Unusualy High Meter Readings

12 kw and 625Kw is too big difference, If connection and meter are for fixed for few KW, say less then 100KW,I am sure its not going to survive few minuets at 625Kw,

Even a domestic earth wire will not survive if its sucking 600Kw.

By the way why don't you check line current after shutting down all the connected load, this can help you to finger point the fault.

what is tha connected load (approx? is it matching with the 12KW or 625KW?)

I assume it is even less than 12KW (Home)

Frankly never encountered this type of problem, but still there are some things drastically wrong and the most important is the 40VAC on the ground wire. It is not important whether it is on junction box or at home.

The supply to home is 3 phase (4 wire) with floating neutral ?

The shattering of the bulbs mean extremely high over voltage and that may be resulting in leakege currents around. Do you have ELCB in the circuit? if not put it immediately this will take care of one aspect. And tripping of it will immediately pinpoint the cause.

How is the grid frequency and spike behaviour? Any sort of controlling these ? Your halogen lamps are exploding but what about electronic instruments and mechanical ones (eg fridge AC etc?)

More information may help us to guess more .

Hi

The connected load amperage on #2 phase moves all over between 12 to over 50 amps.

There seems to be no logdic to the amperage as there are no loads going on and off.

Yes the fridge is a problem and now needs repairing. The ground meggers over 1 Meg Ohms, however ELCB breakers do not trip. There are several buildings supplied from the main panel buy underground cables on the property.

Extremely unbalanced load pattern ? still in domestic tha unbalance should not be so destructive.

Phase 2 voltage is dropping by so much (or neutral is shifting towards it) that the motors - eg fridge is drawing excess current?

is the distribution transformer OK? may be it is the culprit.

How is the secondary neutral at the transformer stage earthed?

I feel you should improve the earthing at the distribution stage that may improve the situation or the worst case the ELCB will trip.

Suggest you start by turning every thing off. Check and see if there is amperage being used by this residence. If so, find out where the problem is. Maybe some of the other tenants have tapped on to the wiring.

Hi...

These numbers make no sense. Are you talking peak demand as in 12 kilowatts or in energey consumed as in 12 kilowatt hours? There is a huge difference.

Good Morning everyone.

All of the previous comments have given us a few more things to check.

The transformer is about 300 meter down a hill.

The KW mentioned is the difference in daily meter readings taken daily at the same time, the residents daily routine doesn't change. The seals on the meter seem ok. The meter is a Mitsubishi 30/100 amp 3 phase meter. I can not ever remember a meter running fast.

We do have a 3 phase digital meter we can install in the line to check the other meter.

The Mitsubishi meter was installed by the developer!

There are 4 sub panels with underground feeds from the main panel.

We will drive a new ground rod near the drain field of the septic tank (always wet), megger the neutral if good ground the neutral.

The 35 volts on the ground is the ground that come up from the MDB at the transformer. That ground does not enter the residence but only grounds the box with the meter in it and the OPEN copper bus bars. The customer gets a tingle off of the Junction box housing the meter when opening the box to check the meter.

We will be ordering a "Dent ElitePro power anylizer to look at what is happening on the system over a period of time, but delivery is still a month away.

Agian thanks for the comments and help.

And I will bet if they pull that 40 volt ground rod they will find marks on it from arcing.

j.

We still do not have enough data...

What exactly the "12kW" and "625kW" values represent has still not been identified. Is this peak demand or consumption of power? If its peak demand, the numbers make no sense. The transformer required to deliver 625kW would be massive. Do you see such a transformer?

Please... throw a clamp-on ammeter on that ground wire out at the meter. Record the current and voltage to the neutral. Then... open all of the breakers feeding loads to your buildings and see what you get.

The voltage you see on the ground wire at the meter panel could be caused by current returning back to its source from other properties. What is the utility connection like? Are the primary and secondary neutrals tied together?

The transformer is 400 KVA 33,000 primary 220/380 secondary.

the KW I am refering to is the recorded KW usage by the watt hour meter.

At the meter location (on the road) there is a metal box with the meter and an open copper bus bar where the feed for the house is jumpered through the meter to the home. Another cable is also attached to the bus bar and continues to some where else???

Thanks

Sounds to me like you need to understand exactly what "Another cable is also attached to the bus bar and continues to some where else???" means. Are you feeding power to someone else?

The cables were installed to supply power to all sold plots of land on the site.

Only 3 of the plots are in use, of these only 1 is "occupied" the bus bar in the cabinet is only a junction for the next plot, our plot has our meter connected to this bus bar and the cable to the house connected to the meter.

Thanks

Recently resolved a similar problem for a local client- the problem turned out to be degraded insulation on internal house wiring, resulting in an intermittent ground. Replacing the wiring for that circuit solved the problem. But I still wonder how many other circuits are faulty in the house- seems the wire was sub-standard...

