Hi all

 

I have a Kwikot Dual 600 (https://www.kwikot.com/product-category/domestic-geysers/dsg-150/) which is probably about 6 years old. I noticed that the spec sheet says it has a 3kw element but it typically draws about 6-7kw. I notice sustained high usage after everyone showers in the morning and then every few hours during the rest of the day, there are probably 15 minute spikes of easily 6-7kw. 

 

Is this normal? Should I replace the element or drop the temp on the geyser? Anyone had a similar experience and have any recommendations on how to potentially lower this if possible?

 

Regards,

Peter

Mine draws straight 3000w (displayed on a Sunsynk 8kW) upon starting. 
Check the amp draw with a clamp meter. 

On 2022/10/19 at 7:13 AM, Johandup said:

Mine draws straight 3000w (displayed on a Sunsynk 8kW) upon starting. 
Check the amp draw with a clamp meter. 

It is my efergy engage that is reporting the draw, but I will see if I can't go and buy a handheld clamp meter and put that across the geyser supply directly, thanks.

On 2022/10/19 at 5:43 AM, zedwunare said:

Hi all

 

I have a Kwikot Dual 600 (https://www.kwikot.com/product-category/domestic-geysers/dsg-150/) which is probably about 6 years old. I noticed that the spec sheet says it has a 3kw element but it typically draws about 6-7kw. I notice sustained high usage after everyone showers in the morning and then every few hours during the rest of the day, there are probably 15 minute spikes of easily 6-7kw. 

 

Is this normal? Should I replace the element or drop the temp on the geyser? Anyone had a similar experience and have any recommendations on how to potentially lower this if possible?

 

Regards,

Peter

I have my doubts that the element has an error in manufacturing to draw 7kw. This is 30A and 50% of a 60A munic supply. The sound portion of the element should have burnt open circuit if a portion was short circuiting.

Would like to hear what the clamp meter shows.

3 hours ago, zedwunare said:

It is my efergy engage that is reporting the draw, but I will see if I can't go and buy a handheld clamp meter and put that across the geyser supply directly, thanks.

Might be a silly question but is it clamped around one wire. The single  live/hot wire (and not the neutral)? Sounds like you are possibly measuring 2x the usage. Is the CT clamp the original? It is not maybe one with a different number of windings/ bough separately? 

1 hour ago, iiznh said:

Might be a silly question but is it clamped around one wire. The single  live/hot wire (and not the neutral)? Sounds like you are possibly measuring 2x the usage. Is the CT clamp the original? It is not maybe one with a different number of windings/ bough separately? 

Do you perhaps imply that it reads double due to being clamped around both the hot wire and neutral?

1 hour ago, Scorp007 said:

Do you perhaps imply that it reads double due to being clamped around both the hot wire and neutral?

Something to that effect, I know it works on the principle of Faraday's law but I do not have any clamp meters to test my theory with and to see how the the signal/voltage is sampled, processed and digitised.

8 hours ago, iiznh said:

Something to that effect, I know it works on the principle of Faraday's law but I do not have any clamp meters to test my theory with and to see how the the signal/voltage is sampled, processed and digitised.

Due to the current in the live and neutral in opposite directions the clamp meter or CT will read zero if both are used not double.

Yes - it is only clamped around one wire. The engage seems to be accurate otherwise - when my pool pump comes on (1.1kw) my consumption appears to jump up accordingly.

See the attached graph. My baseline consumption is around 900 watts during the day - in the afternoon the pool pump came up and took us to around 2000 watts.

The early morning ~06h30 to 08h00 is the geyser, so are the other spikes. Afternoon/evening was geyser + pool pump + a furious amount of cooking by my wife lol.

Edited October 21, 20223 yr by zedwunare

During your wife's cooking the usage (including 2kw of the pool pump) is about 11-13kw non-stop for over 2 hours, that is a hell of a lot of cooking.

Does this sound right or is EVERITHING maybe somehow measured double?

8 hours ago, Bert sa said:

During your wife's cooking the usage (including 2kw of the pool pump) is about 11-13kw non-stop for over 2 hours, that is a hell of a lot of cooking.

Does this sound right or is EVERITHING maybe somehow measured double?

Even the 8kW from 6.30 to 7.15 seems way too high for a geyser.  The up and down must be some other loads. The power measurement seems very weird.

15kW is over 60A?

On 2022/10/21 at 6:27 AM, Scorp007 said:

Due to the current in the live and neutral in opposite directions the clamp meter or CT will read zero if both are used not double.

