The right inverter for battery storage and some other Qs

[Oldgreybeard]

Page 18 of manual:

 If the HYD-ES inverter is faulty, manually change the switch to position 2. Grid will supply power to critical
load

and fig 18. (top of page 19)

Yes you need a changeover (bypass) switch to enable the critical loads if the inverter fails.

I didn't pay much attention to that section as I thought it wasn't relevant given I'm not running it in UPS mode.
So, if it stops working and I want full power from the grid then only option is to fully disconnect it?

Why would the inverter failing have any effect on the grid feed to the house?

The grid doesn't stop working when there is no sun, or the house batteries run too low.

[sharpener]

Page 18 of manual:

 If the HYD-ES inverter is faulty, manually change the switch to position 2. Grid will supply power to critical
load

and fig 18. (top of page 19)

Yes you need a changeover (bypass) switch to enable the critical loads if the inverter fails.

I didn't pay much attention to that section as I thought it wasn't relevant given I'm not running it in UPS mode.
So, if it stops working and I want full power from the grid then only option is to fully disconnect it?

No, if the inverter goes down you should be OK though it would be wise to disconnect it with the much-discussed isolator.

I am surprised you don't want to use the 3kW UPS capability, in the event of a power cut this would be enough to run some lights, the freezer, a gas or oil boiler and an emergency socket for other small loads.

As has been pointed out upthread you would ideally fit this with a bypass switch so if the grid is up but the inverter is down you will be able manually to switch these circuits to the grid. Even better a relay/contactor in the new CU could do this automatically at much the same parts cost.

[ducabi]

No, if the inverter goes down you should be OK though it would be wise to disconnect it with the much-discussed isolator.

I am surprised you don't want to use the 3kW UPS capability, in the event of a power cut this would be enough to run some lights, the freezer, a gas or oil boiler and an emergency socket for other small loads.

As has been pointed out upthread you would ideally fit this with a bypass switch so if the grid is up but the inverter is down you will be able manually to switch these circuits to the grid. Even better a relay/contactor in the new CU could do this automatically at much the same parts cost.

I do want the UPS functionality but wanted to cover 1 thing at a time.
So, what do I need to be able to use UPS? Just the bypass switch + earth rod?

[sharpener]

Yes you need a changeover (bypass) switch to enable the critical loads if the inverter fails.

I didn't pay much attention to that section as I thought it wasn't relevant given I'm not running it in UPS mode.

I took this to mean what it says <I thought it wasn't relevant given I'm not running it in UPS mode>

Then you will need the earth rod, and a 30mA RCD on the output to the critical circuits because the 100mA one on the input isn't sufficient for shock protection. They need to be different to provide some level of fault discrimination.

You don't need the bypass switch (or relay), this is an option if you are worried about the inverter failing. I have manual changeover switches fitted because the whole house is on the UPS side. I might add an automatic relay for the freezer because of the remote likelihood of the inverter failing while I am on holiday.

[Moxi]

Nice and easy on the solis inverter - grid fail theres an auxiliary out which I got my sparky to connect to two outdoor IP65 sockets in the battery shed, so if the power fails I just run a brace of extension leads in through the cat flap and choc in the essential circuits ie the router and the TV for the boss and the kids.

I will consider the more sophisticated route if this power issue starts to become the norm over a few winters.

To all out there on electric alone don't forget the budget mini single ring gas burners and a pack of the aerosol can sized gas cartridges - like this

https://www.amazon.co.uk/Parkland%C2%AE ... 3788&psc=1

Link only shown as an example - we have a clone of this that we use on holiday for days out to give the kids a warm meal on the cooler days.

Mr Gus, you are normally a wiz at knowing the best price and vendor for things like this, do you have any recommendations?

Moxi

[nowty]

Nice and easy on the solis inverter - grid fail theres an auxiliary out which I got my sparky to connect to two outdoor IP65 sockets in the battery shed, so if the power fails I just run a brace of extension leads in through the cat flap and choc in the essential circuits ie the router and the TV for the boss and the kids.

Is it just me or is there something typically British about this,
"run a brace of extension leads in through the cat flap"

[Oldgreybeard]

Nice and easy on the solis inverter - grid fail theres an auxiliary out which I got my sparky to connect to two outdoor IP65 sockets in the battery shed, so if the power fails I just run a brace of extension leads in through the cat flap and choc in the essential circuits ie the router and the TV for the boss and the kids.

Is it just me or is there something typically British about this,
"run a brace of extension leads in through the cat flap"

Not a lot different to our system!

I have a second small CU right next to the main one, that just runs the essential circuits and includes the changeover contactor needed to swap from grid power to backup power for those three circuits. One of the circuits is just a radial with a handful of sockets close to the consumer unit, so if we need to run something like the TV during a power cut then I just need to run an extension lead from one of those spare sockets.

The essential circuits include the lights, and as we have some lighting circuit power outlets dotted around (the small round pin ones) I can run some low power loads from those. This arrangement was easier than trying to use one or both of the rings as a part of the backup system. Main things we want running if the power goes off are the lights, the water pump and the internet, although during the last long power cut that went down, seems there is only around an hour or so of backup power in those roadside fibre cabinets now.

[sharpener]

Nice and easy on the solis inverter - grid fail theres an auxiliary out which I got my sparky to connect to two outdoor IP65 sockets in the battery shed, so if the power fails I just run a brace of extension leads in through the cat flap and choc in the essential circuits ie the router and the TV for the boss and the kids.

I will consider the more sophisticated route if this power issue starts to become the norm over a few winters.

To all out there on electric alone don't forget the budget mini single ring gas burners and a pack of the aerosol can sized gas cartridges

We experience several power cuts a year, mostly they are a few mins in the morning and again in afternoon while WPD are repairing cables or making new connections, and we get warning of them.

So it wouldn't be worth doing the wires through the cat flap stuff, take too long, fortunately the Victron switchover is seamless anyway.

Nor would it address the return from holiday, freezer full of rotting/re-frozen food scenario. Unfortunately I have no spare ways where I can install a DIN-rail-mounted contactor for automatic failover and virtually no panel space for another box.

In extremis we have my grandmother's old oil lamp, a full tank of kero and an Aga. This will save us a lot of battery capacity in the winter as cooking accounts for maybe 1/4 of daytime usage.

[Caesium]

Do you use double pole changeover switches for this, or just switch the live?

Just thinking I should do this on my UPS consumer unit.. and get that earth rod

[Oldgreybeard]

Do you use double pole changeover switches for this, or just switch the live?

Just thinking I should do this on my UPS consumer unit.. and get that earth rod

I used a double pole changeover contactor, but you need to switch both poles for safety, just in case something odd happens to the incoming neutral because of the fault that has caused the power cut. Not unknown for the incoming neutral to go to a high voltage when there's a fault somewhere.