Victron SmartShunt

[ShedPower]

Roof_tiles.jpegAnother question. I want to put some solar panels on my house roof (actually an extension I built), can anyone tell me what type of roof hook brackets I need for the kind of roof tiles I have. (see picture). If you can give a link to something that would be great. Many thanks.

[SunEagle]

Sounds a bit outside my limited skill set. (My main skill is cake eating, Solar is just a hobby). I’m wondering if there is a timer transfer switch out there somewhere.

There are some industrial transfer switches that include a timing device. But again quality equipment comes with a price tag. Maybe look into a single phase unit made be ASCO or some other transfer switch company.

[ShedPower]

Sounds a bit outside my limited skill set. (My main skill is cake eating, Solar is just a hobby). I’m wondering if there is a timer transfer switch out there somewhere.

[Bala]

I have a water pump on a plug in 240v timer to come on for a set period each day. But switching is also controlled by input from one of my solar charge controllers with parameters set to ensure that absorb v has been achieved and it then has a lvd point. It also has time delay to allow for v sag on start up.

Only the 240v timer and solar controller are off the shelf. I then have a 24/240 relay and a 240v contactor.

If using v as a change over setting the change over system needs have time delay to allow for voltage sa when motors start.

[SunEagle]

I’ve g on t an automatic transfer switch which would switch back to the grid anyway when the battery voltage dropped to eg 12.2v so I’m not worried about the sun being as strong one day as another; I think that base is covered. But in the evening / night I’d just like some appliances on grid. Just prefer an automated way of that happening.

You might need transfer switches for each load and a timer that activates them. Just remember that the sun goes down at different times during the year so unless you wait until it is night to run those loads your timer will have to change with the seasons.

[ShedPower]

I’ve g on t an automatic transfer switch which would switch back to the grid anyway when the battery voltage dropped to eg 12.2v so I’m not worried about the sun being as strong one day as another; I think that base is covered. But in the evening / night I’d just like some appliances on grid. Just prefer an automated way of that happening.

[SunEagle]

Another question. I want to run some appliances on solar during the day but switch back to the grid at night. Is there a way of doing that automatically with some kind of a timer or something? Thanks.

A timer is not enough. What if the sun is not out during the day when it was yesterday? I would think that if you want to run your loads while the sun is out then you would need something to tell your equipment that it can run on solar and not on the grid.

IMO that is wishful thinking and dangerous if your loads do not like intermittent sunlight to run because they will be starting and stopping a lot. I would think that you want some type of energy storage system fed by the solar panels to run your equipment which again IMO is the grid.

[ShedPower]

Another question. I want to run some appliances on solar during the day but switch back to the grid at night. Is there a way of doing that automatically with some kind of a timer or something? Thanks.

[ShedPower]

Thanks, I’ll have a look on Amazon for something.

[Bala]

I don't have mains power but I can change over to generator. I have a manual change over switch.

[ShedPower]

Question. If you have appliances running off your inverter in your house and you need to disconnect your batteries for maintenance etc. does anyone have a set up that allows you to switch over to grid power while you do this?

thanks.

[ShedPower]

Ah, that makes sense, thanks. I need to upgrade my inverter so I may change the whole system to 24v.

[SunEagle]

I’m a bit confused on this. I thought in series the volts increase but in paralelll the ah increases. So two batteries @130ah in series is still 130ah but in paralell they are 260ah. Or what am I missing?

You are correct that the Ah rating stays at 130 but with the higher voltage of 24V you calculate the same amount of watt hours;

12V x 260Ah = 3120wh
24V x 130Ah = 3120wh

So technically you will not need more batteries to generate the same amount of power.

[ShedPower]

I’m a bit confused on this. I thought in series the volts increase but in paralelll the ah increases. So two batteries @130ah in series is still 130ah but in paralell they are 260ah. Or what am I missing?

[Bala]

Two batteries in parallel @ 12v have the same capacity if they are in series @ 24v. Ohms law.

Higher voltage on the DC side is not necessarily safer as such but allows you use smaller cable. 48v is better than 24v. Depends what your endgame is.

The AC Side still has the same danger. If you have a fixed system like a house the you can have RCDs fitted the same as for mains.

For mobile systems there are Rvd units available.

Depends how safe you want. My house 24v system had Rcds for the Ac, my caravan and Ute 12v systems don't have Ac protection. I rarely use ac in those so it is a risk I take.