Deye 8kW specifications

[dddem]

Hello,

I am confused by the AC section of the Deye spec sheet and manual. My case use is the "basic" mode from the manual minus "on-grid home" since there is no net metering here. Therefore I want my whole house to be the "backup load". 8kW continuous and 16kW peak is comfortable for my needs. I am in the Philippines and the grid here is 230V single phase. If I interpret correctly, the manual states that I am supposed to install a 63A breaker between the grid and the inverter, and a 63A breaker between the inverter and the backup load. At 230V AC these breakers would trip at 14,490V. But the manual states that the max "peak power" is 16,000W (2x rated power) for 10 seconds. But the breakers will trip before that peak power is even reached. So what gives?

 

[sunshine_eggo]

Breakers don't instantly trip. Breakers observe a form of the following behavior:



For this particular breaker, a 2X rated current will trip in 50-200 seconds. A 3X rated current will trip in 10-30 seconds.

Generally speaking, breakers/fuses are sized for 1.25X continuous run current even when surge is known. Most surges are too short to trip the breaker unless the breaker is failing.

The unit has a 50A transfer switch and they are recommending a 63A breaker (1.25X the rated current).

 

[dddem]

Breakers don't instantly trip. Breakers observe a form of the following behavior:

View attachment 106228

For this particular breaker, a 2X rated current will trip in 50-200 seconds. A 3X rated current will trip in 10-30 seconds.

Generally speaking, breakers/fuses are sized for 1.25X continuous run current even when surge is known. Most surges are too short to trip the breaker unless the breaker is failing.

The unit has a 50A transfer switch and they are recommending a 63A breaker (1.25X the rated current).

Thank you for this, I didn't know.

One more question: according to the specs, the unit is rated for 50A continuous bypass current. So that is the max I should be pulling for an extended period of time. If I occasionally needed to pull more than that from the grid, I could wire a bypass around the inverter with a switch on it, correct?

And yet another question: the Sol-Ark is supposedly a rebranded Deye, but I see the Sol-Ark has pre-installed breakers in the wiring bay. Does Deye have no such model?

 

[dddem]

One more question: according to the specs, the unit is rated for 50A continuous bypass current. So that is the max I should be pulling for an extended period of time. If I occasionally needed to pull more than that from the grid, I could wire a bypass around the inverter with a switch on it, correct?

Ah wait, re-reading the Deye manual, I am probably better off running it with "on grid home load" and without "backup load" in "Zero Export to CT" mode then... This way any shortcoming of the inverter will be covered by the grid.

 

[dddem]

Er... still confused... In the setup of my last post, what happens to on-grid home load when the grid goes down because of an outage? Is supply to that load cut off to save the batteries and only the backup load remains powered?

How do I wire and setup this inverter so that:

1) I do not want to have to split the loads between "critical backup" and "others"

2) When the grid is up, I don't want to be limited by the 50 amps bypass power of the inverter: if I want to run my washing machine, dryer, water heater, water pumps, AC, microwave, toaster and power tools all at the same time, I'd like to be able to do so (with grid-assist of course).

3) When the grid is down, all the potential loads remain available but I I of course accept the limitations of the inverter (8kW continuous, 16kW peak) and arrange to not run them all at the same time to avoid tripping the breakers or triggering a fault.

Can I do something like the below? WARNING I DREW THIS MYSELF, THIS IS NOT FROM THE MANUAL, DO NOT TRY THIS AT HOME

 

[kid744]

When in zero export to ct mode and grid power goes down, only things attached to the load circuit are powered.
When the grid is up and the batteries charged, (depending on load priority check box) the excess solar will flow to the rest of the house to reduce grid consumption. If you configure the gen port as a smart output, this could also be on during grid outage depending on your time of use settings. It takes a while to get the hang of the time of use settings.... Still learning myself.

Kid

 

[dddem]

When in zero export to ct mode and grid power goes down, only things attached to the load circuit are powered.
When the grid is up and the batteries charged, (depending on load priority check box) the excess solar will flow to the rest of the house to reduce grid consumption. If you configure the gen port as a smart output, this could also be on during grid outage depending on your time of use settings. It takes a while to get the hang of the time of use settings.... Still learning myself.

Kid

Thanks you for confirming this. So it looks like I am back to plan A of connecting the whole house to "backup load" and having to wire a bypass around the inverter for the rare cases I might want to pull more than 50A continuous... Either that or I have to pick another inverter with better passthrough capability... Sad...

 

[XO4001]

Would it be possible to wire in a transfer switch where you feed your house loads from grid or from backup load?

