Deye: ATS or no need?

burgerking said:

For all intents and purposes, this is the wiring when I refer to not using ATS. It is becoming popular locally wherein installer relies solely on the internal relays to act as ATS. Bonus, the CT coil is installed inside Deye for a very neat install.
View attachment 108137
If power usage is within inverter's capacity, house attains zero grid consumption. If house exceeds inverter's capacity, Grid current will bypass the internal relays and into House. If PV/Battery are out, House will draw all the power from Grid, could be 10A, could be 200A bypassing the internal relays. If Installer use the recommended 40A LOAD MCB, House can easily trip this on a regular basis. If installer use the House rated 100A, it will burn the bypass relays. In case there need work be done on Deye, the whole house will go offline.

I am currently wired using an external ATS.
View attachment 108143
When Grid is up, everything is normal. Deye will generate the needed power to match whole house and I attain zero grid consumption. In case house consumes more power than what the Inverter can generate, house draws current from grid directly. There is no bypass current at any given time.

During a Grid failure, ATS switches the House to LOAD. If house exceeds Deye's capacity, the 40A LOAD MCB trips, inverter is safe, House is safe. Occupants need to turn off excess appliances and restart the MCB to resume.

Once Grid returns, ATS switches House back to GRID. Everything resumes as normal.

Lastly, I can turn off the LOAD and GRID MCBs and everything still works just fine. I can also disable the ATS and it becomes a simple DPDT switch.

Click to expand...

Isn't the only connection from the inverter output in the DEYE to the grid terminals via the bypass/pass through relay? So the house load is always passing through that relay with the exception that load higher than the export mode is set to doesn't. But I do see this setup as an advantage. Upon sensing loss of the grid the relay will open, shouldn't be any load unless you only lost one leg (I'm used to working on 3 phase power so I'd say you single phased). The house ATS transfers the load to the inverter LOAD port. Upon restoration of the grid the DEYE would then have to sync to it (adjust phase angle and voltage) and close the relay. How long does it take to do that, what is the minimum reconnection time on the grid setting screen? The ATS would need a retransfer time longer than the DEYE requires so that it absorbs the contact erosion on load transfer and not the bypass/pass through relay.

Does this imply that either the bypass relay is always connected (when the grid is good and reconnection timer expired) or that there is a separate inverter output connected to the grid terminals? If the only connection is via the relay then don't turn it on and you can't export. I'm talking about the internal logic.
Zero Export To Load: Hybrid inverter will only provide power to the backup load connected. The hybrid
inverter will neither provide power to the home load nor sell power to grid. The built-in CT will detect
power flowing back to the grid and will reduce the power of the inverter only to supply the local load and
charge the ba?ery.

DEYE should just call the home load grid connected load.

Zero Export To CT:
Hybrid inverter will not only provide power to the backup load connected but also give
power to the home load connected. If PV power and ba?ery power is insufficient, it will take grid energy
as supplement. The hybrid inverter will not sell power to grid. In this mode, a CT is needed. The installa?on
method of the CT please refer to chapter 3.6 CT Connec?on. The external CT will detect power flowing back
to the grid and will reduce the power of the inverter only to supply the local load, charge ba?ery and home
load.

dddem said:

Thank you for this, this starts to provide a good answer to my question. When you performed your measurements, which mode were you in? Zero export to load or zero export to CT?

Click to expand...

Zero export to CT.

dddem said:

So effectively, according to what you are saying, "backup load" and "home load" are merged in normal circumstances when the grid is up. If running in "zero export to CT" mode, both the backup load and the home load are fed in parallel by the inverter and the grid. When the grid goes down, the inverter disconnects from the grid and only "backup load" continues to be supplied by the inverter. All this makes sense.

Click to expand...

Correct on all points.

dddem said:

But then if "backup load" and "home load" are also merged in "zero export to load" mode when the grid is up, then it would mean that only the grid provides power to both the home load and backup load? Could you confirm that with your measurements / observing the pull from the grid at the CT? I am asking because of what the manual says:

Click to expand...

