cycles then did the calculation, the tolerance then was 0.5%, if greater the meter was changed.

If these are digital meters can you not gain access to the menu to see as OMS pointed out what is the landlord charging per unit?, if it is high then this might be an issue for the tenants and one of the consumer action groups.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 08 November 2012 04:18 PM
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mossep

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This is a caravan park , they are a law unto themselves. I've no idea what they charge but its the amount of units that some of the caravans a using that seems high.

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www.mossep.com
 08 November 2012 04:39 PM
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OMS

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Originally posted by: mossep

What I think I will do it get a waterproof gewiss type box and house a new meter in it, and wire it up with a 16A plug and a 16A socket built into it. I can plug this into the offending pitch supply box and the caravan into the new box, this way the 2 meters can be monitored to check the are reading the same.

Does this sound plausible?


Entirely - just get a meter with a known standard ie approved by the Office of Gas and Electricity Markets (OFGEM) in compliance with European and British metering legislation - the meter will have an approval number.

This is a caravan park , they are a law unto themselves. I've no idea what they charge but its the amount of units that some of the caravans a using that seems high.


They might think that, but consumerlegislation will be on the pitch holders side.

Is this a recent thing - heating a poorly insulated tin shed with an electric fan convector does consume a reasonable kWh figure

Regards

OMS

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Failure is always an option
 08 November 2012 04:42 PM
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rocknroll

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Is this a recent thing - heating a poorly insulated tin shed with an electric fan convector does consume a reasonable kWh figure




regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 08 November 2012 04:56 PM
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OMS

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Originally posted by: rocknroll

Is this a recent thing - heating a poorly insulated tin shed with an electric fan convector does consume a reasonable kWh figure




regards


What ? - have I been naughty

OMS

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 08 November 2012 05:13 PM
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rocknroll

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LOL To some probably but amuses me sometimes how these people tell all their friends they are living outdoors in a caravan but find it hard to adopt the 'outdoor life'

To me outdoors means, throw an extra jumper on, light a fire, barbeque (not under the awning) a few beverages and then retire.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 08 November 2012 05:23 PM
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OMS

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LoL - that's just camping, Rock - living outdoors is what happens when it all goes pete tong and you are homeless -

Regards

OMS

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 08 November 2012 07:57 PM
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Jaymack

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Originally posted by: mossep
I am after a meter to test the accuracy of electric meters in some caravan pitch supply boxes.

I had an irate owner who let out her caravan on a rented pitch for 6 months, charge was all found with no separate charge for electricity costs. No records of meter readings, apart from the initial one and the last one for the let organised by the site office, DOH!

I have a small single bar heater, this is virtually 1kW at 240V. I connected this for an hour with a voltage and current check, the meter clocked 1 unit as the photos showed - before and after. I recommended that the owner take a deposit for power, install a coin meter, or have regular meter readings taken.

Regards
 09 November 2012 06:40 AM
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ebee

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My understanding is that the max you can resell electricity for is the amount you paid for it and not a penny more (as OMS said including standing charge etc). Seems a bit harsh to prevent profiteering - I could understand a cap of say +10% max.

I suppose one way around it is to make it all included in the price and say charge extra rent to include it.

Check meters are readily available from wholesalers and can be quickly wired up to work alongside any existing, run a few KW and compare results. If a big difference then its time to get more serious

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Regards,
Ebee (M I S P N)

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 09 November 2012 03:14 PM
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Delbot321

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I used to do meter checks for regional electricity compnay and as has already been said we used to connect up a know load for 10 minutes and count the pulses/disc turns and check the accuracy. If that didn't placate the customer then a second check meter was added and both read together over a week to see if there was a difference.

One thing that hasn't been said, although fairly obvious, the first thing to check is to remove all connected loads and ensure the meter is not moving - some can have a creep which will obviulsy mean its readings are worng. Then reconnect they installation (in your case a caravan) without any loads on to see there is still no load on the meter as there could be something else connected.

To anyone suggeting that you can add all the meters on a site to achieve a compareable total load - that is unlikely to work - any reasonable size caran park will have street lights, shower/toilet blocks, security huts/cameras, groundsmans huts and any other number of things connected that will all be unmetered so it just won't added up.
 09 November 2012 03:33 PM
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AJJewsbury

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To anyone suggeting that you can add all the meters on a site to achieve a compareable total load - that is unlikely to work - any reasonable size caran park will have street lights, shower/toilet blocks, security huts/cameras, groundsmans huts and any other number of things connected that will all be unmetered so it just won't added up.

But you can do some simple 'sanity checks' - e.g. if total of pitch meters exceeds the site meter, then you can be pretty certain there's a problem straight off. "Street" lighting etc should be estimateable - even if it's just rough worst-case figures (e.g. total current x 12 hrs day), if the showers are electric say one 10 minute shower per pitch per day. It doesn't have to be at all precise - if many customers have actually noticed over-reading meters they must be out by a large factor. You don't need precise calculations - simple rules-of-thumb or 'fuzzy logic' can serve quite well to suggest whether you're on the right track or not and so where to direct more detailed investigation.

- Andy.
 09 November 2012 04:08 PM
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OMS

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To anyone suggeting that you can add all the meters on a site to achieve a compareable total load - that is unlikely to work - any reasonable size caran park will have street lights, shower/toilet blocks, security huts/cameras, groundsmans huts and any other number of things connected that will all be unmetered so it just won't added up.


I didn't say it would - just that it would give you an initial indication if things were badly adrift.

Even unmetered loads can be sensibly estimated so if it really doesn't stack up, you have a starting point for further investigation

Regards

OMS

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 12 November 2012 07:25 PM
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perspicacious

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"I am after a meter to test the accuracy of electric meters in some caravan pitch supply boxes. Some customers are refusing to pay what seems like excessive bills and the site have asked me if the meters are working correctly. Anyone know of a simple to use meter that can do this? Or should I just plug a fixed load into the pitch supply box and see if it is clocking the right amount of kWH units?"

My first thoughts are that the "tin tenters" (or "shed pullers") have been used to an all inclusive £2 or £3 a day fee for a pitch with electric and made sure they got their money's worth by having their electric heating on with the windows open and a heater going in the awning.

I suspect that the site owner has now metered the pitches due to not recovering his costs of supplying "unlimited" electric and the "nomads" are now having to pay for their previously unfettered usage.........

They could of course use their bottled gas..........

Regards

BOD
 12 November 2012 09:57 PM
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MAXMIRA

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I would suggest using a calibrated meter in series and leave running over for 24hrs. You can pick one up on ebay for £15-25
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