 

[kid744]

@dddem This is an 8000 watt inverter. Expecting more than 50 amps continuous out of it is a bad idea.
Unless your possible whole house loads are less than or equal to that 8000 watts, you need a sub panel with the critical loads attached to the load output of the Deye. Have you done a basic load assessment?


Kid

 

[kid744]

I used a Reliance Pro Tran 510C for my sub panel. (it is a manual transfer switch for a generator) But you are on single phase it seems so you will have to find a different product. I only have 10 circuits that are on the load output of the Deye 8K. (via the 510C) Those loads are what I consider critical during a power outage. (refrigerator, fans, lights, furnace, ect)
Kid

 

[kid744]

Here is a good place to start if you are new to this stuff.
https://diysolarforum.com/resources/categories/beginners-resources.10/

Kid

 

[XO4001]

I mean like this.
When switched to backup load only power available is the capacity of the inverter.
The switch have to be big enough to carry all the load when in grid mode.

 

[kid744]

Maximum AC current passthrough for the inverter is still 50Amps.
If you need more you have to use a subpanel so you can pick which loads are backed up by the Deye and which will go off when the grid goes down.
Kid

 

[XO4001]

Maximum AC current passthrough for the inverter is still 50Amps.

Yes this is for the backup load.
When in grid assist mode the power available is the production of the inverter and the grid combined thus full power on the main panel.
When grid power fails then you still can feed the main panel with the power available from PV and batteries.

 

[dddem]

Yes this is for the backup load.
When in grid assist mode the power available is the production of the inverter and the grid combined thus full power on the main panel.
When grid power fails then you still can feed the main panel with the power available from PV and batteries.

I am in the Philippines and we have a very unreliable grid where I live, with many blackouts and voltage variations that destroy appliances. So I definitely want my entire home to be the "backup load". Now let me understand this correctly: if my whole home is "backup load" and occasionally the 8kW power of the inverter is insufficient, it will pull the extra from the grid to get to a total max of 12kW (50A) correct?

Then I can wire a manual transfer switch to bypass the inverter and get my whole home back on the grid, should the inverter fail or if I one day needed to pull more than 12kW for whatever reason.

Correct?

 

[XO4001]

Correct?

I never tried it but that's how it is described.
Also you need enough PV and or Battery to provide the 8Kw if the grid fails.
I run mine in grid assist and only switch to back up when there is no grid.
Make sure that there is no possibility to make a grid connection on the back up connection that will let the smoke out.

 

[kid744]

Not in my experience. The max AC Current pass through is 50 Amps. (continuous) You cannot exceed that.

Kid

 

[dddem]

So thinking about it a little further, I kinda wish the Deye had integrated ATSs to move the "backup load" to "on grid home" automatically whenever "backup load" wants to pull more than 50A total. This way, the 50A limitation would be gone (as long as the grid is up obviously). Once the backup load has become on grid home (or part of on grid home), the inverter could supply 8kW of backup loads needs from solar and battery, and the rest would come from the grid, without limitation.

Is there any inverter that does that? Or is that not possible for some reason and I am missing something?

edit: I realise now that it was the idea of XO4001 above. Didn't get it at first.

 

[burgerking]

Philippines and the grid here is 230V single phase

Service Voltage in PH is very localized indeed. Some parts it is 240V, while others its 220V
In Manila it is split phase L1,L2,N. In other parts it is L-N, while others it is L1-L2.
Keep this in mind. You do not want to wire up the GRID's L to Deye's PE terminal.

I am in the Philippines and we have a very unreliable grid where I live, with many blackouts and voltage variations that destroy appliances. So I definitely want my entire home to be the "backup load".

An OffGrid setup then. You will need hefty battery bank. From late afternoon to early morning (4PM to 8AM), you do not have enough SUN to harvest. You will need to have battery capable of supplying you for this duration, OR be conservative/mindful with your power consumption. Taking hot shower (consumes ~2KW) greatly tax your battery bank. I highly suggests that you replace all non-inverter appliances such as AirConditioners, Washing Machine, Refrigerators. By doing so, you greatly reduce your battery requirement: 10KWH battery packs costs ~P200K in Philippines. This translates to ~P20 per 1WH. If you can reduce load by 1KW, you can save P20,000 in battery costs; and since this is offgrid setup, you should x14 (at least) to cover 4PM to 8AM. THIS (battery) saving should be enough to entice you to replace your power hungry appliances.

I have a 560AH battery bank and my 750W night load consumes about 10% every 4 hours. If I were to use power hungry AC, I will deplete my battery 20% every 4 hours.

