Hi All

I had a company do the installation at my property a month ago, I am not an electrician and do want some advice as whats happening because the installer is saying this is normal. I thought everything was fine until I hit the month mark when I heard my prepaid meter beeping its running out of units. I noticed in a month my prepaid meter has chowed through 100 units. Was strange because the inverter stated that only 23 units was purchased, and we do not run out of battery during the night.

When they did the install all my appliances was backed up and running through the inverter everything I guess is then essential load. My stove is gas and geyser is independent on its own solar system, the pump is powered through the inverter as well. We do not have any air-cons etc although my DB has breakers for them not sure why. The installer did confirm that everything is running through the inverter and assured me that anything running through there will be logged.

I immediately contact the installer and with great struggle got them out again yesterday. Seems they installed the CT clamp on the wrong place, they left, hoping that the issue was fixed. After two hours I checked the meter again and 0.2 KWH was purchased already. Contacted the installer and he said no it is normal usage for the system to power itself, its a hybrid system not an off the grid system. So I should contact him today and we will see.

Last night I checked the prepaid meter and it was running quickly, I switch off all the breakers and could see the pre-paid meter flashing indicating there is something drawing alot of power.

So today I checked again my power consumption on the inverter stated that 0.4 kwh was purchased where in fact my pre-paid meter is indicating a 7kwh purchased.

Is this normal for an inverter to use 7kwh a day just to power itself? I know there is that 20w Zero export to CT function but 7kwh is more than 20w.

Please see attached the inverter stated usage and load of yesterday.

Thanks

Edited January 13, 20223 yr by Guthrum

@Guthrum, what inverter is this

@Tariq Its a Deye 5kw Hybrid Inverter

Some grid usage is normal even for a perfectly set up system. 100 units in 30 days is virtually nothing and I wouldnt loose sleep over it. Couple if things to check:

- CT coil correctly installed before any loads

- All loads on inveter OR inverter set so export to load only

- Zero export trickle set to a nominal value (20W) to prevent being charged for power fed into the grid - i suspect yours is set a little higher

- Peak demand that exceeds inverter capacity

What is a little strange is the gap between production and consumption on your chart ..

@Guthrum,sorry, missed where you mentioned Deye in the subject line, summer time I use less than 30 units a month. my pv production is close to 750 units per  month.

@Scubadude is right you don't have much pv production, what sort of a day was this, cloudy, rain, etc, also what size are your solar panels

Just noticed something else ... my house has a "heart beat" through the night as fridges switch on an off ... yours is completely flat.  I suspect one or more of your kitchen circuits are before the inverter, before the CT coil even.

  

@Scubadude, you got a keen eye, 😀😄

@Scubadude I agree its not much its just strange that the inverter is not correctly stating the usage, as I am not sure where the power is going as the inverter only stated 0.4 purchased yesterday. I attached the current export to load function setup.

The production on the app graph is a little weird, It does seem that when the battery reaches a 100% it does not show the production on the graph. On the inverter you can see that mid day its pulling 3.0 but on the graph it only shows some margin around the consumption only.

Not sure about the CT clamp they moved it from the inverter to the main box yesterday, initial it was on Zero Export to Load.

They assured me yesterday that all loads are on the inverter. I have to save some units switched off the mains and only ran on battery for 2-3 days.

Peak demand as its only me and my wife we try to control very well what we are using such as after sundown switch everything off what we can computers, we also do not use two high power devices at once such as dishwasher + washing machine, we also only use the mid day. 

@Tariq Yesterday was a sunny day here in Cape Town so not really any clouds. The usage is what I was hoping for.

8 minutes ago, Scubadude said:

Just noticed something else ... my house has a "heart beat" through the night as fridges switch on an off ... yours is completely flat.  I suspect one or more of your kitchen circuits are before the inverter, before the CT coil even.

  

Thats very weird yes, just looked on my history before yesterday it was like that it seems

I would say the kitchen bypass likely happens a lot with 5kw and smaller inverters, simply because its quick peaks of power.

anyway, here's mine, the fridge heartbeat.

A quick and easy test could just be to switch the mains off, leave the inverter on and see what still works.

