Automatic transfer/changeover switch

[SolarConvert]

I went ahead and did this two months ago:

Hooked up stove and oven (they didn’t have separate circuit breakers) to the aux port of my Deye, behind a changeover switch. So when there is no load shedding, the stove and oven are non-essentials, but if there is load shedding the changeover switch is flipped and they become aux loads and they can work from solar + battery.

What a massive difference. This has enhanced the relationship with the wife.

[PsyWulf]

Thats genius

[Scubadude]

1 hour ago, SolarConvert said:

Hooked up stove and oven (they didn’t have separate circuit breakers) to the aux port of my Deye, behind a changeover switch. So when there is no load shedding, the stove and oven are non-essentials, but if there is load shedding the changeover switch is flipped and they become aux loads and they can work from solar + battery.

Pics or it didnt happen ...

[SolarConvert]

On 2022/12/08 at 11:56 AM, Scubadude said:

Pics or it didnt happen ...

I didn’t want to open the inverter, DB board or trunking…

Here is a 4.5 hour load shedding session today from 08:00 until 12:30. Actually grid power didn’t come on until after 13:00, so it was out for longer than what it was meant to be out for. You can see the cooking happening on aux power between 10:00 and 11::00 in the middle of load shedding, while the rest of the time the battery was being charged from PV. At 12:00 the battery was fully charged, so the PV power went to waste.

Edited December 10, 2022 by SolarConvert

[melvin phuti]

On 2022/12/08 at 10:15 AM, SolarConvert said:

I went ahead and did this two months ago:

Hooked up stove and oven (they didn’t have separate circuit breakers) to the aux port of my Deye, behind a changeover switch. So when there is no load shedding, the stove and oven are non-essentials, but if there is load shedding the changeover switch is flipped and they become aux loads and they can work from solar + battery.

What a massive difference. This has enhanced the relationship with the wife.

@solarcovert, couldn't you just connect your non-essentials to the aux port without the switch over? I struggle to see the benefit of the switch over in this case. 

I want to do the very same thing. I'm tired of having to pull the extension cord to the bathroom for the minigeza to heat up the water when the loadshedding schedule is bad or when we have extended power outages. 

 

What I've also observed is that the deye seems to be using Eskom side when devices are spiking up the energy draw, and when the spike goes down the energy draw continues on the inverter. Would something like that be the benefit of your setup. I speak under correction on the issue of balancing out the energy spike. 

[jeddles]

redirect excess power to micro-brewery located conveniently in the garage

[LiveBootleg]

Howzit guys. Its been a while since I've been on this forum but thought I would share what I've implemented at the end and answering some of the questions that has been asked throughout this thread.

Firstly, a note on the solar system I installed. I installed 2 Growatt inverters (2 x 5kw), 9.24kw solar panels (28 x 330w) and 14kw batteries (4 x 3.5kw Pylontech). I'm usually running out of battery between 4am and 6am every day so I will be adding another 4.8kw battery soon.

I installed this in November 2020 so its been running smoothly for over 2 years now, effectively cutting down on 80% of my Eskom bill. I've got a garden flat and an office over and above the household that it needs to power. When I installed the system, Growatt was the only inverter that was supported natively by Home Assistant as an existing integration already existed (https://www.home-assistant.io/integrations/growatt_server/). Now if I had to do this again I would probably go for a SunSynk 8Kw and use something like Solar Assistant (https://solar-assistant.io/) to plug it into my Home Assistant. 

I also considered Geyserwise - they have dual elements with 2 power sources (Grid & PV). Firstly at the time I installed this - there was no integration available into Home Assistant. There has since been some Geyserwise API's released but no formal integration, some people built their own solutions by scraping from the website and others plugged in ESP8266 modules to replace the Geyserwise Wifi module but I did not choose to go down that route. 

So my main requirements are:
1. Ensure we have hot water in the mornings 5am when my wife and I shower and in the evenings when the kids bath
2. Use as little of Eskom as possible (preferably nothing) and effectively maximise the use of PV power
3. Do not use any battery capacity to heat the geyser
4. Do this in an automated way where I don't need to look at different apps every other hour to switch things on and off

Also worth noting, I had an additional spare 150l geyser (replaced the kitchen geyser with a gas geyser) and I connected it in series with the existing one. The logic behind this was that you heat both during the day with PV and when the kids bath in the evenings the hot water is displaced from the secondary geyser to the primary one and in the bathroom the water should still be warm enough the next morning when we shower. Works like charm (only in summer though) ...

Back to the question I originally posted - I went the route of installing a Hager 25A contactor (https://hager.com/intl-en/products/information/esc427-contactor-25a-2no2nc-230v); installed by an electrician of course and bought it ElectroMechanica (https://www.em.co.za/ESC427) - one for each Geyser.

The diagram basically depicts what I've got but in principle there are 4 lines:
1. Geyser 1 Grid
2. Geyser 1 PV
3. Geyser 2 Grid
4. Geyser 2 PV

The two contactors then narrow this down to the power supply to each of the two geysers. The electrician was concerned about the contactors getting warm so we installed another wifi switch to only switch the contactors on when I need to heat them up with PV. When the contactors are switched off - the supply from Eskom still works. I also still have normal 20A circuit breakers for every line - this was also just a precaution and for CoC purposes.

