Hi

l did my own system using Mecer 5kVA, 8 mono panels 330W each panel then 2 panels in series then 4 strings in parallel. So far l have 1 Li-On battery 2.4kW. The system is also connected to eskom. 
set solar as 1st priority. 
Can l use a washing machine, l think it’s 2kW, pool pump 1kW, microwave 2.2kW and Iron 2kW on This system during load shedding during the day? Won’t use all appliances at once to avoid overloading the inverter. 
currently the socket outlets for microwave, washing machine, iron, & pool pump are direct to eskom. 
 

Can't speak for the Mecer, but with a Sunsynk 5kW, here, that's what we do, middle of the day, when the sun is shining, we run the dishware, for instance. ( 8 + 9 Poly 280W panels)

I run a 2 kW geyser and a 1 kw, pool pump plus about 500 watts of household loads at the same time during peak sun hours and nothing from the grid ( except the 20 watts )

Edited March 14, 20215 yr by Tariq

Hi  The best way to test this is to switch off the mains power during the day and put on your appliances one by one and check your inverter front panel until you reach the limit.

 

Edited March 14, 20215 yr by Peter Topp

Think you would need to be cautious with this from solely a battery point of view. Assuming that is a Pylontech it is recommended to only discharge them at 0.5c, even at 1C you can only draw 2400w max, so if you are distracted when one of those bigger ones is on and it clouds over you would be pushing the battery close to its maximum rated discharge. 

6 hours ago, Tariq said:

I run a 2 kW geyser and a 1 kw, pool pump plus about 500 watts of household loads at the same time during peak sun hours and nothing from the grid ( except the 20 watts )

So during the day the inverter is using the solar and not the battery. 

3 hours ago, Dougiedanger said:

Think you would need to be cautious with this from solely a battery point of view. Assuming that is a Pylontech it is recommended to only discharge them at 0.5c, even at 1C you can only draw 2400w max, so if you are distracted when one of those bigger ones is on and it clouds over you would be pushing the battery close to its maximum rated discharge. 

Can l get this discharge information from the battery data sheet? 

You may want to consider getting rid of the microwave in favour of a 900W unit, and the iron (1200-1400W units are available). It's what did in my own solar journey. 2000W for the washing machine is kind of acceptable considering that the vast majority of this goes to heating water, I kept mine as well as my dishwaher (2200W). Alternatives include moving towards a semi-auto which will allow for cold water washes.

My own array is over 6kWp though, and the Sunsynk blends power, so any shortfall can be made up using grid / batteries, not sure about the Mecer.

@LeeMun, yes, as long as there is enough sun, the inverter charges up the batteries in the morning and does not touch the batteries till the night.

Edited March 15, 20215 yr by Tariq

10 hours ago, LeeMun said:

So during the day the inverter is using the solar and not the battery. 

If the inverter is set to use Solar when available, it will use solar supplemented by battery power when the solar yield does not meet the demand requirements. That means if it becomes fully overcast the battery will provide most of the demand until it reaches the preset low voltage back to grid value.

10 hours ago, LeeMun said:

Can l get this discharge information from the battery data sheet? 

Yes it should be on the data sheet

Layman's 2c. You don't have to use all your appliances at full rated power during loadshedding. If needs be, a microwave can be operated at a lower to medium watt setting like 600W, and without the grill function. A washing machine can be operated at a cool temperature, on a short cycle, or at a lower spin speed than maximum. And the iron can be turned to a lower heat setting. Why replace perfectly good appliances? As said above, be careful with the rated power of the battery; be sure it can handle the power draw when solar is insufficient, because there will be partially cloudy days where your solar production fluctuates and battery kicks in. Some experimenting on pure battery supply is maybe not a bad thing, starting from lower settings to higher.

 

9 hours ago, GreenFields said:

Layman's 2c. You don't have to use all your appliances at full rated power during loadshedding. If needs be, a microwave can be operated at a lower to medium watt setting like 600W, and without the grill function. A washing machine can be operated at a cool temperature, on a short cycle, or at a lower spin speed than maximum. And the iron can be turned to a lower heat setting. Why replace perfectly good appliances? As said above, be careful with the rated power of the battery; be sure it can handle the power draw when solar is insufficient, because there will be partially cloudy days where your solar production fluctuates and battery kicks in. Some experimenting on pure battery supply is maybe not a bad thing, starting from lower settings to higher.