Technically it is possible to clamp around the a neutral wire that happens to have current flowing in the same direction. 

It would be similar to forming a loop and putting the same ware twice through the current clamp. Grasping at straws... I know

Personally I would say that the effergy is faulty/badly calibrated (maybe has a voltage sense resistor that is off-spec).

 

My way of testing this would be to take a reading outside at the municipal meter at say 8am and again at 9am(when the geyser is running). Calc the consumption and then compare to the consumption as reported by the effergy for that hour. They should be within 5% of each other

Edited October 24, 20223 yr by iiznh

9 hours ago, iiznh said:

Technically it is possible to clamp around the a neutral wire that happens to have current flowing in the same direction. 

It would be similar to forming a loop and putting the same ware twice through the current clamp. Grasping at straws... I know

Personally I would say that the effergy is faulty/badly calibrated (maybe has a voltage sense resistor that is off-spec).

 

My way of testing this would be to take a reading outside at the municipal meter at say 8am and again at 9am(when the geyser is running). Calc the consumption and then compare to the consumption as reported by the effergy for that hour. They should be within 5% of each other

Yes in a DB it would be possible as you describe it. However if the 2 leads through the loop go to the load and both from the source to the load enters the clamp from the same side like in a cable the current in each wire is of the same magnitude but in different directions to read zero.

So yes one can get double or zero if not a cable to load. Not easy to get the 2 wires to the load through the Jaws of the clamp

So 1st rule is only 1 wire through the loop. Not aimed at you but for those that start using a clamp meter.

Check your Efergy settings in the software. Perhaps your voltage is incorrect. The Efergy measures current and then calculates power according to voltage you have given it.

Edited October 24, 20223 yr by Peter V

Willing to guess that you probably have the voltage on the Efergy set at 110V which would explain the HUGE power usage 🙂 

18 minutes ago, Sc00bs said:

Willing to guess that you probably have the voltage on the Efergy set at 110V which would explain the HUGE power usage 🙂 

Would the 14A of a 3kW element not then give 50% as in 1540W 🤔

@Scorp007 Yup, you are correct, hmmmm, no 400V setting on a Efergy, lol

 

Update : I ended up needing to replace the element and thermostat on my geyser (coincidental failure - it has worked fine since 2014 without a hiccup). 

After that, I also moved the clamp to a different area of my Eskom feed and immediately after I was seeing a draw of 3kw while the geyser was heating. It was likely clamp placement I am guessing. Thanks for the input. 

My new problem is that my efergy engage hub is just not showing as connected at all and their support team are referring me to a data queuing issue on their side which frankly quite ridiculous as I haven't been able to properly use my efergy engage for more than a week now. Oh well.

I suspect my solar install is going to be massively overkill as my estimates were based on high utilisation but I'd rather over-bake it and be less reliant on Eskom than more so.

Good that at least you are now seeing the correct draw even if you had to change the element and thermostat. 

Still puzzled how the clamp measured such a high draw. 

Thanks. Things seem a little more realistic now in terms of the morning geyser draw being a fairly constant ±3kw but I still have high spikes here and there. It could be a geyser spike timed poorly and very coincidently with a kettle brew but.. weird. Anyway, will keep tracking.

The efergy people had some application / architecture problems with data queues which stopped the app from working for a while and it still seems quite patchy. 

I feel a bit better about an 8kw inverter with about 6600 watts of panels. 

I downsized my geyser element from 3kw to 2kw recently. 
My system was struggling to feed a constant 3000w to the geyser. 
Since then the following observations:

Much easier to get 2000w together to heat the geyser.

The temperature increase is 7 degrees C per hour per kw element when heating  i.e. 14 degrees C increase in an hour for a 150l geyser.

With a geyserwise installed it is easy to manage the system. When nothing else is using power I would just start the geyser and note the temperature increase.

 

On 2022/10/24 at 10:43 PM, Sc00bs said:

Willing to guess that you probably have the voltage on the Efergy set at 110V which would explain the HUGE power usage 🙂 

BTW the settings were at 230v and have not changed. Spikes are still a bit weird. The ±3kw that just happened at the end of the graph was cooking.

1 hour ago, zedwunare said:

BTW the settings were at 230v and have not changed. Spikes are still a bit weird. The ±3kw that just happened at the end of the graph was cooking.

Thanks for the further update. Funny I had the idea some other loads could have caused the high reading before and now. Normally the geyser will have a draw over time depending on the amount of hot water used. For showers the time it takes to reheat can be short.

In this case only you can guess what other loads could cause this.