I’d appreciate any thoughts on the following:

After recently installing an 8KW Sunsynk inverter and 5kW battery power usage of my 4KW geyser has increased significantly!

Prior to installing the inverter and battery the average daily usage of my geyser hovered around 5Kwh (May and June).

Since installing the inverter and battery the average daily usage is between 15kwh and 20kwh (last two weeks).

I have a CBI timer installed which is set to turn the geyser on between 05h00 and 07h00 and then again between 15h30 and 20h00. These settings have remained the same before and after installing the inverter and battery.

It’s worth noting that the electrician rewired my DB when installing the inverter to spilt essential from non essential loads.

Any ideas what might be causing my power usage to have increased so much? Could it have something to do with the wiring of the DB?

Any thoughts would be highly appreciated

15 hours ago, RichardvdS said:

I’d appreciate any thoughts on the following:

After recently installing an 8KW Sunsynk inverter and 5kW battery power usage of my 4KW geyser has increased significantly!

Prior to installing the inverter and battery the average daily usage of my geyser hovered around 5Kwh (May and June).

Since installing the inverter and battery the average daily usage is between 15kwh and 20kwh (last two weeks).

I have a CBI timer installed which is set to turn the geyser on between 05h00 and 07h00 and then again between 15h30 and 20h00. These settings have remained the same before and after installing the inverter and battery.

It’s worth noting that the electrician rewired my DB when installing the inverter to spilt essential from non essential loads.

Any ideas what might be causing my power usage to have increased so much? Could it have something to do with the wiring of the DB?

Any thoughts would be highly appreciated

Have you actually confirmed by using some hot water say between 07h and 14h that the geyser does not use any power. 

The inverter should not cause this 3x times higher use by the geyser if the same times on are used. 

22 hours ago, RichardvdS said:

Any ideas what might be causing my power usage to have increased so much? Could it have something to do with the wiring of the DB?

Any geyser is either on or off. Might be your timer might be your thermostat. Splitting db for non essentials and essentials will not cause extra power consumption.  Best way to check this is by putting a clamp meter on the live geyser breaker and see if there is current flow when the timer output is off and check the current consumtion in amps when it is on. Times the current by 230v to see the actual wattage consumed. 

Edited June 18, 20233 yr by TaliaB

Your inverter has a self-consumption of around 2 kWh per day and your battery cycling is not 100% efficient. This will account for some of the increased power consumption you are seeing. Do other checks as suggested elsewhere in this post.

Hi Richard

I think an error creeped in when you first measured your daily usage of your geyser.

My 3kw 150L kwikot geyser uses about 8kw per day and that is for two people.(as per astute timer)

I assume your 4kw geyser is at least 200L so surely your element will have to run more than 1h 15min to heat that up at least once.

 

A leak? Simply colder evening temperatures, geyser cooling down faster? Insufficient insulation?

Is there any increase in hot water usage that could account for a jump in electricity consumed? Guests? Domestic?

New routines that undermine the timer settings? Getting up earlier or getting home earlier, taking showers around 6am or 6pm and re-heating the water straight afterwards?

 

Some good suggestions but the OP might just check that the CBI Astute which is used before and after does indeed read close to 4kW when the geyser is on. If it does then one has to assume the readings he indicated are correct. 

The way I read his placement is that it is not due to self use of the inverter as it is not his power consumption but only the power used by the geyser. 

With low use of hot water his before 5kWh per day could be spot on. 2.5kWh for heat loss leaves 2.5kWh for heating. My daily total power used is about 10kWh so 8kWh for geyser only is high for me. 

On 2023/06/17 at 9:20 AM, RichardvdS said:

It’s worth noting that the electrician rewired my DB when installing the inverter to spilt essential from non essential loads.

Maybe your electrician wired the CBI into all the non-essential, and not only the geyser.? 🤔

Hi RichardvdS...

I have 2 x geysers...one is a 150L running a 2kw element the other is a 200L running a 4kw. I have both connected to essential load.

I also use the CBi Astute timers for both...I run them early mornings the 2kw from 03:30 - 06:00 and the 4kw from 04:00 - 06:00 which pulls from grid during those hours.

Both those geysers at that time uses between 12-14kwh...the 4kw geyser already consumes about +/- 8kwh for those 2hrs alone...

Given your times the geyser runs that consumption seems about right...how were you measuring its consumption before?
5kwh as you say you would use previously means you only ran it for 1hr 15min as Piper eluded to which given your times set on the CBi's dont add up.

On 2023/06/17 at 9:20 AM, RichardvdS said:

After recently installing an 8KW Sunsynk inverter and 5kW battery power usage of my 4KW geyser has increased significantly!

Prior to installing the inverter and battery the average daily usage of my geyser hovered around 5Kwh (May and June).

Since installing the inverter and battery the average daily usage is between 15kwh and 20kwh (last two weeks).

Hi @RichardvdS, it's unlikely that the inverter has had this effect. How did you take these measurements?

Ok... Your PV system should be able to tell you total load each day. Are you seeing 15 to 20kWh difference per day there compared to your historic municipal/Eskom bills?

Oh... Is the timer in the DB? If so, could it have been bypassed when the DB was split? Can you ask the electrician? 

Edited June 19, 20233 yr by Bobster.

Hi All,

Thank you for the useful replies. 

Out of complete desperation i ended up replacing my geyser thermostat thinking that this was perhaps faulty and not turning off once it reached  its set temperature (hence the higher than expected electricity usage). This despite having tested the original thermostat to confirm it was working correctly.

After replacing the thermostat and setting it to approx 50deg i removed all timing settings and left the geyser on. The idea being that this would inform how much power (and time) it would take to raise temperature of 200l of water from approx 20 deg to 50 deg without any influence of timing settings. I then monitored the power usage via the CBI App and could clearly see the power draw of +-4kW over the next 2 hours (or so) at which point the power reduced to 0W.  Considering the CBI controller was still "on", the water had clearly reached 50 deg and the thermostat had correctly cut power to the element. The CBI App also reported a total power usage over this period of +-8kW (as would be expected).

After further interrogation of my CBI app I have FINALLY realised the following.....

Note:

1. my CBI App has two controllers linked to it i.e. 1 for the Geyser and 1 for the Pool.
2. my DB was rewired on 09 June

When my DB was rewired in order to split loads into essential and non essential, the electrician inadvertantly switched the wiring of the two CBI controllers. Consequently the readings on the CBI Geyser App (previously pool pump) appeared to indicate an increase from 5kWh to 20kWh for the geyser. It is now clear however that the +-5kWh (prior to 09 June) is reflective of the pool pump (i.e. 0.75kW x 6hrs) and the 20kWh (after 09 June) reflects the geyser usage (4kw x +-5hrs). As these results are reporting on the same Geyser App graph it appeared that the geyser usage has increased significantly when in fact it was due to a change in wiring resulting in the geyser usage being reported alongside the pool pump values.

Similarly the CBI Pool Pump App (previously Geyser App) has reported a similar trend with readings dropping from +-20kWh (prior to 09 June) to +-5kWh (after 09 June).

Finally SOLVED!!!!!

Thanks for everyones replies.

Richard 

Thank you @RichardvdS for letting everyone know what had gone wrong in the end.