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Anonymous Poster #1

Digital KWH Meter

08/16/2013 10:35 PM

Hi Guys,

Recently, we have just install a new KWH meter at the Main Switch Board, but after 9 mths the reading seems to be inaccurate.

CT:1600/5A Class 1 15VA.

KWH meter reading as shown:

Day 1:1633516 kw

Day 2:1578031 kw

Day 3:1582702 kw

The running load is about 30-40% 9f the full load.

Do anyone came across this problem with their KWH meter?

Thanks & Regards

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Guru

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#1

Re: Digital KWH Meter

08/16/2013 11:31 PM

No.

What makes you think anything is wrong??

What does customer service say the problem is? Have you contacted them? Do you know who made it? Installed it? Services it? Knows anything at all about it? Like maybe the brand and model number??

Have you looked for answers on the manufacturer's web site? Anywhere?

Do you know what the accuracy is supposed to be???

We can't read your mind, we don't have a crystal ball and Carnac is dead.

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Anonymous Poster #1
#6
In reply to #1

Re: Digital KWH Meter

08/17/2013 12:56 AM

Hi Lyn,

I didnt say its wrong,i mean i puzzled that the KWH Meter will go reserve.

Thanks for your time.

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#7
In reply to #6

Re: Digital KWH Meter

08/17/2013 12:57 AM

Switch the leads.

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Commentator

Join Date: May 2013
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#2

Re: Digital KWH Meter

08/17/2013 12:14 AM

What you have described is the instantaneous real power (KW) and not energy (KWH). KWH wil be cumulative and increase on daily basis, whereas real power is a varying quantity based on the load at the measured instant. By the way, based on the very limited and incomplete data furnished by you, as per the meter reading your load is around 70% and not 30 to 40 % as indicated by you. Is there any chance that the meter has not been programmed properly for correct CT & PT ratios? Of course I am assuming it is 415 volts LT metering.

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Anonymous Poster #1
#5
In reply to #2

Re: Digital KWH Meter

08/17/2013 12:52 AM

Its a KWH Meter.Electronic Energy Meter MH-MEM34L.

The current running load is around 500A,Full load is 1600A so its around 30% not the 70% as you have mentioned.

Its been tested before by the vendor c/w test report and it was installed by the switch board contractor.

Yes,it was 415V at LT metering.

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Power-User

Join Date: May 2010
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#3

Re: Digital KWH Meter

08/17/2013 12:33 AM

Do you have any calibration certificates for this kWH meter and CTs?... Do you mean the day 1,2, and 3 are the days 9 months ago when you installed the meter?...in that case what is the reading at present days?...

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Anonymous Poster #1
#4
In reply to #3

Re: Digital KWH Meter

08/17/2013 12:47 AM

Yes,i do have the calibration certificates for that.

Day 1 is on thursday(15/08/13),Day 2 is Friday(16/08/2013) & Day 3 is Saturday(17/08/2013).

The Present reading is still at 1591234 KWH.

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Associate

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#8

Re: Digital KWH Meter

08/17/2013 1:37 AM

U need to check parameter settings of KWH meter as per commented by PATTANHIRAMAN load might be 70%-----parameyers of CT selection might be changed due to some power jerk was faced by KWH METER

u need to juat set it to factory default and reprogram all parameters and start it from zero

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#9

Re: Digital KWH Meter

08/17/2013 3:25 AM

Where is the decimal point?

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#10

Re: Digital KWH Meter

08/17/2013 10:13 AM

In one post you say these figures are kW, in another you say they are kWH. Do you understand that these are completely different values? Do you know what you are looking at?

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#11
In reply to #10

Re: Digital KWH Meter

08/17/2013 12:47 PM

Sorry its KWH...

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#12
In reply to #11

Re: Digital kWh Meter

08/17/2013 12:59 PM

Tornado already asked, but you don't really expect anybody here to take you seriously, do you?

Do you have any idea how much energy 1,591,234 kWh really is?

Do you have anyone there who understands electricity?

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Anonymous Poster #1
#14
In reply to #12

Re: Digital kWh Meter

08/17/2013 3:23 PM

The value of the KWH meter was so huge due to it had been install 9 mths ago and its recently that we found out that the value is inaccurate

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#17
In reply to #14

Re: Digital kWh Meter

08/17/2013 3:37 PM

<unsubscribe>

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#18
In reply to #17

Re: Digital kWh Meter

08/17/2013 3:46 PM

why ¿¿¿

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#13

Re: Digital KWH Meter

08/17/2013 2:00 PM

It appears that the OP's concern is that the reading decreases from day 1 to day 2.

