Solar PV DC Isolation Switches

[bobbybasic]

Mine failed, then I read this and ditched the switch.

Isolators for Solar Panels

Isolators for Solar Panels - an article by 12 Volt Planet. A product we get asked for a lot is 2-pole isolators for use with solar panels .. we break down the myths behind these switches and explain why they may do more harm than good

www.12voltplanet.co.uk

 

[Salty Spuds]

Its partly to do with regs, but the also for maintenance etc. Victron regs say the battery should be connected to the MPPT before the solar, and vice versa, solar disconnected from MPPT before battery. This is difficult without a switch.

Isn’t the MPPT permanently connected to the battery & fused?

 

[TallPaul_S]

Isn’t the MPPT permanently connected to the battery & fused?

Not if you have a master system isolator switch that cuts off everything from the battery, IE on the single positive cable going to the battery.

 

[The Flying Scotsman]

Mine failed, then I read this and ditched the switch.

Isolators for Solar Panels

Isolators for Solar Panels - an article by 12 Volt Planet. A product we get asked for a lot is 2-pole isolators for use with solar panels .. we break down the myths behind these switches and explain why they may do more harm than good

www.12voltplanet.co.uk

I’m in 2 minds whether to fit the one I’ve bought now

 

[Skyliner33]

I’m in 2 minds whether to fit the one I’ve bought now

I can't decide if to fit one either. There is a huge discussion on the Campervan Electrics (run by Roamer iirc) page on Faceache.

 

[Stay Frosty]

Bringing up this thread again as I am undecided about this. Do the regs for the UK not specify that a solar PV isolator switch should be fitted?

@Stay Frosty do you have a link for the switch you are using?

It's literally a domestic double pole switch that would normally isolate a 230V load like a cooker or hob.
I had indicated it was a 30A switch but having farted around with the leisure setup recently changing the AGU fuse block to a Mega and Midi fuse version I noticed the PV isolator I've used is actually a 20A switch but it hasn't gone all crunchy and burnt out inside so we're golden.
It has crossed my mind that with an isolator on the starter battery input to the Renogy DCC50S I could isolate all inputs rather than just using the LB isolator and still having a live input at the B2B... but then where do you stop noodling and simply say that'll do.

 

[Stay Frosty]

@Skyliner33 Just read that article you linked to and are they assuming a lead acid leisure battery only for myself I've used 6:00mm2 conductors and haven't got a fuse on my solar until the leisure battery under the seat.
I isolate the solar via the wardrobe switch at times when our Roamer is stuffed eg Busfest last year where the two 175 watt panels were keeping us at 100% full which probably wouldn't be good for the LB long term.

 

[Skyliner33]

@Skyliner33 Just read that article you linked to and are they assuming a lead acid leisure battery only for myself I've used 6:00mm2 conductors and haven't got a fuse on my solar until the leisure battery under the seat.
I isolate the solar via the wardrobe switch at times when our Roamer is stuffed eg Busfest last year where the two 175 watt panels were keeping us at 100% full which probably wouldn't be good for the LB long term.

I didn’t link the 12v planet article. I didn’t realise it was talking about lead acid batteries.

 

[Stay Frosty]

Sorry it was @bobbybasic

 

[The Flying Scotsman]

Sorry it was @bobbybasic

So should we fit them with a lithium set up ?

 

[Stay Frosty]

I fitted mine as if it's turned off I'm not going to short anything out and bugger it up.