I just did this test:
Set Deye in Zero Export To Load, let it run for a minute (to ensure unit is indeed in Zero Export To Load)
Measures GRID and LOAD continuity: they are connected
Measures LOAD voltage = same as GRID's as expected.
Deye displays it was not taking power from Battery/Solar.
Unfortunately, I could not measure current flow from Deye to GRID. The wires here are too tight to get the clamp meter around a single wire. That would be definitive if it was indeed not exporting to GRID/House Load. Maybe next time I'd measure it from the main disconnect box outside - it was rainy out here.
It seems to be doing what Manual says. It is connected, but limits the power such that it is not exporting to Grid.

dddem said:

Could you recommend which ATS I should get to do that, without having to mod the ATS like you had to do?

Click to expand...

There are currently 2 kings of ATS out in the PH market namely: Rotary and Rapid Transfer

burgerking said:

Zero export to CT.


Correct on all points.


I just did this test:
Set Deye in Zero Export To Load, let it run for a minute (to ensure unit is indeed in Zero Export To Load)
Measures GRID and LOAD continuity: they are connected
Measures LOAD voltage = same as GRID's as expected.
Deye displays it was not taking power from Battery/Solar.
Unfortunately, I could not measure current flow from Deye to GRID. The wires here are too tight to get the clamp meter around a single wire. That would be definitive if it was indeed not exporting to GRID/House Load. Maybe next time I'd measure it from the main disconnect box outside - it was rainy out here.
It seems to be doing what Manual says. It is connected, but limits the power such that it is not exporting to Grid.


There are currently 2 kings of ATS out in the PH market namely: Rotary and Rapid Transfer

Click to expand...

Looks like maybe one thing you are loosing with an external ATS is the inverter disconnecting the backup load from the grid when the grid quality becomes out of spec (voltage and/or frequency variations - we have lots of these in Mindoro from our lame provider).

Do you know of any smarter ATS that could do that job? This maybe?

pilotdrh said:

Isn't the only connection from the inverter output in the DEYE to the grid terminals via the bypass/pass through relay? So the house load is always passing through that relay with the exception that load higher than the export mode is set to doesn't.

Click to expand...

If wiring with ATS, ie, the one on the manual, then YES. House load gets all power from Deye through these internal relays. BUT when there is an excessive power draw, Deye is limited only to it's maximum power and the Internal Relays is subjected only to this "limited current".

Whereas if the house was connected using internal Relays as ATS (ie the one becoming very popular, but not as instructed in the manual), excessive current will flow through these internal relays.

pilotdrh said:

Upon restoration of the grid the DEYE would then have to sync to it (adjust phase angle and voltage) and close the relay. How long does it take to do that, what is the minimum reconnection time on the grid setting screen? The ATS would need a retransfer time longer than the DEYE requires so that it absorbs the contact erosion on load transfer and not the bypass/pass through relay.

Click to expand...

Deye's Relays resume after the configured Reconnection Time on the Grid Setting - it should be able to SYNC with Grid within this time.
Likewise it would be advantageous for external ATS to use Deye's ATS240V signal to sync the transfer as well. This is why I will be remodifying my ATS to take advantage of this ATS240V signal. I will need 1 hour of rainless afternoon to do this.

pilotdrh said:

Does this imply that either the bypass relay is always connected (when the grid is good and reconnection timer expired) or that there is a separate inverter output connected to the grid terminals?

Click to expand...

LOAD connects to GRID after the specified "Reconnection Time". And from my understanding I believe there is only one Inverter module delivering only a single output shared between LOAD and GRID.

We need someone who repairs DEYE boards to confirm if there are multiple Inverter Modules on a single phase Deye inverter.


From a test done a few hours ago, I can conclude that even when Zero Export To Load Deye still connects GRID to LOAD and both shares the same inverter output. It was written in the Manual that Deye has another built-in CT that detects power flow when in Zero Export to Load. Thus Inverter maintains power solely to LOAD without exporting to GRID terminal.. Hmmm I never thought there was another CT COIL.

burgerking said:

If wiring with ATS, ie, the one on the manual, then YES. House load gets all power from Deye through these internal relays. BUT when there is an excessive power draw, Deye is limited only to it's maximum power and the Internal Relays is subjected only to this "limited current".

