New CU Fitted a few teething Issues to sort.

[KRIS537]

Had a new CU fitted at the weekend. But there where a few teething issues to sort out.

First one was the garage kept tripping the electrics out, so the electrican put it on a none RCD protected curcuit. This not an issue for me atm as im having that redone at some point as a workshop.

The main one was the Immersion hot water cylinder. First off the feed to this also powers the boiler but is only a 1.5mm cable. He says thats fine for a boiler but not an Immersion. so im going to have a 2.5mm cable fitted soon as a seperate feed. The issue I have is the MCB trips every so often, but the RCD doesnt. What could be causing this issue?

 

[KRIS537]

Seriously though, you are doing the right thing but why not get all the problems sorted at the same time as the DB change?

As said earlier in the thread down to money, espically this close to christmas. I know it will prob save me money in the long run, but im also trying to coinside with decorating etc, and routing some of the ccbales so all he has to do is wire it up.

 

[Plonker 3]

Fair enough. But why has he the garage been left on only a MCB? If as you say the wiring is in a mess? Surely this makes a mockery of having the mew DB installed

 

[KRIS537]

just an updated have fitted a new imm element and the MCB is still tripping. The MCB is a 6amp. I would of said 6amp isnt correct should be 16amp/20amp type B?

 

[DPG]

What is the rating of the immersion element (watts)? This should help you answer that. Daz

 

[Geordie Spark]

just an updated have fitted a new imm element and the MCB is still tripping. The MCB is a 6amp. I would of said 6amp isnt correct should be 16amp/20amp type B?

Yes ..... the 6 amp MCB is very probably too small, but don't just go stuffing a bigger one in without first knowing how much current you immersion heater is drawing.

If you know its rating (how many watts it is) you can work out how many amps it draws from the formula: I = P/u which in layman's terms is Amps = Watts/Volts

SO *if* your immersion heater is 3kW it is 3,000/230 = 13.04 Amps. In this case, you need to be looking to fit a 16amp MCB but it's all depending on how many watts your immersion is rated at so you need to check that first.

Always use the figure 230 for your volts BTW.

 

[telectrix]

and make sure it's fed in 2.5mm, not bell wire.

 

[KRIS537]

couldnt find the watts anywhere not even on screwfix website. the side of the box is 2.7kw for 230v or 3kw for 240v. The boiler is on same circuit so should i fit the 20amp? or should i run the boiler off the 6amp, and imm of a 16amp. will be calling the sparky back as he fitted the 6amp.

 

[GLENNSPARK]

couldnt find the watts anywhere not even on screwfix website. the side of the box is 2.7kw for 230v or 3kw for 240v. The boiler is on same circuit so should i fit the 20amp? or should i run the boiler off the 6amp, and imm of a 16amp. will be calling the sparky back as he fitted the 6amp.

christ i give up!!!

 

[SYKRAPS]

couldnt find the watts anywhere not even on screwfix website. the side of the box is 2.7kw for 230v or 3kw for 240v. The boiler is on same circuit so should i fit the 20amp? or should i run the boiler off the 6amp, and imm of a 16amp. will be calling the sparky back as he fitted the 6amp.

These are the wattages in red

 

[Geordie Spark]

couldnt find the watts anywhere not even on screwfix website. the side of the box is 2.7kw for 230v or 3kw for 240v. The boiler is on same circuit so should i fit the 20amp? or should i run the boiler off the 6amp, and imm of a 16amp. will be calling the sparky back as he fitted the 6amp.

OK ..... it's a 16 amp MCB you need for this immersion heater and - as Tel says - 2.5mm T&E cable.

The 2.5 T&E goes from the 16 amp MCB in the consumer unit to a 20 amp switched flex outlet something like this: 20 Amp DP Switch with Flex Outlet and Neon next to the immersion heater & from there a bit of 2.5 3 core heat resisting flex to the immersion heater itself.

I'm not normally this helpful, but it's Christmas.

 

[KRIS537]

OK ..... it's a 16 amp MCB you need for this immersion heater and - as Tel says - 2.5mm T&E cable.