So this is how my setup runs today:
I have an automation on Home assistant that runs in the afternoon between 12pm and 4pm. It switches on the PV supply for both geysers, however it checks every 5mins if its still using power from the PV and in case it starts drawing from the battery (probably because its overcast outside), then switch off the PV supply and switch on the Grid supply. This ensures we've got enough hot water when the kids take a bath at night and the battery does not run out. In the morning - I run another automation at 3am which firstly checks the geyser temperature (Sonoff TH16 which is not installed inline with the geysers at all) and if the temperature is below 40 degrees - it will switch on the Grid supply to heat it up. Best case scenario is in summer when the sun is shining in the afternoon and its not too cold outside - I use no Eskom power to heat up my geysers and we've got more than enough hot water.

Todo:
The only challenge I have currently is if we have loadshedding during 3am and 5am and the water is not warm enough. I still look at the loadshedding schedule for the next day every evening and amend the morning geyser schedule to run outside of the loadshedding window. The same would apply for an overcast day and when there is loadshedding between 12 and 4 - still need to figure this out.

[SolarConvert]

On 2023/01/12 at 1:26 PM, melvin phuti said:

@solarcovert, couldn't you just connect your non-essentials to the aux port without the switch over? I struggle to see the benefit of the switch over in this case. 

I want to do the very same thing. I'm tired of having to pull the extension cord to the bathroom for the minigeza to heat up the water when the loadshedding schedule is bad or when we have extended power outages. 

 

What I've also observed is that the deye seems to be using Eskom side when devices are spiking up the energy draw, and when the spike goes down the energy draw continues on the inverter. Would something like that be the benefit of your setup. I speak under correction on the issue of balancing out the energy spike. 

You'd need a changeover switch for the aux port for the same reason that you have a changeover switch for the essentials - so that you do not need to rewire things if you need to do repairs on the inverter. If you need to take off the inverter, both the essentials changeover and the aux changeover would be on the Eskom position side.

Furthermore, I wanted to treat my oven/stove as non-essentials most of the time and only in load shedding situations where there was sufficient battery and/or solar would I treat them on an equal footing as essentials and they would start contributing to my essentials load, i.e. when the aux changeover switch is on the inverter position.

Now it can be argued that if you do have an aux changeover switch, why not leave it in the inverter position permanently? After all, there is a setting on the inverter that allows you to power the aux load permanently if there is grid power, ignoring battery/solar minimum aux settings. My response to that would be that I was not sure whether the aux load, if permanently running even when there is grid power, would contribute to the load that goes through the inverter or not. Normally non-essentials do not go through the inverter and therefore do not place the inverter under load or count towards any maximum - the non-essentials load is a passthrough. I am not sure whether the same can be said for the aux load when there is grid power. If the aux load does place the inverter under load when there is grid power, then I would be unnecessarily potentially shortening the lifespan of the inverter. Because of this uncertainty and mainly for the reason at the beginning of my post, I feel the aux changeover switch is a must.

[AlPal]

On 2022/12/08 at 7:53 AM, Bobster. said:

V to... 

 

On 2022/07/19 at 4:59 PM, Slaki said:

So if people are still struggling with this, this is what I have done.

 

Don't judge my awesome paint skills as per attached.

 

Keep in mind that I dont have an essential and non essential BD. Everything in my house runs through the inverter.

 

I bought the following:

2 x https://www.robofactory.co.za/smart-switches/167-63a-1p-smart-circuit-breaker-with-monitoring-ewelink.html

1 x https://e-glow.co.za/products/ats-toq5-63a-ac-2p-230vac-tomzn

 

On my Deye inverter, I changed the Work mode settings to "Zero export to load"

 

Ran live and neutral wires from the "grid port" on the bottom of the inverter through a smart switch into the Source B (City power) on the transfer switch

Ran live and neutral wires from the "load port" on the bottom of the inverter through a smart switch into the Source A (PV and inverter) on the transfer switch

On the bottom of the change over switch 9The load port), I wired Live and neutral to the geyser.

 

On the smart switch for Source A (the inverter), I set the timer to come on from 11:00am until 15:30pm. I will use the sun to warm up the geyser, so we will have hot water at night.

On the smart switch for Source B (City power), I set the time for the morning between 03:00 and 06:00. Here I will use Eskom to ensure the water stays warm.

 

Note: Even if the city power smart switch is on, the change over switch will automatically switch over to Source A as soon as the source A smart switch turns on. 

 

Hope this helps...

 

 

Hi Slaki,

this is a smart solution. I have been trying to come up with a similar system to manage my 2 geysers, both 150l with Geyserwise PTC 2kW elements installed.
I am trying to ensure that I use any excess power from PV  during the day, and no battery ever for the geysers, but also have grid backup for the geysers during overcast/rainy days and the morning showers when necessary. Using your base wiring, I am going to add two timers to the supply side of the geysers to ultimately control when each one can switch on and thus try to manage the load on my inverter 'smart load' port. Also I want to add the pool pump to this circuit so that it only ever uses excess solar power to run. 

MY question is, on the 8kw Deye inverter, what is the max power you can use on the Smart Load output?
I could manage the geysers timers so that they are always out of sync and thus never switch on at the same time, so the max power it would draw would be 1 geyser and the pool pump = 2800W. But If I added the second geyser it would be 4800W.

I have 16 x 540W panels

Al.