Whereas if the house was connected using internal Relays as ATS (ie the one becoming very popular, but not as instructed in the manual), excessive current will flow through these internal relays.


Deye's Relays resume after the configured Reconnection Time on the Grid Setting - it should be able to SYNC with Grid within this time.
Likewise it would be advantageous for external ATS to use Deye's ATS240V signal to sync the transfer as well. This is why I will be remodifying my ATS to take advantage of this ATS240V signal. I will need 1 hour of rainless afternoon to do this.

LOAD connects to GRID after the specified "Reconnection Time". And from my understanding I believe there is only one Inverter module delivering only a single output shared between LOAD and GRID.

We need someone who repairs DEYE boards to confirm if there are multiple Inverter Modules on a single phase Deye inverter.


From a test done a few hours ago, I can conclude that even when Zero Export To Load Deye still connects GRID to LOAD and both shares the same inverter output. It was written in the Manual that Deye has another built-in CT that detects power flow when in Zero Export to Load. Thus Inverter maintains power solely to LOAD without exporting to GRID terminal.. Hmmm I never thought there was another CT COIL.

Click to expand...

Yes, it seems it would have saved some money not to include the built in CT if it is only used in zero export to load, just modify the logic to not tie the inverter to the grid in that mode....not much chance of exporting then. So far I haven't found out any timer info on the Tomzn ATSs. But I was wondering why they say not to use the ones that have the grid/gen graphic on them for inverters, whereas the ones that have the solar/grid on them seem to be the same. I ordered the gen one from Lazada and a solar one from Alibaba. I'm just interested in seeing if I can find a difference. I requested a price for the Kutai BTB....probably pricey.

dddem said:

Looks like maybe one thing you are loosing with an external ATS is the inverter disconnecting the backup load from the grid when the grid quality becomes out of spec (voltage and/or frequency variations - we have lots of these in Mindoro from our lame provider).

Click to expand...

TRUE! Very true for the Rotary ATS and still true for the rapid transfer ATS.

The rapid transfer external ATS I use is not Mission Critical Rated and will glitch Computer Servers. This is because this ATS uses two Solenoids for making the transfer: First Solenoid is the small DPDT Relay that is used to power the bigger Solenoid that pulls the arm against a heavy spring.

This Kutai maybe too much IMO and is slow reaction. You will get a lot of transfer glitches.

If you are willing to modify an ATS, you could rewire it to take advantage of Deye's ATS240V signal to sync ATS transfer.

burgerking said:

TRUE! Very true for the Rotary ATS and still true for the rapid transfer ATS.

The rapid transfer external ATS I use is not Mission Critical Rated and will glitch Computer Servers. This is because this ATS uses two Solenoids for making the transfer: First Solenoid is the small DPDT Relay that is used to power the bigger Solenoid that pulls the arm against a heavy spring.

This Kutai maybe too much IMO and is slow reaction. You will get a lot of transfer glitches.

If you are willing to modify an ATS, you could rewire it to take advantage of Deye's ATS240V signal to sync ATS transfer.

Click to expand...

I don't have any problem with rewiring an ATS. I retired from ASCO last year, worked on many an ATS in my years, 30 amps up to 4000 amps.

pilotdrh said:

just modify the logic to not tie the inverter to the grid in that mode.

Click to expand...

Ditto..

I was thinking that they even include the logic for people with lousy Grid provider and use the GRID to solely Grid Charge the Battery.
I heard that some where in PH they even have utility that fluctuates from 180 to 260 on an hourly basis? That is not acceptable to feed into GRID.

pilotdrh said:

o far I haven't found out any timer info on the Tomzn ATSs

Click to expand...

