I wish Victron Phoenix ECO mode could search for longer than 5 seconds

[eemarty]

I have a farm stand and I'm running a commercial fridge in there on an off-grid solar setup. The Victron Phoenix 24/1200 runs it like a champ, but I'm trying to reduce power consumption by using ECO mode. When the fridge compressor is running it draws about 450W and when it's off it is basically 0W. When the fridge gets down to the set temperature and shuts off the compressor, it wont need to come on again for 10min or sometimes hours depending on the outside temperature. So if the inverter could power down the fridge and just check every 5 min or so to see if the compressor needs to run, it could save about 10W of idle power which could be 240Wh per day.

The problem is that the fridge doesn't turn on the compressor right away when it powers up. It waits about 7 seconds. Unfortunately ECO mode can only be set to search for 5.0s max. So ECO mode powers up the fridge for 5 seconds, doesn't sense a load and shuts back off. All before the compressor has time to kick on. Any chance Victron could update the firmware to make a 60 second search time? Also search intervals longer that 64s would be useful too. I would ideally set it to 5 minutes or so in my case. I think this would be useful for lots of folks.

Or can anyone think of another way I could get this to work? I was thinking about using a different thermostat connected to the remote port but the fridge has a programmable thermostat with lots of great features. Maybe a AC device that engages a 5W load for 20 seconds every time it powers up? Is that a thing? That would keep the search on for long enough for the compressor to start.

Here's a snippet from the Manual on ECO mode:

The inverter is equipped with ECO mode. ECO mode is activated via the VictronConnect app, the inverter main switch or push button (depending on inverter model).

When the inverter is in ECO mode, it will reduce its power consumption by approximately 85% when there are no loads connected to the inverter.

When the inverter is in ECO mode, the inverter will switch to search state when there is no load or a very low load. While in the search state, the inverter is off and will switch on every 3 seconds for a short period (adjustable). If the inverter detects a certain size load (adjustable) the inverter will go back to normal operation mode. Once the load drops below a certain level, the inverter will go back to ECO mode.

Below table indicates the default settings and setting range of the ECO parameters:

Parameter	Default value​	Range​
Wake-up power	60VA​	0VA - inverter rating​
Shutdown power	50VA​	0VA - inverter rating​
ECO mode search interval	3s​	0 - 64s​
ECO mode search time	0.16s​	0.08 - 5.00s​

 

[yodamota]

what about a light bulb that comes on when the fridge is on? Wired when the fridge tries to start or some other small load.?

I assume you tried setting the wake up minimum power to something lower?

 

[400bird]

Or can anyone think of another way I could get this to work?

What's the saying? 1000 ways to skin a cat.
Different thermostat in the fridge is one. But if you want to leave the fridge as is...

I was thinking about using a different thermostat connected to the remote port but the fridge has a programmable thermostat with lots of great features. Maybe a AC device that engages a 5W load for 20 seconds every time it powers up? Is that a thing? That would keep the search on for long enough for the compressor to start.

Yes, enough searching for the proper style of timer relay would find one. You could also use a Shelly relay. They're wifi with plenty of programming options, but you might need some external control (home assistant or something similar)

 

[eemarty]

It worked!

I designed a little circuit to turn on a 12V 5W automotive lightbulb for about 10 seconds and then switch off. I'm running this off a 120V to 12V AC-DC power supply that I had laying around. The whole circuit operates at 12V and is limited to 500mA through the power supply. I was able to scrap the capacitor and NMOS transistor from an old switching power supply that I didn't need. It successfully tricks the Victron into staying on until the fridge compressor has time to engage. Now, the Victron only wakes up every ten minutes and runs the compressor if needed to get to the programmed temperature and then goes back to sleep, exactly as I wanted.

I also discovered that in the Victron Connect android app, you can type in arbitrary values for the Wake-up power and shut down power of eco mode. So even though the plus and minus buttons move in 10VA increments, you can type in 5 or 3 for example. Also, it allowed me to set the ECO mode search interval to much longer that 64seconds. But the search time wouldn't go longer than 5.0sec.

 

[cs1234]

It worked!

I designed a little circuit to turn on a 12V 5W automotive lightbulb for about 10 seconds and then switch off. I'm running this off a 120V to 12V AC-DC power supply that I had laying around. The whole circuit operates at 12V and is limited to 500mA through the power supply. I was able to scrap the capacitor and NMOS transistor from an old switching power supply that I didn't need. It successfully tricks the Victron into staying on until the fridge compressor has time to engage. Now, the Victron only wakes up every ten minutes and runs the compressor if needed to get to the programmed temperature and then goes back to sleep, exactly as I wanted.

I also discovered that in the Victron Connect android app, you can type in arbitrary values for the Wake-up power and shut down power of eco mode. So even though the plus and minus buttons move in 10VA increments, you can type in 5 or 3 for example. Also, it allowed me to set the ECO mode search interval to much longer that 64seconds. But the search time wouldn't go longer than 5.0sec.

 

[eemarty]

If you dont want to design your own circuit to do this, they make simple modules to turn on a relay at power up and turn it off after a short time. You could use this and wire a 12V power supply and a 5W light bulb to the relay outputs.

https://www.aliexpress.us/item/3256805619489233.html