Good afternoon everyone. I am very, very new to solar! Managed to get a system up and running for 18 months but now find i need to upgrade my solis hybrid inverter. Didnt know at the time but it shuts down if the load is over 5kw. My inverter powers the whole house. I have an 8.5kw shower in a utility that is used occasionally to wash the dogs. Have to switch to grid atm to use the shower. The sunsynk 8kw hybrid says max power is 8.8kw. I found out that it can supply 8.8kw for a short period but i cant find out how short that period is. Could i realistically run a load of 8.5kw for around 15 minutes with this inverter? If not, i will have to go with the fox ess 10.5 but there is a reason why i dont particularly want to do that. Any help is greatfully received and i apologise if this is in the wrong section. Thank you.
Mx power and rated power
- Thread starter bombie
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Vigo
Solar Addict
Is this a tankless water heater?
I agree that it would be easier to change how the heater gets its power, than to buy an entirely different inverter if the existing one works well in every other way.
I agree that it would be easier to change how the heater gets its power, than to buy an entirely different inverter if the existing one works well in every other way.
Sorry, i thought i would get a notification if anyone replied! It solis 6kw hybrid. We live on an island so power is a bit hit and miss in the winter, thats why we had the inverter power the whole house rather than just essential loads. Which means we have to be careful what we have running at any one time as switching another heavy load on, like the kettle, trips the inverter. The only option is a bigger inverter. I am trying to go off grid so i just need an inverter big enough to deal with whatever we put on. So, if the sunsynk would deal with a 8.5kw electric shower, even for 10 minutes at a time, that would solve our problems.
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Again, sorry for the late reply. Its an electric shower. Its the heaviest item we have. if i can find out that the sunsynk would handle 8.5kw, i can swap the solis for that and no need to worry about overloading it. Its really my partner. She keeps forgetting that we cant have 3 heavy items on at once so keeps tripping the inverter. Its a mental block with her. She finds things like this too complicated. So i am trying to simplify the solar as much as i can.
Vigo
Solar Addict
Have you considered rewiring just that item to be powered only from the grid?
Then surely, just connected the Solis in grid-tie mode will solve all the problems, training and technical?
Hi, i can switch over to grid any time through a manual changeover. This is how we have been doing it when the shower is needed. But i want to do away with grid power completely eventually. So having something that needs grid to work puts a spanner in the works of going off grid. The obvious answer is to buy a 7.5kw shower but thats a bit depressing as this shower is only 18 months old. Put it in just before we decided on solar. I am waiting for a reply from sunsynk regarding this but i dont hold out much hope that it will be positive.
Yes, but as i said to Vigo, i am trying to go off grid. Thank you for the suggestion, though.
Thank you for all of your comments and suggestions, they are really appreciated. I think i will bite the bullet and put a lower wattage shower in then i can have the inverter i want. As i said, i am very new to solar and i am struggling with some of the terminology. Like on the fox inverter it says "max AC current 78.3A" on the AC input. I dont know if this means the inverter will draw 78.3 under certain normal operating conditions, or it means it will work up to a max of 78.3. So if your input to your building is 78.3 or over, you cant use this inverter. I am beginning to confuse myself again! Haha! You seem like a decent bunch here so no doubt you will be seeing a lot more of me. I am glad i found this site. Thanks.
Vigo
Solar Addict
So the max AC current an inverter would accept would be while it doing its maximum possible battery charging current, PLUS whatever AC loads are being powered. This can be a MUCH higher number than the actual inverter wattage since in 'ac passthrough' you are not actually limited to what the inverter is capable of, you are limited to what the passthrough is capable of, or what your grid source is capable of (whichever is lower). So it's normal for that max AC input to be a much higher number than you would expect.
For example, i have 5000w Growatt inverters. They can charge batteries at approximately 5000w (100a X ~50v) and if i remember correctly they are capable of passing through 40amps @ 240v = ~10000w. So even though it is only a 5000w inverter, it is possible for me to pass 10000w of power through it from the AC input.
For example, i have 5000w Growatt inverters. They can charge batteries at approximately 5000w (100a X ~50v) and if i remember correctly they are capable of passing through 40amps @ 240v = ~10000w. So even though it is only a 5000w inverter, it is possible for me to pass 10000w of power through it from the AC input.
De rien
...I have Solis but am grid-tied. The issue you will also need to consider is that inductive loads will draw much when they start up. Obviously not an issue with a resistive heating element in a shower, but for shower pump and fridges, freezers etc.
The inverters are generally specified to handle the rated power, but if you you are using 8.5kW of the Sunsynk's 8.8kW output for the shower, then as soon as a fridge turns on you'll trip the inverter. SWMBO won't be impressed if she's in the shower at the time and has to reset the inverter!
Personally I'd do a detailed audit of your house usage, both daily and weekly consumption and peak load demand.
As I said, I'm on-grid... there are a lot of off-gridder's on this forum who can advise better than me, but my initial thought would be to avoid having one of those instantaneous showers at all. Having a water tank (which can be heated via an immersion heater from solar) and just a pumped shower would be a better match for going off grid, IMHO.
