Does a SPD need a dedicated MCB?

[westward10]

The original question can you pair it with the SPD no, mode 3 chargers need connecting to a dedicated circuit.

 

[oscar21]

The original question can you pair it with the SPD no, mode 3 chargers need connecting to a dedicated circuit.

Yes I know but I live in the real world. Regs like this were brought about so you didn't piggy back them off something like a socket circuit that was already loaded.

Lets take an immersion circuit, they used to run off a fused spur from the ring without any problem whatsoever, then someone said dedicated circuit only which made sense because all of a sudden socket circuits had more than a wooden lamp plugged into them.

Would I connect an immersion to the ring circuit nowadays? No way. Would I wire a boiler from the same circuit as the new immersion feed I've just wired, absolutely if it saved a second run of 2.5 across the house because the boiler uses such a minuscule amount of power that it wont affect the immersion circuit (that will never be used) one little bit.

The SPD uses zero current, it could probably be connected to the bus bar right on the other side of the MCB without any issue whatsoever, the electrons don't know where its connected so apart from upsetting someone who wrote a vastly overpriced book, in the grand scheme of things, it doesn't really matter.

And that philosophy has been proven the world over by countless millions of people.

 

[westward10]

Yes I know but I live in the real world. Regs like this were brought about so you didn't piggy back them off something like a socket circuit that was already loaded.

Lets take an immersion circuit, they used to run off a fused spur from the ring without any problem whatsoever, then someone said dedicated circuit only which made sense because all of a sudden socket circuits had more than a wooden lamp plugged into them.

Would I connect an immersion to the ring circuit nowadays? No way. Would I wire a boiler from the same circuit as the new immersion feed I've just wired, absolutely if it saved a second run of 2.5 across the house because the boiler uses such a minuscule amount of power that it wont affect the immersion circuit (that will never be used) one little bit.

The SPD uses zero current, it could probably be connected to the bus bar right on the other side of the MCB without any issue whatsoever, the electrons don't know where its connected so apart from upsetting someone who wrote a vastly overpriced book, in the grand scheme of things, it doesn't really matter.

And that philosophy has been proven the world over by countless millions of people.

None of that has any relevance whatsoever. As I said I don't care what you do but you came here and asked. Do what you like and bodge it that is clearly the way you operate because you are ignorant to improving your knowledge.

 

[Thomas knott]

Yes I know but I live in the real world. Regs like this were brought about so you didn't piggy back them off something like a socket circuit that was already loaded.

Lets take an immersion circuit, they used to run off a fused spur from the ring without any problem whatsoever, then someone said dedicated circuit only which made sense because all of a sudden socket circuits had more than a wooden lamp plugged into them.

Would I connect an immersion to the ring circuit nowadays? No way. Would I wire a boiler from the same circuit as the new immersion feed I've just wired, absolutely if it saved a second run of 2.5 across the house because the boiler uses such a minuscule amount of power that it wont affect the immersion circuit (that will never be used) one little bit.

The SPD uses zero current, it could probably be connected to the bus bar right on the other side of the MCB without any issue whatsoever, the electrons don't know where its connected so apart from upsetting someone who wrote a vastly overpriced book, in the grand scheme of things, it doesn't really matter.

And that philosophy has been proven the world over by countless millions of people.

Until the immersion element blows down to earth and you've suddenly got immersion and no boiler either.

Also the immersion would be on a high current MCB the inrush current and high fault current of a earth fault would likely blow the PCBs of the boiler.

Of course it'll work fine but there's a reason we separate loads and design circuits based on the load they carry and separate vulnerable equipment.

Put the SPD on its own breaker as the manufacturer requires in their data sheet. And a 3 phase charger will require more than just a MCB to protect it. The last fast charger I helped to put in had to have a 4 pole breaker that disconnected the earth and an earth cage under the concrete.

But you'll just stick it in with the SPD to save on a new enclosure just below the DB.

 

[oscar21]

Until the immersion element blows down to earth and you've suddenly got immersion and no boiler either.

Also the immersion would be on a high current MCB the inrush current and high fault current of a earth fault would likely blow the PCBs of the boiler.

Of course it'll work fine but there's a reason we separate loads and design circuits based on the load they carry and separate vulnerable equipment.

Put the SPD on its own breaker as the manufacturer requires in their data sheet. And a 3 phase charger will require more than just a MCB to protect it. The last fast charger I helped to put in had to have a 4 pole breaker that disconnected the earth and an earth cage under the concrete.

But you'll just stick it in with the SPD to save on a new enclosure just below the DB.

Most of thats rubbish, you must know that. If the immersion blew you would simply switch it off at the DP switch and carry on using the boiler circuit, apart from the fact the immersion is only used if the boiler breaks, not the other way round. As for blowing the PCB fuses, how? you could spur off a socket for a boiler FCU and plug a big heater into the socket, if the heater wen't bang that wouldn't affect the boiler would it.

Secondly how will putting a separate enclosure next to the mains help my situation, its either a complete new board or an additional 3 phase board, splitting the tails and all the work that ensues, it will cost a good few hundred either way and the bloke doesn't want to pay that. As it happens the manufacturer have got back to me and stated it needs RCD protection so I will be fitting a separate enclose for that. They didn't mention earth grids etc. Why would they, what happens if someone doesn't park on it and charges their car?

Normally I'd say I cant do it but he is the best giver of work and payer we've ever had and I'm not putting that at risk by being awkward, especially when the next electrician turns up, bodges it in 5 minutes and says how easy it was. So if the worst that will happen is a few regs fans have a little cry then I'm all for it.

 

[westward10]

What is your earthing system?
What type of RCD will you use?
Don't forget DNO notification.

 

[oscar21]

TNC-S
Type B
Bloke says he doesn't care.

 

[westward10]

If this is for outside charger and it doesn't incorporate open PEN protection you need to put measures in place. Most do now but something from EBay I would be dubious about.
But hey you don't care.
DNO notification is required.

 

[oscar21]

If this is for outside charger and it doesn't incorporate open PEN protection you need to put measures in place. Most do now but something from EBay I would be dubious about.
But hey you don't care.
DNO notification is required.

I do care, I don't do dangerous stuff, I just don't do everything anyone tells me to do, if I think a reg is daft or over the top I'll do what I think is right, I use common sense instead of blind faith. The limited instructions I linked to earlier state that it has open PEN protection and ground protection (whatever that is) you have to go into the display settings to turn it on apparently.

 

[oscar21]

What I do find baffling though is this is meant to be the future, the government want everyone in little electric euro boxes but if I was doing a similar job to this for an independent customer I'd want about £2-3K to even think about getting involved, its not a line of work I would like to get into at all, far too many hoops to jump though.

There must be a fair few others that think like me as well which can only cause problems for the end user, they will want an easy life and just end up buying another diesel. .