Eddy Currents affecting energy check meters.

[Wrecker]

Hiya everybody I'm a long time reader first time poster of this wonderfull forum and I just wanted your opinion on Eddy currents?
I was asked to test some electricity meters on a static caravan park recently as the owners were complaining about their bills, and whilst i was in the meter cupboard I noticed all of the meters were fed through metal trunking with individual holes for the supply live, supply neutral, load live and load neutral. I was just wondering if eddy currents could be affecting the readings as there is over 40 meters in this cupboard over all 3 phases with every cable passing through its own hole in the metal trunking which is all interconnected and I was just worried that there could be induced currents floating through the trunking affecting the meters?? Any thoughts on this would be gratefully received!!

 

[KAS1]

That's a very good question, I would of though yes, by how much I don't know, would have to give this a lot more thought, I'd like also to hear other people's thoughts

 

[chrish_1977]

It depends on what the distance is between the holes/phases and also what material the trunking is made of. Easiest way to eliminate would be to cut slots between the holes effectively joining them up

 

[Knobhead]

This simple answer is no, it will not affect the meter.

The problem is now the singles passing through single holes. A slot needs to be cut between them.

 

[Knobhead]

Was hoping this could have been interesting about fiddling meters. No such luck!

 

[pete555]

got to agree with last 2 replies definately requires slotting and especially if metal trunking

 

[Marvo]

I'd say it might be possible but it's extremely unlikely. Install a second reference meter on one of the supplies and do some real life calibration tests with the wiring in the trunking and again with the wiring out of the trunking.

 

[Knobhead]

got to agree with last 2 replies definately requires slotting and especially if metal trunking

Only in steel.

 

[Fast&Rough]

Rigged meter for tony

 

[Knobhead]

You could have used the correct sleaving.

P.S. turning it on it's side only worked with the old meters.

 

[Wrecker]

A big thankyou to everyone who replied to my question! I will tell the customer it's not likely to be affecting the meters but i doubt he will be up for paying me to slot all the trunking between the holes even if it is a code 2 recomendation! I will tell him about the idea of installing a secondary meter to check aginst one of the installed meters if the customer is willing? Does anyone have any ideas of a foolproof method of testing an electricity meter without resorting to directly connecting a known load (2kw fan heater), and then measuring the load drawn with a clamp meter, and timing how long it takes to use 1 unit with a stopwatch??

 

[ayjay]

hi, maybye the park owners are charging a high rate for the power?

 

[Engineer54]

Hire a power analyser for a week and hook it up to read the total installations load. you can then compare KWh readings for a given period between the test kit and the DNO meters.

It will also give you a lot more information, which in many cases, give you areas to investigate further!! These things are worth their weight in gold, ...if you know how to use them and able to understand what they are telling you!!

 

[richy3333]

As an aside could it be a charging issue between the campsite and the customer? If so are the owners aware of the rules about charging - what and how? Chatting to a customer of mine recently about meters revealed that they can be as much as 30% out if they aren't the certified ones