Good morning SeaGal, decided to just do away with the shower altogether. Or change it for a 7.5kw, which is 31A. The sunsynk is capable of 34A, so i should be able to run that if nothing else is on. (the big IF!) I dont think i explained our situation very clearly, sorry for that. Our hot water for the main shower, and our CH comes from an oil boiler. This electric shower i put in a utility room just before we put solar in. Its used solely to clean the dogs. After an hour on the beach, they bring back so much sand! I was just hoping the sunsynk would power it for 10 minutes while we wash the dogs off. Now i have realised that the reason the solis is tripping is because its over current. I researched passthrough last night. From what i can make out, its not so much the kw that are tripping the solis its the current is too high. I have already written the kw load of our heavy items down for my partner. To look at whenever i am not here, to make sure she isnt going to trip the inverter. She still cant work it out though. 2 washing machines, tumble dryer, cooker, hob and a kettle. Those are the heaviest items we use on a regular basis. Never thought there would be so much to solar. It really is quite complicated. Made more so by sunsynk saying use 8mm2 cable and fox saying use 13mm2. I havent seen any of those sold in UK. They dont make T&E to those sizes, either. Obviously i will have to use 10mm2 for the sunsynk but why not just say 10mm in the manual to begin with? There must be a reason but someone like me wouldnt have a clue why. maybe you are supposed to parallel 2 x 4mm2 singles? The ridiculous reason why i am opting for the sunsynk, rather than the larger 10.5 fox (which would power everything, no problem) is because the sunsynk has a diagrammatic screen. She can just press a button and see very easily what is going on with the solar. I couldnt find a larger than 8kw that has that sort of screen.De rien
I have Solis but am grid-tied. The issue you will also need to consider is that inductive loads will draw much when they start up. Obviously not an issue with a resistive heating element in a shower, but for shower pump and fridges, freezers etc.
The inverters are generally specified to handle the rated power, but if you you are using 8.5kW of the Sunsynk's 8.8kW output for the shower, then as soon as a fridge turns on you'll trip the inverter. SWMBO won't be impressed if she's in the shower at the time and has to reset the inverter!
Personally I'd do a detailed audit of your house usage, both daily and weekly consumption and peak load demand.
As I said, I'm on-grid... there are a lot of off-gridder's on this forum who can advise better than me, but my initial thought would be to avoid having one of those instantaneous showers at all. Having a water tank (which can be heated via an immersion heater from solar) and just a pumped shower would be a better match for going off grid, IMHO.
Thank you Vigo. That actually made it a lot clearer and gave me a starting point to research passthrough in more detail. I think i have it sussed...maybe
That makes more sense - merci.. and sounds a lovely place to live - love France... is that an island on the west or south coast?
Same thing for a given voltage
W = V x I, so 5000W divided by (say) 220V is nearly 23A.We have an emonPi energy monitoring system, as well as a DIY one, that has a little display to show how much the house usage is at any given time. It's not always straightforward though, becuase the washing machine, for example, heats up using 2.5kW for about 25 minutes and then uses very little for the remaining 35 minutes of the wash cycle.
We had a smaller inverter to start with and got into the habit of pausing the tumble dryer when we wanted to boil a kettle - though, in our case that was just to avoid paying for grid electricity, rather than having the inverter trip out.
I guess they are specifying a minimum size, rather than knowing what is available in any specific country. In the UK the most common sizes are 2.5, 4, 6, 10 and 16. But yes, in my case, I have a length of underground SWA which is 4 core 4mm2 using 2 cores in parallel to give the equivalent of 8mm2.
Not ridiculous... I love the diagrammatic screen of my Solis S5 RHI and EH1P inverters - it's even prettier than the Sunsynk one
Yes, exactly as we do now. Or rather, most of the time! I have to admit that i nearly tripped it this afternoon so its not always my partner! We have the EH1P and i am obsessed with looking at the screen every time i pass it, just to see how much is generating! haha! We really should get the fox 10.5 as it would solve the problem but no lovely screen! Just found out that the rubber sheathed cable we used for the AC input, is good for 57A and its only 6mm2. The recommended breaker for AC grid is 50A. So, i should be able to keep it to feed the sunsynk. As i said, its very complicated stuff, this solar. I am glad we do not have a smart meter (by choice) so do not have to deal with power being sold back and trying to keep track of what the power company is doing with our batteries. An installer told me that certain companies empty your batteries to sell the power at peak rate then top them back up again when its cheap, usually overnight. Whether true or not, i dont know but i just assume every company is dodgy! Also, no wifi, again by choice. So no messing with phones, hoping it connects, hoping it stays connected etc. Thats why i like the screens so much as everything is done at the inverter. Comparatively, i guess our set-up is extremely simple but still very complicated when you dont know what you are doing
Your power company wouldn't be able to control the discharge or charge profile of your batteries. Obviously you may wish to export if you have high export income at certain times of day and then charge back up when it is cheap - but that would be your choice and under your control.
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