Have you noticed this, and do you have a suggestion?

- I have 2x5kW Sunsynk inverters in parallel with 15kWh battery bank.

- Sometimes, watching the dials on my inverter or Solarassistant, everything seems to fluctuate wildly.

- The grid usage goes up and down, the load goes up and down, the amps going into the battery goes up and down and sometimes if we have some clouds the solar production also goes up and down.

- I was used to this normally be fairly stable with normal use like when the pool pump or geyser comes on etc, but stable in a sense that it doesn't constantly fluctuate.

- Then I realized it was because of this powerful steam iron that seems to draw power for 5-10 seconds, then it will be off for 5 seconds and so on.

- The effect of this is that the inverter has to constantly adjust for these sudden changes, and seeing everything is in balance.... solar, battery, load, grid.... it causes this. It is painful to watch.

 

My question is, are there any irons that don't do this, that you can suggest? Is it bad for our other appliances?

Or am I just being a ninny

Edited February 24, 20251 yr by gimme_power

@gimme_power,

I can be wrong here, but in my mind, modern inverters - incl. SS/Deye - are transformer less designs, and relies on high frequency conversion from DC to AC.

Your system is slightly beefier than mine, and I use a standard steam iron without issues.

Perhaps this is why they don't like and drastic change in load frequently, e.g. your steam iron. Especially during days of sunshine, one want's to use the pv to supply the load. so if the load disappears (steam iron switches off), the pv can't switch off instantly, and the energy needs to go somewhere. That somewhere is the grid. Even if you do no feed back into the grid, the inverter "dumps" that excess energy into the grid, no matter your disabled feedback setting, so for a few seconds you will see energy going into the grid. The CT coil will not prevent this, because it is also slow to react in it's measurement, so up to a few 100W of power flows (in the wrong direction!)., and the inverter pulls that back immediately to 20W (the trickle feed that allows your inverter to remain synced to the grid).

So, in my view, nothing to worry about, my system is 4 years old. But I would think in the end, an Inverter that supplies constant load with few oscillations, e.g. a geyser will probably last longer that one that has an ever changing load. 

Hopefully the real gurus can also elaborate / explain this better, so I can be better informed.!

 

Edited February 24, 20251 yr by Sidewinder

If the only inconvenience is to your eyeballs, I suggest you don't look.

 

I wouldn't worry about it, as long as you're connected to the grid that can easily supply a surge of the iron turning on, or absorb the excess PV when the iron turns off. Even if you're not connected to the grid, my guess is that you'll have sufficient surge capacity and/or cooling capacity spare in your battery and your inverters to momentarily handle the 2kW or so when your iron goes on or off, so that a dump load is probably not needed.

2 hours ago, gimme_power said:

- Then I realized it was because of this powerful steam iron that seems to draw power for 5-10 seconds, then it will be off for 5 seconds and so on.

- The effect of this is that the inverter has to constantly adjust for these sudden changes, and seeing everything is in balance.... solar, battery, load, grid.... it causes this. It is painful to watch.

My system is also prone to craziness when a steam iron is used. The iron has a thermostat in it. If you hold it to your ear (do this carefully and avoid the hot plate) or your ear to the iron, you will hear it clicking on and off.

But nothing gets damaged. It might be adding a small amount to what the meter records as consumption, and my graph for the day looks very untidy for a while. But no damage done.

Just to illustrate:

Constant Load changes when load is supplied from DC.

vs when load is supplied from Grid:

Does seem when loads smaller than 1kW, it's stable, anything bigger, when PV is supplying, it's spikey again.

Mmmm, not sure why it's not posting pictures today.

Edited February 25, 20251 yr by Sidewinder
Updated with pictures

17 hours ago, Sidewinder said:

Does seem when loads smaller than 1kW, it's stable, anything bigger, when PV is supplying, it's spikey again.

Are your inverters set to prioritise load or battery and is the iron on the essential side or the grid side?

@Kalahari Meerkat, whole house is on essentials! 