This ATS will reconnect HOUSE to SourceA (Normal) ~5seconds.
But is almost instant when connecting HOUSE to SourceB (Emergency).

pilotdrh said:

But I was wondering why they say not to use the ones that have the grid/gen graphic on them for inverters, whereas the ones that have the solar/grid on them seem to be the same. I ordered the gen one from Lazada and a solar one from Alibaba.

Click to expand...

The difference between these two types is that:

The one with Solar:
It will transfer ONLY when SourceB is available. It will not work without it. This is why it is being sold at a discount in some Shopee/Lazada shops - because no one wants it. You will soon learn once you received yours. Honestly, my importer even posted in the local FB group a reward to anyone who can make it work without SourceB. No taker. He gave me one for free because it wont work without modification.

This was his modification to the ATS. I did not like it because of the lousy solder.
I replaced everything with a simpler Time Delay Relay...

The one for "Generator" will work for our Deye purpose just fine.


This is my Modification. I used a Time Delay Relay to provide 1s to 60s delay for the ATS to switch back to SourceA.
This functions just like the "Generator" version.

If however you want to use ATS240V signal for better sync:

This is my planned 2nd modification version using Deye's ATS240V signal to synchronize the transfer. Likewise, this version will power up the relay ONLY when there is a grid outage. under normal condition, this relay is OFF and should be in longer service.

NOTE: The Large Solenoids have cutoff switches. These are de-energized once it pulled the ATS lever.
The small relay with base fits inside the ATS. I made it protruding outside the case so I can pull the relay out to turn ATS in manual mode.

burgerking said:

For all intents and purposes, this is the wiring when I refer to not using ATS. It is becoming popular locally wherein installer relies solely on the internal relays to act as ATS. Bonus, the CT coil is installed inside Deye for a very neat install.
View attachment 108137
If power usage is within inverter's capacity, house attains zero grid consumption. If house exceeds inverter's capacity, Grid current will bypass the internal relays and into House. If PV/Battery are out, House will draw all the power from Grid, could be 10A, could be 200A bypassing the internal relays. If Installer use the recommended 40A LOAD MCB, House can easily trip this on a regular basis. If installer use the House rated 100A, it will burn the bypass relays. In case there need work be done on Deye, the whole house will go offline.

I am currently wired using an external ATS.
View attachment 108143
When Grid is up, everything is normal. Deye will generate the needed power to match whole house and I attain zero grid consumption. In case house consumes more power than what the Inverter can generate, house draws current from grid directly. There is no bypass current at any given time.

During a Grid failure, ATS switches the House to LOAD. If house exceeds Deye's capacity, the 40A LOAD MCB trips, inverter is safe, House is safe. Occupants need to turn off excess appliances and restart the MCB to resume.

Once Grid returns, ATS switches House back to GRID. Everything resumes as normal.

Lastly, I can turn off the LOAD and GRID MCBs and everything still works just fine. I can also disable the ATS and it becomes a simple DPDT switch.

Click to expand...

really like you idea and lay-out.
will use the same once i have my Deye 12k's .
are you controlling the ATS with a control signal from the deye , or are you using the ATS voltage sensing ?
what ATS exactly are you using...
have seen so many, but it's hard to find a good one that won't break the bank

burgerking said:

Ditto..

I was thinking that they even include the logic for people with lousy Grid provider and use the GRID to solely Grid Charge the Battery.
I heard that some where in PH they even have utility that fluctuates from 180 to 260 on an hourly basis? That is not acceptable to feed into GRID.

Click to expand...

Same here, my initial plan was to have my whole house shielded from the grid by the inverter, with it bypassing enough power to supplement the inverter only when needed.

The MPP Solar units do that so I wonder now if it would not serve my needs better... Of course this would require remaining at all times within the limitations of the inverter + bypass. And I also wonder how robust the unit if frequent "bypass upon overload" transfers occur... This option is not ticked as default, so it gives me pause... Will chat the MPP reps to see what they have to say

burgerking said:

If you are willing to modify an ATS, you could rewire it to take advantage of Deye's ATS240V signal to sync ATS transfer.