Likewise, A 1HP motor consumes as much as 2000W during start up. You should keep in mind that Deye 8KW will not truly power up 8000 watts of load especially inductive motor loads. You will need to keep a healthy margin to prevent croaking. Watch

Er... still confused... In the setup of my last post, what happens to on-grid home load when the grid goes down because of an outage? Is supply to that load cut off to save the batteries and only the backup load remains powered?

You will need an ATS to automatically switch from one power source to another.
How often is power outage in your area? Is this multiple occurances a day?
Do keep in mind, ATS are rated for a few thousand strikes only. Putting your house on the "LOAD" Terminal eliminates ATS need.

Finally, you will also want to charge your batteries from GRID when your battery gets depleted at night. THIS can reduce your battery bank size. You can achieve this using Time of Use system (other inverters do not have this). Something like this:

If your battery falls below 50% capacity from 1AM to 5AM, Deye will Grid Charge them to 50%. No need to grid charge to 100% as it will be morning soon and you only want enough power until Sun goes up.
The exact time, battery capacity will greatly depend on your experience - you will be tweaking this as you go along for a period of time.

You made the right choice getting DEYE. It will serve your requirement nicely!

PS. A few days ago, it was rainy and cloudy it barely charged up my batteries. I managed to harvest about 2kwh a day for 2 days. Keep this in mind. You will want more Solar Panels and Grid Charging on specific time to get you through.

 

[dddem]

Service Voltage in PH is very localized indeed. Some parts it is 240V, while others its 220V
In Manila it is split phase L1,L2,N. In other parts it is L-N, while others it is L1-L2.
Keep this in mind. You do not want to wire up the GRID's L to Deye's PE terminal.

An OffGrid setup then. You will need hefty battery bank. From late afternoon to early morning (4PM to 8AM), you do not have enough SUN to harvest. You will need to have battery capable of supplying you for this duration, OR be conservative/mindful with your power consumption. Taking hot shower (consumes ~2KW) greatly tax your battery bank. I highly suggests that you replace all non-inverter appliances such as AirConditioners, Washing Machine, Refrigerators. By doing so, you greatly reduce your battery requirement: 10KWH battery packs costs ~P200K in Philippines. This translates to ~P20 per 1WH. If you can reduce load by 1KW, you can save P20,000 in battery costs; and since this is offgrid setup, you should x14 (at least) to cover 4PM to 8AM. THIS (battery) saving should be enough to entice you to replace your power hungry appliances.

I have a 560AH battery bank and my 750W night load consumes about 10% every 4 hours. If I were to use power hungry AC, I will deplete my battery 20% every 4 hours.

Likewise, A 1HP motor consumes as much as 2000W during start up. You should keep in mind that Deye 8KW will not truly power up 8000 watts of load especially inductive motor loads. You will need to keep a healthy margin to prevent croaking. Watch

You will need an ATS to automatically switch from one power source to another.
How often is power outage in your area? Is this multiple occurances a day?
Do keep in mind, ATS are rated for a few thousand strikes only. Putting your house on the "LOAD" Terminal eliminates ATS need.

Finally, you will also want to charge your batteries from GRID when your battery gets depleted at night. THIS can reduce your battery bank size. You can achieve this using Time of Use system (other inverters do not have this). Something like this:
View attachment 106455
If your battery falls below 50% capacity from 1AM to 5AM, Deye will Grid Charge them to 50%. No need to grid charge to 100% as it will be morning soon and you only want enough power until Sun goes up.
The exact time, battery capacity will greatly depend on your experience - you will be tweaking this as you go along for a period of time.

You made the right choice getting DEYE. It will serve your requirement nicely!

PS. A few days ago, it was rainy and cloudy it barely charged up my batteries. I managed to harvest about 2kwh a day for 2 days. Keep this in mind. You will want more Solar Panels and Grid Charging on specific time to get you through.

Thank you for your insights. Might come and visit next time I am in Subic ?

We have a standby generator here (shared between the six households in our micro "subdivision"), which is manually started a few minutes after brownouts occur, so realistically I can survive as long as the battery has enough charge to cover these few minutes. My goal is more to minimise my electricity and diesel bills and protect the stuff in my house from the wild voltage variations of our lame provider. My plan is for a 30kWh battery bank. I will be importing the cells directly from China and I hope to be able to build it for less than $5k. I will squeeze as many solar panels as I can on my roof, which is another worry because I do not want it to be torn away next time there is a typhoon. My roof is wood truss + plywood + asphalt shingles and is doing OK in typhoons but I wouldn't want the panels to act like a sail and tear it away...