# MPPTs are being switched "OFF" and "ON" every few seconds - WHY? **URL:** \ **Category:** DIY\ **Tags:** gx\_device, beginner, cerbo\_gx, victronconnect\ **Created:** [18 April 2026 10:31 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672 "2026-04-18T10:31:27Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [18 April 2026 10:31 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/1 "2026-04-18T10:31:27Z")
This behavior started about 3 weeks ago. By the time, I was running on the latest Beta VenusOS V3.80~12 The following configuration. AC1 Is set to Generator (current limit is set to 16A) AC2 is set to Grid (current limit is set to 20A = Grid circuit Breaker rating) ESS Settings ![image](https://europe1.discourse-cdn.com/victron/original/3X/e/d/ed1b4c8875d17b414afbec08f3d1062ea6434a26.png) Connected devices: ![image](https://europe1.discourse-cdn.com/victron/original/3X/2/6/264c93d99dfb90f93542fe037a4ab7a1c84dfe6f.png) Both Solar chargers have the same amount of panels. Both arrays are on the same roof side and are mounted with same angles and face the exact same direction - NO shading - NO clouds! **The problem is that the MPPTs Operating Mode are constantly switching between 0, 1 and 2** 0=Off 1=Voltage/current limited 2=MPPT active I am logging via MQTT and displaying the data with Grafana and this is how a 5 Minute graph looks like: MPP Charger Output Power and MppOperatingMode ![image](https://europe1.discourse-cdn.com/victron/original/3X/5/2/520c313904e3c152ed4b3c8f74be5187f02a42ab.png) ESS Setup is currrently ![image](https://europe1.discourse-cdn.com/victron/original/3X/2/7/2773e356b2d2ba46281c25a7842c31e3152656e8.png) ![image](https://europe1.discourse-cdn.com/victron/original/3X/e/6/e6b86f05b43360eaf1245df38667647d73dd9fa2.png) ![image](https://europe1.discourse-cdn.com/victron/original/3X/e/4/e4eab7a27b14463b5983a0f7d869ebfa94676089.png) Peak shaving is enabled because of Grid Breaker rating ( 20A) ![image](https://europe1.discourse-cdn.com/victron/original/3X/2/9/295bfbbd117708c137e3a18a08a8a9568e7bafed.png) …and I can not figure out why it does not work ☹ What I have done so far: Went numerous times through all settings, but can not find anything wrong ☹ Disconnecting the MPPTs - by pulling the VE.Direct cables and reseting BMS-Control via Victron Connect -Bluetooth Now the charger stayed ON but NO Grid Feed-in ☹ additionally I did set the "GRID SETPOINT to - 4500W THEN the grid feed-in starts working, but it is **not using the Full Solar power** ☹ …and I had to control this **by manually adjusting the grid set point** SO NO way this is going to stay like this. I even did a clean OS install. Flashed the Venus OS from SD Card and downgraded to the official V3.67 - (still the same problem here) then updated to V3.72 (this is the version currently running, but still the same problem ☹ Any idea what could cause this behavior? What else should I check? I am out of ideas. Thanks for any input ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [18 April 2026 12:52 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/2 "2026-04-18T12:52:42Z")
This is what it looks like, when the MPPTs are disconnected from the CerboGX. DC Loads \> Enabled and showing the **Solar** power as **Negativ** Power Grid set-point is -4600W. Excess Feed-in should kick in, when the EV is fully charged. ![image](https://europe1.discourse-cdn.com/victron/original/3X/0/5/05abd394c69de43ebcb2ad38aab25ee2d59fe895.png) ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [18 April 2026 13:16 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/3 "2026-04-18T13:16:57Z")
MPPTs still disconnected. EV Charger has finished and excess solar is feed into the grid. ![image](https://europe1.discourse-cdn.com/victron/original/3X/9/1/91f2ed5e704769d42a4d308097aa4b9ccf4bd0d9.png) BUT ONLY ~2500W Grid setpoint is at -4600 Is there a LIMIT for the Grid Setpoint? ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [18 April 2026 13:25 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/4 "2026-04-18T13:25:31Z")
Battery is almost full DC Loads (Solar power drops from 6KW to ~4KW) because of the Limited grid feed-in Great ☹ ![image](https://europe1.discourse-cdn.com/victron/original/3X/9/5/950aa4d8bc89ad420ffae3bd2c81b9f370efabd9.png) ---