 

Fixed my previous post with pictures added for clarity.

Edited February 25, 20251 yr by Sidewinder

On 2025/02/24 at 1:16 PM, gimme_power said:

Have you noticed this, and do you have a suggestion?

- I have 2x5kW Sunsynk inverters in parallel with 15kWh battery bank.

- Sometimes, watching the dials on my inverter or Solarassistant, everything seems to fluctuate wildly.

- The grid usage goes up and down, the load goes up and down, the amps going into the battery goes up and down and sometimes if we have some clouds the solar production also goes up and down.

- I was used to this normally be fairly stable with normal use like when the pool pump or geyser comes on etc, but stable in a sense that it doesn't constantly fluctuate.

- Then I realized it was because of this powerful steam iron that seems to draw power for 5-10 seconds, then it will be off for 5 seconds and so on.

- The effect of this is that the inverter has to constantly adjust for these sudden changes, and seeing everything is in balance.... solar, battery, load, grid.... it causes this. It is painful to watch.

 

My question is, are there any irons that don't do this, that you can suggest? Is it bad for our other appliances?

Or am I just being a ninny

Had a setup like yours and now a slight improved one.
Definitely had no issues with the fluctuating load when using the iron/air fryer/hair iron/hair dryer etc.
So to quote you in your words you are being a ninny 🤣

Each appliance is drawing what they need and the inverter is supplying that need from a combo of grid/PV/battery, which is then distributed via your DB, breakers and plug points.

5 hours ago, Sidewinder said:

@Kalahari Meerkat, whole house is on essentials! 

Ok, how full is your battery when you notice the spikes? and what are you battery settings in terms of if its set up to keep the battery full, be it from grid or not?

Funny that whole house here is also on essential, but there ain't no commercial grid, so not seeing what you're seeing, which is the other thing, see what this lot will do without the commercial power present... I'm guessing your batteries are pretty much full and when you are doing the ironing thing, the MPPTs are just not quick enough to respond and thus the inverter dips into reserves, the grid...

On 2025/02/24 at 4:07 PM, Bobster. said:

 The iron has a thermostat in it. If you hold it to your ear (do this carefully and avoid the hot plate) or your ear to the iron, you will hear it clicking on and off.
 

I like the pilot light switching on and off much better. Less risk of burn marks 😀😀

13 hours ago, Scorp007 said:

I like the pilot light switching on and off much better. Less risk of burn marks 😀😀

😆

But no free earwax removal  🤣

52 minutes ago, Bobster. said:

😆

 

15 hours ago, Kalahari Meerkat said:

Ok, how full is your battery when you notice the spikes? and what are you battery settings in terms of if its set up to keep the battery full, be it from grid or not?

Funny that whole house here is also on essential, but there ain't no commercial grid, so not seeing what you're seeing, which is the other thing, see what this lot will do without the commercial power present... I'm guessing your batteries are pretty much full and when you are doing the ironing thing, the MPPTs are just not quick enough to respond and thus the inverter dips into reserves, the grid...

The Battery SOC was almost full. Look at the last graph and read from the black line (SOC). Battery setup is pretty standard, I don't allow charging from the grid, and use TOU to keep a reserve (20%) for Load Shedding. I know, it's not much, but in 4 years, we've learnt to cope with that during LS times. When no LS , we use electricity normally (i.e. no power policing)😬. 

Would like to add a 3rd battery, once I can find a good price.

4 minutes ago, Sidewinder said:

The Battery SOC was almost full.

Ok, I see now also cloudy, since the solar wasn't exactly covering itself with glory 🙂 I think you will find its less noticeable when it isn't cloudy...

The below graph is for here and now + yesterday... yesterday it became cloudy from 13:30 or so and you can see the battery even before then become jittery, due to consumption/stove etc. but a lot less charge going to the battery, once the clouds came in, since the is no grid its between the solar side and the batteries... (2 X 16 X 304Ah EVE's with 150A JK BMS each) also want to increase the battery capacity still, but 1st some more panels and a changeover of inverters...