To identify the faulty circuit, we had to test each circuit independently until we found the one the megger says was shorted. Double check to make sure nothing is connected on the load side of the circuit that reads low insulation resistance- sometimes, these circuits have a tendency to snake all through a residence with no logic to the distribution at all. Especially bad if a lot of "after thought" additions have been made...

We have set up a time to check every circuit. We will begin by isolating each breaker to each sub panel.

We will also disconnect the main feed at the meter and meggar the wires to the main breaker in the houses MDB.

Thanks

Is this the same dealy as was on here some days ago, the one with buried splices?

j.

Excellent post - We had a similiar problem in our last house. The house was newly built and after the 2nd year all the electrical items started getting fried. We went through 3 TV's in 1 year.

We called the electric company and they checked their end and said everything was fine. So we called an electrician and likewise, they said it was all ok - "Go figure"

I was wondering if a loose ground could cause unusually high or erratic readings in voltage and demand? Anyone else every experienced or solved this or a similar problem?

ELCB trip sensing is adversely affected when the service drop uses one wire for the neutral and the earth connection (no ground bond run with the drop), and the neutral/ground bonds get compromised by corrosion etc.

The resistance of the earth itself shifts the values. Also the ELCB depends on a dedicated neutral for the protected circuit; two possibilities. CJM

Ii is better to change the Meter or lodge a compalint to electricity bord.

Regards,

Pankaj Darji

Virtually every one end-up with a good answer.But its really surprising to me, A 400 KVA transformer(about 133 KVA/phase) feeding 625 KW (between two phases thats about 310 KW/phase,even if its momentary) and why-

No MCB, ELCB tripping ?

Meter is for much less rating yet its not burning?

No power fluctuation at neighbours home?( it should be a nightmare for them)

All distributions lines are safe yet they are supposed to support only a 400KW transformer?

No fuse blown at distribution transformer?

Nothing is happening to 400 KW transformer even its feeding 625 KW?

My point is, Such a huge power can not be dissipated with out an obvious effect.

Just a clarification, the METER readings vary from 40 KW on one day to 625 KW the next day. Amperage readings some times read 12 amps than 50 amps for no apparent reason.

There are no obvious high amperages being drawn at any one time, the meter readings ate far from consistent while the owners day is consistant

The customer reads the meter religiously at 8 am every morning.

There are no neighbors, only one house is occupied.

Thanks

So how big of house is this? A 400KVA 3 phase transformer supply's it? At 240 volts to use 625 KWH in a 24 hour period would need to draw something like 108 amps non stop.

Thats a lot of energy to be dissipated some place! I don't think wire with at open spot in the insulation could realistically dump that much power into the ground with out flat out burning up.

I did some emergency work for a Friends mom a few years ago when her meter was spinning like crazy one day. They found one of the old overhead farm lines had broken and fell onto an old metal machine shed. It had burned thought the tin and welded itself to one of the metal frame sections. The whole building was basically live at 120 volts with any metal point that was physically connected to the ground actually making small arcs and puffs of steam and smoke. Being some 60 years old there was no earthing ground from the building structure to the common line or to any grounding rod that would have made it possible for the circuit breaker that feed that part of the farm to trip. It was a bad short but not bad enough to trip the 100 amp service supplying it.

To dissipate the power you are saying happened over one day there should also be some steaming and smoking going on as well if the home does not have any high energy usage devices that are active.

farang1,

Please clarify a couple things for us.

1. Is the 25/625 in kW or kWh?
2. Is the meter digital?
3. If kWh, do the progression of reads advance?
4. Is the meter digital or dial?
5. Is there a multiplier involved?
   

What I am looking for is the possibility that the homeowner is not a skilled meter reader, and that there are other factors involved, like misreading.

Regards, CJM

Not a digital meter

25/ 625 KW hours read from the meter

Dial 40 revs/kw

The read out is in KWh

I will take a photo of the meter and send it to this post.

We will purchase a 3 phase digital meter today and install it as a check meter. Not expensive $ 130.00 with output for computer recording.

Thanks

Farang1, one of your posts indicated the usage jumping up to 50 amps for no apparent reason, and 50 amps for 24 hours would be around 625 kWh.

So it is possible, and the system can handle that load. That sounds less like leakage, and more like an actual load. You mentioned a second load buss that feeds an unknown load, is it possible to clamp that buss for amps? That could solve the mystery.

I have suspected a submersible pump problem from the beginning, since you are having strange voltage readings on the earth rod at the main anyway, and I have experienced the same thing at pump sites.

Are you sure there is not a well pump? CJM

If that mystery line leaving the bus bar is on the output side of the meter and not

conected to any load or loads the property owner and intended meter customer is

responsible for, the line is well Ill stop there, and could very well be the culprit to any

loads recorded by the meter in question.

Hi Craig here halogens don't like vibration so that could be the problem? With your meter if it is the old dial type some cases i have heard they have failed so could be why power fluctuating? Hope this might be some help to you.

Cheers Craig.