 

All the appliances you mention work on the basis of switching an element/magnetron on or off. Lower settings simply mean that the on period will be a smaller percentage of the time. This means that the inverter should still be capable of carrying the full load.

I can maybe add something useful here too.

Have a 4.6kW GoodWe inverter (at least full hybrid) with 2x US3000b batteries installed and the installer looked at our washing machine and dishwasher and said yeah may need to run that during the day only. Don't have panels installed yet so we only use the batteries for backup still.

Many nights we would turn on the dish washer before loadshedding start and it would be fine. Last night we turned it on while in a slot, as that is what we do before we go to bed. We almost exclusively use it in eco mode, which saves a lot of water but still use some power at about 2kW.

This is a graph showing what it looks like:

(loadshedding slot from 20:01 to 22:09 according to the alerts I set up for myself.

Aaand this is the batteries at the same time:

 

In short, as others have said, make sure you only use 1 device at a time, which means it should be ok if one other 2kW device throws in a spike. But for long running stuff, longer than the kettle boiling, only 1 device must be on at a time.

I run a 40 year old dishwasher, a tumble drier and a few other appliances during the peak of the day and often peak at between 7 and 8 kW on my Sunsynk. I know it is safe to do this on a sunny day because the batteries are rated to deliver 7 kW from my bank so they can handle the load when a cloud passes overhead. I do this during load shedding as well. However, before upgrading the battery bank I was limited to 3.5 kW, so my loads were adjusted to only peak at 3.5 kW or slightly over as the panels can handle the rest even when overcast.

 

The batteries are a crucial component in running such big loads even on clear days as all it takes to overcurrent your battery is one tiny cloud.

 

In my case, if I only had one battery I would have been limited to 1.75 kW or just a bit over so I would have had to limit my loads to max 2.5 kW.

On 2021/03/14 at 2:33 PM, LeeMun said:

Hi

l did my own system using Mecer 5kVA, 8 mono panels 330W each panel then 2 panels in series then 4 strings in parallel. So far l have 1 Li-On battery 2.4kW. The system is also connected to eskom. 
set solar as 1st priority. 
Can l use a washing machine, l think it’s 2kW, pool pump 1kW, microwave 2.2kW and Iron 2kW on This system during load shedding during the day? Won’t use all appliances at once to avoid overloading the inverter. 
currently the socket outlets for microwave, washing machine, iron, & pool pump are direct to eskom. 
 

Yes you can. If available it will use solar, then batteries, then grid. 

I am using Sunsync 5.5 KW and I have my dishwasher and washing machine running through the inverter and the microwave on the grid. During the day, some of my production goes towards the load thats not on the inverter and at night i use battery for inverter stuff till my battery reach the set %. 

Hi @Paul Greeff, I only have two Pylontech 2000’s, but never had the problem you describe, it just blends from the grid, only time I had the over current issue was during load shedding AND an overcast day, a high current load was turned on, the inverter switched off but once the load was gone, it switched on again.

14 hours ago, Tariq said:

Hi @Paul Greeff, I only have two Pylontech 2000’s, but never had the problem you describe, it just blends from the grid, only time I had the over current issue was during load shedding AND an overcast day, a high current load was turned on, the inverter switched off but once the load was gone, it switched on again.

@Taruq, in your attempt to contradict my post you've pretty much confirmed what I just said. When the grid is not there, a single small cloud will overcurrent your battery and drop all power to the house. When the grid is up there is no problem.

@Paul Greeff, did not mean any disrespect, looks like I read you post wrong, thought you meant the situation occurs while grid is available AND when there is load shedding, again, my apologies.

Edited March 23, 20215 yr by Tariq

23 hours ago, Tariq said:

@Paul Greeff, did not mean any disrespect, looks like I read you post wrong, thought you meant the situation occurs while grid is available AND when there is load shedding, again, my apologies.

Thanks bud, no offense taken or meant.