Click to expand...

I am willing but I need a how-to ?

dddem said:

Same here, my initial plan was to have my whole house shielded from the grid by the inverter, with it bypassing enough power to supplement the inverter only when needed.

The MPP Solar units do that so I wonder now if it would not serve my needs better... Of course this would require remaining at all times within the limitations of the inverter + bypass. And I also wonder how robust the unit if frequent "bypass upon overload" transfers occur... This option is not ticked as default, so it gives me pause... Will chat the MPP reps to see what they have to say

Click to expand...

i can confirm the MPP/Voltronics units do this ( my 8000 max's anyway), however as they are grid assisted , any extra power not used for batteries or additional switched load goes to waste...
better send it back to grid, so will need a hybrid myself

houseofancients said:

are you controlling the ATS with a control signal from the deye , or are you using the ATS voltage sensing ?

Click to expand...

As-Is ATS are voltage sensing.

My planned (2nd) modification will use Deye's ATS240V signal to control the ATS. It should control ATS when there is a grid outage; it should also release (revert back to Grid), when Deye says so.

dddem said:

am willing but I need a how-to ?

Click to expand...

Diagram posted above.

houseofancients said:

what ATS exactly are you using...

Click to expand...

TOMZN 125A 4P ATS
(www.alibaba.com/product-detail/4P-3-Phase-4-wire-Din_1600398824537.html?spm=a2700.shop_plgr.41413.25.6bf331d4CvuRYh)

This is what I wanted:



This is what my importer got me... At first glance they look the same... but the switching characteristics are not same.


I used this because it is DIN RAIL, measures 7p MCB and fits nicely inside the main disconnect box.

burgerking said:

As-Is ATS are voltage sensing.

My planned (2nd) modification will use Deye's ATS240V signal to control the ATS. It should control ATS when there is a grid outage; it should also release (revert back to Grid), when Deye says so.


Diagram posted above.


TOMZN 125A 4P ATS
(www.alibaba.com/product-detail/4P-3-Phase-4-wire-Din_1600398824537.html?spm=a2700.shop_plgr.41413.25.6bf331d4CvuRYh)

This is what I wanted:
View attachment 108221


This is what my importer got me... At first glance they look the same... but the switching characteristics are not same.
View attachment 108220

I used this because it is DIN RAIL, measures 7p MCB and fits nicely inside the main disconnect box.

Click to expand...

i had bought the TOQ5-125/4 ( same as your top image, only difference is the 125A ( i am planning for 2 x 12kw so need a bit more amps, and never want to get close to it's max ratings)
would you know what the exact differences are ?

burgerking said:

Ditto..

I was thinking that they even include the logic for people with lousy Grid provider and use the GRID to solely Grid Charge the Battery.
I heard that some where in PH they even have utility that fluctuates from 180 to 260 on an hourly basis? That is not acceptable to feed into GRID.

This ATS will reconnect HOUSE to SourceA (Normal) ~5seconds.
But is almost instant when connecting HOUSE to SourceB (Emergency).

The difference between these two types is that:

The one with Solar:
It will transfer ONLY when SourceB is available. It will not work without it. This is why it is being sold at a discount in some Shopee/Lazada shops - because no one wants it. You will soon learn once you received yours. Honestly, my importer even posted in the local FB group a reward to anyone who can make it work without SourceB. No taker. He gave me one for free because it wont work without modification.
View attachment 108212
This was his modification to the ATS. I did not like it because of the lousy solder.
I replaced everything with a simpler Time Delay Relay...

The one for "Generator" will work for our Deye purpose just fine.

View attachment 108215
This is my Modification. I used a Time Delay Relay to provide 1s to 60s delay for the ATS to switch back to SourceA.
This functions just like the "Generator" version.

If however you want to use ATS240V signal for better sync:
View attachment 108217
This is my planned 2nd modification version using Deye's ATS240V signal to synchronize the transfer. Likewise, this version will power up the relay ONLY when there is a grid outage. under normal condition, this relay is OFF and should be in longer service.