**Author:** ![nickdb](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/nickdb/32/51440_2.png) [@nickdb](https://community.victronenergy.com/u/nickdb)\ **Post date:** [18 April 2026 14:36 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/5 "2026-04-18T14:36:42Z")
Have you installed a production version - 3.72? Betas have issues and the main forum sections aren’t intended for betas. If you have any modifications, remove them so there are no variables. If you have dess, disable that. There are just too many reasons issues like this happen, difficult to diagnose remotely. That the mppts aren’t listed is an issue, I would be checking all the wiring carefully. For multiple mppts to disappear is highly unusual, typically there is a local issue being overlooked It won’t work correctly if the mppts aren’t visible on the gx. If you connect to them with the app do they show any history of error codes? What voltage is your PV string? ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [18 April 2026 14:56 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/6 "2026-04-18T14:56:06Z")
Thanks for your input > [@Jurgen\_Pflug](#): > > I even did a clean OS install. Flashed the Venus OS from SD Card and downgraded to the official V3.67 - (still the same problem here) > then **updated to V3.72** (this is the version currently running, but still the same problem ☹ NO Modifications! ONLY Mobus TCP server enabled (used by EV charger) MQTT access enabled for Homeassistant mirroring the MQTT Broker The MPPT are NOT listed, because I DISCONNECTED them. I only get the system half way working when the MPPTs are disconnected! DESS is also OFF ![image](https://europe1.discourse-cdn.com/victron/original/3X/e/d/ed1b4c8875d17b414afbec08f3d1062ea6434a26.png) ---
**Author:** ![nickdb](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/nickdb/32/51440_2.png) [@nickdb](https://community.victronenergy.com/u/nickdb)\ **Post date:** [18 April 2026 15:16 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/7 "2026-04-18T15:16:30Z")
Disconnected they will work purely on bus voltage, exporting isn’t intended to work like that. When they are connected at least you will have data in VRM that could show why they are shutting down. What grid code are you using? Some limit exporting. ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [18 April 2026 15:41 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/8 "2026-04-18T15:41:10Z")
Maybe I did not mention it: The system worked fine until about 3 weeks ago. Grid feed-in was working!! NOW, when I connect the MPPTs, they are being switched ON and OFF (hence the title.) Grid code settings: ( Country=Namibia) ![image](https://europe1.discourse-cdn.com/victron/original/3X/8/e/8e462a0d2bfd4a885fbfc44e820cba6946ee300d.png) EXPORT is LIMITED to the Main CB Rating, 20A ![image](https://europe1.discourse-cdn.com/victron/original/3X/4/7/4797dd263ce8e7ce9bce5ff301475abd1fedf9cc.png) This should be around 4600W (230V x 20A) ---
**Author:** ![nickdb](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/nickdb/32/51440_2.png) [@nickdb](https://community.victronenergy.com/u/nickdb)\ **Post date:** [18 April 2026 15:52 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/9 "2026-04-18T15:52:28Z")
Attach your remote config file here if you can. It doesn’t contain any PI. ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [18 April 2026 15:54 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/10 "2026-04-18T15:54:09Z")
Here is the remote config file: [Doros\_Replacement\_c0619ab9fcbc\_inst\_ttyS4\_Interfaces\_Mk2\_Tunnel (4).rvsc](https://community.victronenergy.com/uploads/short-url/v1JVQ16LL0xFfNfwVbllU5xBKT7.rvsc) (5.9 KB) ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [19 April 2026 06:28 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/12 "2026-04-19T06:28:40Z")
Yesterday, after sunset, I reconnected both MPPTs back to the CerboGX. This morning, I was monitoring the system, from shortly before sunrise. Both MPPTs did NOT switch to MppOperatingMode=2 even though there is bright sunlight So I disconnected both MPPTs and disabled the BMS control. Both chargers immediately started charging ![Screenshot_20260419-081029_VictronConnect](https://europe1.discourse-cdn.com/victron/original/3X/b/3/b3f40e2fec8ef7ed786511a1116c75f9cbb1981a.jpeg) So why did the CerboGX NOT switch the MPPTs ON ??? ---
