Power Factor and New Power Company Digi Meters

Greg wrote:


Initially I had a bill for £29 only
Thought that's wrong...............and knowing how they work ...ie you will be billed higher at a later date I phoned them up.
They then asked what reading I had on my meter now ...and then came back with the new calculations ....£300
and according to them ....this is from a an official meter reading...to my reading ... and I've used something like 2500 units .
They told me this is out of line with what I have normally used in the past ...and even they think there is something wrong with the meter .
And I wasn't talking to a Muppet ...I had the manager of this section of British gas phone me back.
Like i said there is something wrong ... I used 11 units yesterday in the space of two hours ....that's just with my comp on and my converter and the lathe.
24 hour period of used 29 units !!!......
that's with me using the electricity like I do normally ...ie no cooking ...bought a take away ....no tumble dryer etc ...
all the best.....mark
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

That definitely sounds dodgy - 5.5 KW sounds a tad over the top for a PC and a lathe.
Your next door neighbour hasn't tapped into your supply by any chance...?
Regards, Tony
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike wrote:

Thankyou Mike
I take it that the model that measures reactive energy is the one that they should of installed.
Is reactive energy another word for power factor .
All the best.mark
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No, they should have installed the one that measures active energy as that's all that is metered domestically.

No, reactive energy is the energy that flows in the reactive part of the load i.e. the inductive or capacitive elements of the load and is measured in kVAr hours (kilo Volt Amp reactive hours)
Power factor is the ratio of the true power to the apparent power i.e. watts/volt-amps or W/VA and is a measure of how close to a resistive load it is. A pf of 1 is purely resistive and any lower value contains inductance and/or capacitance (or switched mode see below). A load consisting of pure inductance and/or capacitance has a power factor of 0 as there is no true power dissipated in it, though in reality no such pure components exist.
Another way to visualise it is that Watts are due to the current that is in phase with the voltage and VArs are due to the current that lags (inductive) or leads (capacitive) the voltage by 90 degrees.
Low power factors are a problem for the national grid as the lagging (most common) current causes heating of the distribution network so loses energy, but is not billed domestically so they don't get paid for it, industrially it is billed or at least limited by contract.
Then to get you really confused there are the now very common switched mode power supplies in everything from PCs to video recorders, these draw current in peaks but in phase so aren't leading or lagging, yet they still result in a bad power factor and heating of the grid for reasons that are just too complicated to explain here.
Greg
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I'm not happy
I phoned up Ampy the maker of this meter.
and they say it DOES NOT TAKE INTO ACCOUNT POWER FACTOR it reads only in kva hours.
MODEL NUMBER
5235A
British gas say they will not change the meter.
BRITISH GAS SAY THAT EVERYONE WILL HAVE ONE OF THESE METERS INSTALLED WITHIN THE NEXT FEW YEARS
They also say that "ALL" other electricity providers are going down the same route
so therefor you're all going to be in the same boat as me .
ie your overall electricity bills will shoot up 75 percent if you use your machinery in your workshop for a couple of hours a day...domestic
Example I used to use about three units on the old ANOLOGUE meter for ...for a couple of hours work in the workshop
This new fangled digital meter now reads 11 units of the same time period .. the new meter isnt faulty ...this guys is the future
I URGE EVERYONE HERE ...WHO HAS ONE OF THESE DIGITAL METERS FITTED TO GET IN TOUCH WITH
ENERGYWATCH
http://www.energywatch.org.uk /
PHONE
08459 060708
They wont have a clue what you are talking about ...but the more people phone this number ...the more this fraud will sink in with them.
All the best.......mark
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

INSTALLED
the
use
day...domestic
for
TO
people
Perhaps I'm missing something here, but haven't we ALWAYS been charged for KVA as domestic customers ? The 'old fashioned' spinning wheel type meters read KVA as I understand it
AWEM
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 5 Oct 2006 17:42:24 +0100, "Andrew Mawson"

I've just checked, my ABB 'digital spinning wheel' meter, about 2 years old, *says* it reads kWh. I couldn't comment on the theory of which it measures, though <g> Having said that, my bills did seem to go up substantially after it was fitted, but I used to be pleasantly surprised at how low they were with the old meter. Perhaps the old one was faulty ! Presume the meter Mark is talking about works on a different principle - does it just measure volts & amps and combine them? If so the meters are probably cheaper to make, no moving parts, that could be one reason for the change.
Tim
Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 5 Oct 2006 17:42:24 +0100, "Andrew Mawson"