While the totalizer on a liquid flow meter configured for 'net flow' might well decrease if reverse flow is greater than forward flow, a decrease in total (kwh) power has not been typical of electrical billing meters of my generation - the spinning wheel electromechanicals.

But in an era of co-generation, there might well be an electronic power meter that records net power, power company supplied grid power minus co-gen power put into the grid. I don't know, it's a big world out there and there are zillions of products.

It is a reasonable question - why would a power meter total decrease?

Unfortunately, this particular meter seems to be Mun Hean meter and Mun Heanians do not publish their specs or manuals on their web site, so researching the possibility of a 'net' total feature is not feasible.

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Anonymous Poster #1
#15
In reply to #13

Re: Digital KWH Meter

08/17/2013 3:29 PM

Hi Iris,

You are right, MH doesnt post anything on their web therefore I cant find any info on that.I try looking into their web but cant find any.

Im posting because im not sure what that the KWH meter will go reverse, and hope that someone here will have experience it and advise me what actual happens.

Anyway thanks for everyone time here.

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#20
In reply to #15

Re: Digital KWH Meter

08/18/2013 1:08 AM

There is a whole lot that is not clear here!

It would be useful if you were to start with a complete new set of figures, all with correct units, and for the entire period for which you have data. You mention 9 months of use, but give 3 days of data. Are those three days the first three days of the period, the last 3 days, or something else?

Is this meter installed by your utility, or by you or your company? Who paid for it? If you or your company paid for it, and the company won't provide information about the meter, then I'd say you got 'ripped off'.

Mine was installed by the utility, and the display cycles through a whole series of different numbers; only one of those is the energy in kWh.

Do you have any solar electric or other energy generating system that can connect to your power source (and conceivably make the meter run backwards)?

Yes, a kWh meter should be able to run backwards, if energy is being provided to the utility rather than being consumed. This is a moot point for the vast majority of people.

Finally, it is quite possible to add a couple of current transformers and a voltmeter connected to a recorder/data logger to determine your actual usage and verify the readings.

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#16

Re: Digital KWH Meter

08/17/2013 3:33 PM

u r saying total load is about 40% of 1600 amp ; it will 640 amp

if ur meter is installed at LT side and considering 440 V with power factor 1 with continuous and average of 640 amp. current consumption per hour as mentioned by u will gate

640 x 440 = 281600 watt per hour or 281.6 KWH

by considering ur load is same for 24 hours ur total kw consumption per day will not increase more than 6758.4 KWH

see ur previous daily logs if u get every day KWH consumption near about calculated KWH ur meter was working properly and if u doesn't get linearity for same or average load for one day ur KWH meter is showing wrong data since day one

u have provided KW or KWH (still confused because u haven't given data for KWH meter in healthy condition day before ) data from when.KWH meter showing reverse or wrong readings

better is 2 replace KWH meter with new one with same CT and take trial....

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#19

Re: Digital KWH Meter

08/17/2013 11:48 PM

Had a similar problem several years ago. Went backwards because clock was going backwards. Never had the time to find out why. Meter had a "button battery" for clock in case of a power failure. Replaced battery and ran correctly. This system was a large stand-by generator so it was stopped frequently.

Good Luck, Old Salt

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#21

Re: Digital KWH Meter

08/20/2013 4:08 AM

If you look at the Mun Hean Electronic Energy Meter (MH-MEM34L), at the bottom of the front face, does it say 3200P/kWh? P means pulses.

The actual value displayed now needs to be divided by 3200 to give you your actual kWh value.

You should contact the installers of the equipment and, get them to supply you with all the relevant data sheets for the equipment they've installed for you. They should have these to hand, as they're the ones who've purchased this equipment. This should be standard practice anyway. Once you have the data sheets you should get a better understanding of what you're working with and, in doing so have better control of over the facility you're trying maintain/support.

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Alanvaderi (1); Anonymous Poster (5); dkwarner (1); Dodgy Solenoid (1); Iris (1); JRaef (1); kianhwee (1); lyn (4); MUSUTH86 (3); old salt (1); Pattabhiraman (1); Tornado (1)

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