**Author:** ![ejrossouw](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/ejrossouw/32/1610_2.png) [@ejrossouw](https://community.victronenergy.com/u/ejrossouw)\ **Post date:** [19 April 2026 08:14 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/13 "2026-04-19T08:14:33Z")
@Jurgen_Pflug What changed three weeks ago? Unrelated, but why set an inverter limit of 8000W if it is only a 6400W unit? An ESS will not exceed it unlike an off-grid system that can be higher for short durations. Also, do you have AC coupled PV enabled, but I did not notice and AC inverter? Curious to note you have serious DC consumption is that correct and what DC consumer are you running? I did not notice DVCC settings in your post which should be enabled. ---
**Author:** ![nickdb](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/nickdb/32/51440_2.png) [@nickdb](https://community.victronenergy.com/u/nickdb)\ **Post date:** [19 April 2026 08:36 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/14 "2026-04-19T08:36:21Z")
Nothing obvious here apart from power assist that should be off for an ESS. ---
**Author:** ![nickdb](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/nickdb/32/51440_2.png) [@nickdb](https://community.victronenergy.com/u/nickdb)\ **Post date:** [19 April 2026 08:40 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/15 "2026-04-19T08:40:41Z")
They are on, they are producing 180W give, or take, they just aren’t ramping up. What are the BMS parameters at this time - CVL, CCL, DCL? Have you compared the voltages (using a meter) at the battery terminals, the mppt terminals and the inverter? What is the PV string voltage at this time (asked this earlier)? What are the dvcc parameters? When something works fine and then doesn’t, after no changes, it can be a poor connection somewhere that leads to voltage discrepancies, which will throw the system off. ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [19 April 2026 08:51 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/16 "2026-04-19T08:51:53Z")
> [@ejrossouw](#): > > inverter limit of 8000W if it is only a 6400W unit? The Quattro is a 48/8000 that is the inverter limit = 8000W Where do you see the 6400W? ---
**Author:** ![nickdb](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/nickdb/32/51440_2.png) [@nickdb](https://community.victronenergy.com/u/nickdb)\ **Post date:** [19 April 2026 08:55 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/17 "2026-04-19T08:55:21Z")
it is 8000VA, not Watts. Its continuous wattage rating, after power factor, is 20% less and decreases with temperature. It is a 6400W inverter as per the datasheet. Also your temps seem high - battery at 34C - the system will be derating. The battery may even be limiting charging at that high reading. ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [19 April 2026 08:55 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/18 "2026-04-19T08:55:34Z")
> [@ejrossouw](#): > > Also, do you have AC coupled PV enabled, but I did not notice and AC inverter? Curious to note you have serious DC consumption is that correct and what DC consumer are you running? NO AC Coupled PV DC Consumption is showing NEGATIV, that happens because the DISCONNECTED MPPT’s are showing supplying the system ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [19 April 2026 08:59 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/19 "2026-04-19T08:59:03Z")
> [@ejrossouw](#): > > DVCC settings in your post which should be enabled. IMPORT & EXPORT Tariffs are the same here 24/7 Enabling dvcc worked AS EXPECTED, but until I find the problem it is off for now ---
**Author:** ![Jurgen\_Pflug](https://avatars.discourse-cdn.com/v4/letter/j/3d9bf3/32.png) [@Jurgen\_Pflug](https://community.victronenergy.com/u/Jurgen_Pflug)\ **Post date:** [19 April 2026 09:01 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/20 "2026-04-19T09:01:42Z")
> [@nickdb](#): > > Nothing obvious here apart from power assist that should be off for an ESS. I can do that, but how would that effect the MPPT’s? Disabled and uploaded ![image](https://europe1.discourse-cdn.com/victron/original/3X/5/b/5b64b3d06ea9e2792948b0f821dbae5d16ca9b11.png) ---
**Author:** ![nickdb](https://dub1.discourse-cdn.com/victron/user_avatar/community.victronenergy.com/nickdb/32/51440_2.png) [@nickdb](https://community.victronenergy.com/u/nickdb)\ **Post date:** [19 April 2026 09:03 UTC](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672/21 "2026-04-19T09:03:29Z")
Anything that could affect ESS could affect how the system works. It should typically be ignored, but I like to turn off anything that should not be enabled, including feed-in AC PV, if you don’t have any. [Next page](https://community.victronenergy.com/t/mppts-are-being-switched-off-and-on-every-few-seconds-why/56672.md?page=2)