Edited January 13, 20223 yr by Nitrious

@Scubadude @Nitrious When I saw the light blinking on the meter late yesterday afternoon I switched off all breakers and checked the light was still going.

 

16 minutes ago, Nitrious said:

I would say the kitchen bypass likely happens a lot with 5kw and smaller inverters, simply because its quick peaks of power.

anyway, here's mine, the fridge heartbeat.

A quick and easy test could just be to switch the mains off, leave the inverter on and see what still works.

I switched off the mains now to only run on the inverter seems all the appliances are still running the AC light on the inverter is off.

maybe leave the mains off for a while if possible, see if anything was missed appliance wise.

otherwise its another trip out for installer with a clamp meter to see what's going on, and don't let them leave with "5 mins check and everything's ok stories", only once the mains can be left on without power draw.

@Guthrum, you mentioned that you are based in Cape Town, if you don't come right, maybe I could come out and help you.

1 hour ago, Guthrum said:

@Scubadude @Nitrious When I saw the light blinking on the meter late yesterday afternoon I switched off all breakers and checked the light was still going.

 

Your prepaid is still on, so it is not going through a circuit breaker ... Same may apply to other loads. Switch off the main switch and check again if your fridge, stove, microwave is working. If you have fewer than 10 thumbs take off the DB board cover and post a picture.

Something worries me - you dropped all the breakers but the house is still consuming power. I would check with the COC electrician if that is correct (read safe, legal). My breakers are after the switchover panel and inverter, so when I drop a breaker all energy to that circuit is solated and I can work on it without being electrocuted. This is not the case in your installation.

Edited January 13, 20223 yr by Scubadude

@Nitrious Thank you I will try this tonight again.

@Tariq Thank you will get another installer out today and if no luck will keep in mind thank you very much

Tbh, it seems very very dubious on the electrical side, perhaps your video doesn't show everything though. 

However it is the installer/electricians responsibility to resolve it. 

You may want/have to get a second opinion in with a report. 

maybe post some pics on the installation including the inverter and its db board. its possible if corners were cut on one side, they've been cut elsewhere.

not news anyone wants to hear, but best it all gets resolved now and quickly.

Edited January 13, 20223 yr by Nitrious

@Scubadude That's very concerning spoke to the electrician about that video and he said:  "As long as Power is  flowing through the meter, it will runs , even if you switch the house off." the other electrician that was here said something is still drawing power. I said I agree and don't no why that it everything is off, he then continued to say: "It could be the way your house is wired as its part of a complex" Not sure what the last part means if I am paying for something in the complex does not make sense to me.

I requested a copy of the COC certificate and contact detail of him to find out. Yesterday they tested to see if everything is on the inverter they realized that when not on Eskom just on inverter the trip test failed on the plugs.

I pulled off the plate last night to look where they moved the CT to here is an image

 

 

Edited January 13, 20223 yr by Guthrum

@Guthrum,

Just to check, have you set the "work mode time" page up?. It's the one where you specify start and end time with %SOC. The first few days after my 8kw Sunsynk install, it also was chowing grid, and by finetuning this, i have it down to 0.3kw per day, if not overcast. I have the  "fridge" squarewave during the night, running off batteries, but once or so, i run on grid during the night, if SOC is too low at a certain time at night - just to protect the battery, so after a few months, i'm still tweaking... 

Thanks @Sidewinder, Currently it is ticked but no times are setup as at this moment in summer I don't drain the battery during the night lowest usually is around 40% before I get more sun. Winter will be different ball game I would think.

 

Edited January 21, 20223 yr by Guthrum

Received a new update from Deye regarding my issue. Using a clamp meter showed usage around 230w to 350w usage with all breakers off just with inverter connected they explained this was the reactive power and should not billed by the prepaid. But for some reason my prepaid meter also thought it was power I am buying, for month now I switched off the grid during the day, on Tuesday I received an firmware update on the inverter from Deye the version number:

HMI: 0000-c358

Main: 3373-0513

Now it's only pulling around 50w to 80w although more than the 20w configured, its alot better than paying for a 230w-350w.