DC disconnects/isolators.

[NoraBatty]

Stinsy is right, no way i would be buying from aliexpress for such things.
i have, admittedly bought a din enclosure off of amazon to use, but i have replaced the actual breakers with those mersen fuse holders as linked, that are of a known quality. I went via cpc for them, though the fuses i got from rs that stinsy links to.
The dc disconnect was from cpc too.

As far as i am aware dc isolators are not needed and no longer recommended if the inverter has an isolating switch already.
If you were using a solar charge controller, the need for DC isolating is different.
In my case i am running wiring underground, so i am making sure the cables are fused before they go under ground, and also have a dc isolator as i am using a victron charge controller with no internal breaker.

[AGT]

The regs wanted dc isolators to start with
if I want to carry out maintenance during the day I would rather have an isolator separate from the inverter

[dlw]

The kit I bought is actually very good quality, EARU and they have been making AC and DC electrical equipment since 1999 and the MCCB's I have from them are exactly the same as the Tomzn one I have which are sold on Bimble and other UK shops.
The box has 25amp MCCBs, 25amp fuses and surge protectors.

[Stinsy]

The regs wanted dc isolators to start with
if I want to carry out maintenance during the day I would rather have an isolator separate from the inverter

Here you go:



They don’t update the rules for no reason. And they definitely don’t update the rules to remove a “safety” device without VERY good data showing that device causes significantly more problems than it solves. Casually ignoring important safety advice is setting up for failure. Which in this case involves burning your house down…

[AGT]

Yeah saw that , must be people buying crap off ebay and not terminating things properly, that’s leading to all these fires….I’m still having a DC Isolator.

[HML]

That video seems to be reporting a trade body recommendation, which doesn't count as a rule as far as I'm concerned. It also says that DC isolaters shouldn't be installed only IF there is an alternative in place, e.g. an integral isolater in the inverter, the implication being that DC isolaters should still be used if there is no alternative way to disconnecting the DC array from the inverter.

If the correct procedure is used to power down a system there is very little fire risk from a DC isolater. The AC should be removed from the inverter first, reducing current from the array to zero so there is no risk of a DC arc. Breaking the DC circuit under load is the cause of the fire risk arc, so don't break it under load.

[NoraBatty]

The kit I bought is actually very good quality, EARU and they have been making AC and DC electrical equipment since 1999 and the MCCB's I have from them are exactly the same as the Tomzn one I have which are sold on Bimble and other UK shops.
The box has 25amp MCCBs, 25amp fuses and surge protectors.

The difference being Bimble will have a supplier for their components that it can guarantee give you what you pay for.

You need that guarantee to make sure they are what they say they are.

If you go on holiday to turkey, you can buy a rolex for £20.
It doesnt mean its a rolex.

Can you guarantee your db that has a EARU label, is actually EARU, and not a cheap chinese knock off masquerading as such?!

[dlw]

Yeah saw that , must be people buying crap off ebay and not terminating things properly, that’s leading to all these fires….I’m still having a DC Isolator.

But the fires are all from professional installed systems, why would an isolator on an inverter do anything that an upstream one can't other than the type approval. Plugging a pair of wires into plug on an inverter that could have upto 1000vDC coming through them has got to be worse than plugging in then flicking a switch. I don't have a rotary islolator on my PV only the MCBs

I nearly had a fire on my panels which are at the back of my garden, one of the MC4 connectors musn't have had a very good connection and then had internal arcing and melted, there are so many components in a solar system that can go wrong.

The kit I bought is actually very good quality, EARU and they have been making AC and DC electrical equipment since 1999 and the MCCB's I have from them are exactly the same as the Tomzn one I have which are sold on Bimble and other UK shops.
The box has 25amp MCCBs, 25amp fuses and surge protectors.

The difference being Bimble will have a supplier for their components that it can guarantee give you what you pay for.

You need that guarantee to make sure they are what they say they are.

If you go on holiday to turkey, you can buy a rolex for £20.
It doesnt mean its a rolex.

Can you guarantee your db that has a EARU label, is actually EARU, and not a cheap chinese knock off masquerading as such?!

Yeah bought from their official store, everything is branded EARU except the enclosure, I get the Bimble guarantee, but then also understand that they buy from (overseas) suppliers and probably pay £6 for a breaker but by the time the consumer gets it it will be +£20 after markup and taxes

[NoraBatty]

Yeah bought from their official store, everything is branded EARU except the enclosure, I get the Bimble guarantee, but then also understand that they buy from (overseas) suppliers and probably pay £6 for a breaker but by the time the consumer gets it it will be +£20 after markup and taxes

Yes you pay for them acting as a middle man. You also pay for them only stocking things of a known quality that conforms to the regulations we have.
Ive not heard of EARU before.
Ive heard of Tomzn, but iirc they are also known as a bit of a budget brand.
You say they are the same. They look the same, that doesnt mean they are the same and perform the same.

Regardless of that, id rather pay a few pennies more and have a well known brand that conforms to all of the safety standards we have here to make the system as safe as possible. Mersen are my go to.
I understand what aliexpress is, i just take everything bought from it with a large pinch of salt.

I run a diesel heater in my boat.
There are many chinese versions of a webasto or eberspacher, and i have fitted a few for friends which work well, but they arent as good quality and have compromised in areas they should not have, which makes them unsafe to run unattended.
And i mean that literally, not as the often bandied about phrase to cover your back.
The stainless steel exhaust pipes they come with rust within a matter of weeks, the mufflers are tack welded in only 4 places and as a result leak carbon monoxide gas.
The diesel feed pipe is far too close to the exhaust and melts when run for extended periods, spilling diesel all over the red hot exhaust pipe. Even with lagging.

Every single one i have fitted i have insisted on the eberspacher ancilliaries to go with it because they last for years without failure, in comparison to the chinese cheap tat.

There is 316 stainless steel, and then there is chinese 316 stainless steel.

As has been said, breaking DC is no joke. I want to make sure what i have works when it is supposed to work, and is as safe as possible. Those breakers are the only thing standing between me and a house fire. Whilst many of us go for the cheaper diy battery options, we do tend to make sure there are quality safety components there to work as a failsafe when and if, things go tits up.