The 2.5 T&E goes from the 16 amp MCB in the consumer unit to a 20 amp switched flex outlet something like this: 20 Amp DP Switch with Flex Outlet and Neon next to the immersion heater & from there a bit of 2.5 3 core heat resisting flex to the immersion heater itself.

I'm not normally this helpful, but it's Christmas.

I thanks, will get teh sparky to fit a 16amp on his next visit. Everything else is as you state 2.5mm T&E and 20amp DP neon switch with 2.5, 3core heat flex.

 

[Octopus]

couldnt find the watts anywhere not even on screwfix website. the side of the box is 2.7kw for 230v or 3kw for 240v. The boiler is on same circuit so should i fit the 20amp? or should i run the boiler off the 6amp, and imm of a 16amp. will be calling the sparky back as he fitted the 6amp.

Mate, I don't believe he exists.

 

[DPG]

He either doesnt exist, or doesnt have a clue what he's doing. Daz

 

[Octopus]

He either doesnt exist, or doesnt have a clue what he's doing. Daz

My money is on "doesn't exist"

 

[KRIS537]

My money is on "doesn't exist"

God I wish I was a perfect as you!

 

[DPG]

I don't think it's about being perfect. A couple of questions to begin with:

Why are you asking on here what size MCB to buy for your electrician?
Why has your electrician fitted a 6A MCB for an immersion heater?
Why are you buying parts at all when you don't even know what a kW is?

Daz

 

[KRIS537]

I don't think it's about being perfect. A couple of questions to begin with:

Why are you asking on here what size MCB to buy for your electrician?
Why has your electrician fitted a 6A MCB for an immersion heater?
Why are you buying parts at all when you don't even know what a kW is?

Daz

Oh let me see on this erm I can get electrical parts at cost, or even free for that instance. 2nd I dont know why he fitted a 6amp. and i know exactly what a kW is where have i ever posted that!

 

[DJ Ovengloves]

Post 47 and then someone even highlighted them in red!

Oh let me see on this erm I can get electrical parts at cost, or even free for that instance. 2nd I dont know why he fitted a 6amp. and i know exactly what a kW is where have i ever posted that!

 

[KRIS537]

couldnt find the watts anywhere not even on screwfix website.

All i was saying there is there not listed on the screfix website so i fail to see your point./

 

[DPG]

Quote from yourself earlier: "couldnt find the watts anywhere not even on screwfix website. the side of the box is 2.7kw for 230v or 3kw for 240v"

Need I say more?

Daz

 

[KRIS537]

stll fail to see your point. think im missing the but in that sentance

 

[DPG]

You're missing something. Properley rated MCBs for a start. A qualified electrician aswell possibly? Daz

 

[Octopus]

God I wish I was a perfect as you!

Didn't say I was perfect so don't be a knxb

I'm suggesing that you aren't being honest, and I'm yet to be convinced you are.

 

[mydigitalhome]

On the continent it is normal to see immersions fed from plug top and lets face it we have the best plug top in the world so can understand the comments on this tread. But saying that it would not be the way I would wire it.

 

[brman]

On the continent it is normal to see immersions fed from plug top and lets face it we have the best plug top in the world so can understand the comments on this tread. But saying that it would not be the way I would wire it.

until about 12 months ago my own immersion heater was wired via a plug/socket. Worked fine but then it wasn't fused by a 6A MCB... :lol:

 

[SirKit Breaker]

well, having seen plugs welded into sockets on just 2kW kettles, either their calculations are wrong, or sockets compliant with BS1362 just ain't.

Not to mention the fact that DIY Charlies will save a few pence by buying un switched sockets and repeatedly drag the plug out when it is under load and this definitely wont do the plug any good. Again it may be acceptable under the "Regs" but how many times do i say that common sense takes precedence over the regs.

Cheers...........Howard

 

[Octopus]

Not to mention the fact that DIY Charlies will save a few pence by buying un switched sockets and repeatedly drag the plug out when it is under load and this definitely wont do the plug any good. Again it may be acceptable under the "Regs" but how many times do i say that common sense takes precedence over the regs.

Cheers...........Howard

This one isn't DIY Charlie, its DIY KRISH537

 

[Marvo]

Thanks to everyone who gave good info, there's a lot of sound advice been given.

I'm closing the thread at the request of the OP.