NOTE: The Large Solenoids have cutoff switches. These are de-energized once it pulled the ATS lever.
The small relay with base fits inside the ATS. I made it protruding outside the case so I can pull the relay out to turn ATS in manual mode.

Click to expand...

According to the manual the ATS signal works opposite of this. 240 out when connected to the grid and 0 when not. I looked through my manual and I can't locate the ATS port, but if you're not using the gen start signal the ATS signal could be routed through it since it says it is a NO contact. You'd need to look into when that signals turn on and off.

Signal island mode: when the inverter connects grid,
the ATS port will output 230Vac and it is used to cuts off
Earth-Neutral(load port N line) bond via connect external
relay. When the inverter disconnects from the grid, ATS
port voltage will be 0 and the Earth-Neutral bond keeps
on.

houseofancients said:

i can confirm the MPP/Voltronics units do this ( my 8000 max's anyway), however as they are grid assisted , any extra power not used for batteries or additional switched load goes to waste...
better send it back to grid, so will need a hybrid myself

Click to expand...

There is no net metering option where I live, so it makes no difference for me. The MPP Max 8kW is also the one I have my sights on. How heavy have you been pulling on it with "bypass mode upon overload" enabled? Any issues to report?

dddem said:

There is no net metering option where I live, so it makes no difference for me. The MPP Max 8kW is also the one I have my sights on. How heavy have you been pulling on it with "bypass mode upon overload" enabled? Any issues to report?

Click to expand...

to be honest, nothing, thing has been running excellent , as long as you stay within it specs, it runs just fine

pilotdrh said:

According to the manual the ATS signal works opposite of this. 240 out when connected to the grid and 0 when not. I looked through my manual and I can't locate the ATS port, but if you're not using the gen start signal the ATS signal could be routed through it since it says it is a NO contact. You'd need to look into when that signals turn on and off.

Click to expand...

Initially I thought ATS240V signal is OFF when Grid is available, and ON when Grid is un-available.
So I went to confirm it.
ATS240V is always UP regardless if Grid is available or not. This does not look useful.

So I checked the Signal ISLAND MODE:


With Signal ISLAND MODE enabled:
ATS240V signal is ~12Vac when GRID is available. (must be floating/noise)
ATS240V signal is 230Vac when GRID is un-available.
We are back in business to using ATS240V for actuating an external ATS.
The description on the manual did not match to what just happened.

The encircled Backup Delay could very much control when to send the ATS240V signal.
0ms = instantly when Grid failed?
1000ms = 1 second after Grid failed?
Since I was testing with a voltmeter, the timing could not be ascertained. I will need an actual relay to test this.

dddem said:

There is no net metering option where I live, so it makes no difference for me. The MPP Max 8kW is also the one I have my sights on. How heavy have you been pulling on it with "bypass mode upon overload" enabled? Any issues to report?

Click to expand...

I was told Growatt SPF also can grid charge battery while isolating AC in from AC out.
I do not know if it has scheduling like Deye does though or grid charge only if Battery is <xx%.

I have heard lots of phrases for MPP. Seems like a great inverter for people with lousy power provider.

What about PowMr?

burgerking said:

Initially I thought ATS240V signal is OFF when Grid is available, and ON when Grid is un-available.
So I went to confirm it.
ATS240V is always UP regardless if Grid is available or not. This does not look useful.

So I checked the Signal ISLAND MODE:

View attachment 108352
With Signal ISLAND MODE enabled:
ATS240V signal is ~12Vac when GRID is available. (must be floating/noise)
ATS240V signal is 230Vac when GRID is un-available.
We are back in business to using ATS240V for actuating an external ATS.
The description on the manual did not match to what just happened.

The encircled Backup Delay could very much control when to send the ATS240V signal.
0ms = instantly when Grid failed?
1000ms = 1 second after Grid failed?
Since I was testing with a voltmeter, the timing could not be ascertained. I will need an actual relay to test this.

Click to expand...

Where is the ATS port?