You're missing nothing Andrew. The only way the new meters will read more than the old ones is either when they are faulty (unlikely) or the previous induction disc meter was under reading which is much more likely.
As the whole metering systems throughout the electricity industry, right from 23kv at 30,000 Amps on the generator, to 400kV at 3000 Amps on the transmission system, through bulk supply points at 11kV and 33kV are *ALL* based on electronic metering and have been for 15 years or so.
The figures generated, match the figures supplied less known losses. They are extremely accurate and regularly checked with two different manufacturers meters for instance at every critical point, any discrepancies have to be accounted for. The technology in them is very similar to those in the new domestic meters.
But, induction disc metering is also very accurate and they certainly don't under read by 3/11 of the usage as mentioned unless there is a serious fault. If the error came to much more than 0.5% I'd be very surprised - the statutory limit is, if I recall correctly 1.5%.
Not measuring reactive power is a very good thing for anyone running machinery. Given the choice the whole of manufacturing industry together with major commercial premises would prefer KVA only metering just like the domestic customers fortunately have. So, your meter might possibly be faulty Mark, but make the right noises and you can get it checked or replaced. It will cost you for the investigation, but if you are correct you will get all the costs back plus the cost of the overcharged electricity. Or, do it yourself and buy an induction disc meter off of ebay and wire it inline with your workshop load. Maybe buy an electronic one too and see what they read - They can be had for about a tenner a piece plus postage.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Technically KVA can be reactive power and that's usually how it's used; KWh is not reactive but a real power measurement (OK energy measurement). If the energy company charges you for energy used they must use a KWh meter, if they're charging you for amps then the KVA meter is what they should use. Industry has long been charged for KVA R whereas, until recently it seems, domestic single phase users have been charged for KWh. If you get 3 phase installed at home, you get charged industrial rates. There is a general push to get all equipment that goes through CE approval to achieve a power factor of >0.9 to reduce current (and heating losses) in the power distribution system but motors etc. won't achieve this without the use of power factor correction (PFC) networks. Martin
--
martin<dot here>whybrow<at here>ntlworld<dot here>com



Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Thu, 05 Oct 2006 19:05:38 GMT, "Martin Whybrow"

My mistake, the kVA slipped in there. I meant kWh ! All domestic meters measure kWh regardless of how they are implemented. They don't give a stuff about power factor so you can put as many motors on the supply as you like and will blow the supply fuse well before the meter starts reading anything other than kWh.
This is quite frankly a storm in teacup. If there was even the slightest hint of a problem, a great many users would have been aware of it well before now.
Sorry for these caps
A HUGE MOTOR WILL USE LOTS MORE UNITS THAN A CELLPHONE CHARGER PLUS ELECTRICITY HAS DOUBLED IN PRICE DURING THE LAST YEAR!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

My bill clearly states I am paying for kWh... nothing about power factor on it... If there metre has a design fault it's their problem, as they can't prove how much electricity they have supplied.
Regards Jonathan.
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I strongly suspect that someone is talking bollocks here. All domestic metering will tend to go electronic in the next few years (about time too). AFAICT no utility in the UK bills based solely or even partly on VA consumption to domestic consumers. Even the Energy watch site talks exclusively about kWhr.
Contracts for kWhr with an availability charge for peak kVA on a period rate are standard in industry and might be instituted by default if one has a three phase supply or if the previous bill payer had a business contract. But note that the availability charge is a fixed per day/month/quarter uplift based on peak usage.
What does your bill say? If it really said you were being charged for X many kVAhr, then simply change to another supplier, as is your right and can be done in a matter of hours. If it says that you are being charged per kWhr and you feel that the meter reading reflects kVA then demand a meter test, but be prepared to pay if the meter is accurate.
Keep us all informed as to your luck on this one...
regards Mark Rand RTFM
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mark Rand wrote:

I can only quote facts
1-3units before the meter
11 units after
if you look back a few years back when I asked about power factor, you will see when i had the fright of my life when a friend put a clip on ammeter onto one of the tailings .
it was showing that my 3 hp compressor was using 40 amps start up and 26 amps or so when running .
you guys here explained power factor to me then
and basically told me to watch what the actual meter counts .. so i did an experiment with the compressor chugging away ...with the receiver valve partly open so it didn't cut out
I did this over half an hour
and was pleasantly surprised that it wasn't using anything like 26 amps... which is ... 6 240 watts or 6.2 units an hour and the analogue meter showed it to be using something like 2500 watts or 2.5 units per hour
SO ON FROM THERE ...i believe this new digital meter is reading the same way that that clip on ammeter was reading.
so you guys are now disputing me and trying to reverse everything
do you guys work for British gas or something.
or do you trust in everything this country does to you, and tells you. .............and see no evil etc.
all the best.....mark
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

<snippage>
<more snippage>

Read what I said....
Mark Rand RTFM
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Odd then that the only reference to it on Google lists it as an energy meter, that means kW hours...
You've admitted that you don't understand this field so I suspect that you're simply getting confused when talking to these people. A digital power meter does not "correct" for power factor, it measures true power regardless of power factor. If the meter is to display power factor it has to calculate it as a secondary or derived value.
If you doubt what I'm saying please go to this site: www.deepseaplc.com click on products and scroll down to the 5520 which is one of my designs, in fact most of them are. Open the PDF manual and you will see it meters everything that's been mentioned here and a lot more besides. I can explain exactly how the hardware and software does this if you want but it's boring 8-). Please take my word for it that this area is very complicated and even experienced electrical engineers get confused, so there's no need to take offence !.
Does you bill still refer to kW hours?, if so they can't possibly be metering kVA hours as this would be fraud, pure and simple, there is no way they can know the kW hours you've used from metering the kVA hours, they can only know the maximum you could have used IF your load were purely resistive, and no one is.
Whatever the situation you have, you can fit pf correction capacitors to your machinery to bring the pf back near to unity, not a bad idea as the world burns a hell of a lot of fossil fuels just to heat up the generation and distribution systems because of bad pf. This is why the generators are planning to meter kVAr domestically as they have been doing industrially for many years, but I've not heard any suggestion they intend to install kVA hour meters as the way to do it, instead they intend to install meters that measure both kW hours and KVAr hours.
Greg
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Greg wrote:

Any suggestions on how to size PF capacitors? It's certainly something I have never even thought about.
We have just had southern electricity tell us they will raise our direct debit to 200 a month!! Seems we been paying too low an amount for a fair while. Now I'm closely monitoring the meter.
Might pay to get three phase installed if I'm actually using that much more than average!
Wayne...
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

It's a bit comlicated and I'm falling asleap so I'll get back to you...

Power factor correction will only help your bill if you are NOT just being metered on kWh, though it will help save the planet a bit 8-).
Greg
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You're sounding more and more like a troll, did you just ask them to change the meter because you thought it faulty as I suggested or did you try and be all clever with them, arguing technicalities you don't understand, I wonder.
Greg
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Greg wrote:

Yup anyone on these news groups ...that seems to be loosing an argument gets called a troll ...that's how they work ...so it seems
And I've also noticed how people get ganged up on as soon as someone seems to get something wrong ... other people jump in and say the persons wrong ..........just for the hell of it .
and if that becomes more likly here ..i will simply not answer any more questions on the subject ...or read it.
nope did not argue tech with them
just said that 1-3 units used before 1.5 to 2 hour period
and 11 units used after meter install over same period .
I just said "is this something to do with this power factor malarky...and thats it "
they guy from British gas said he understould power factor .
and he thought himself that something was amiss with the way these meters read the power.
(AS his father had a small machine shop at home ...and had been grumbling)
he said, he did all he could to convince his superiors that i had a case .. he said there wasn't any budging in them .
I have an old analogue meter (faranti same as the old one) ...i know it was bought from a car boot sale ...but its all i have to check this out myself ...so cant vouch for the blooming thing
shall be putting it on at the weekend ...to see what's going on myself.
YOU say you designed them Greg ...then I wouldn't expect you to knock them.
All the best...mark
Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
mark wrote:

http://www.howtocomplain.com/cgi-php/complain1.php3?MajorID=1&MinorID=2&ID=5
--
Posted via a free Usenet account from http://www.teranews.com


Add pictures here
✖
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.