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?

 

[telectrix]

firstly, what is the rating of the breaker that is tripping? he is correct in saying that 1.5mm is OK for the boiler,. it would just about cope with the immersion heater as long as it was not de-rated due to insulation, but the imm. should have it's own dedicated 2.5mm on a 16A MCB. it's also possible that the imm. element is breaking down.

 

[Steve_P]

What ^^^^Tel^^^^ says.

What does the electrician you had in to do the CU change say?

 

[KRIS537]

thanks for the reply, I think it is a 16A MCB but not sure will check when i get home. Will add a new element into the mix of things lol. Im supplying the parts to the electrican to fit and routing the cable to where it needs to go, as this will save me money and hes happy for me to do this.

The current electrics are 1.5mm to a junction box, that goes to boiler and motor, and off to a switched fuse, then off to another switch unit to turn the heater on etc. I was hoping to fit a switch then a normal plug socket that the imm plugs into to. is this acceptable?

 

[telectrix]

immersion heater needs 2.5mm radial to either a D/P switch or a D/P FSU. not a plug and socket.

 

[KRIS537]

yeah i was planning to get him to fit this LAP 20A DP Water Heater Switch with Neon White | Screwfix.com then to a 3pin plug socket.

 

[telectrix]

no..... from D/P switch direct hard wired to 2.5mm H/R flex to heater.

 

[KRIS537]

cheers Tel.

 

[telectrix]

why anyone would want to supply a 13A heavy load through a plug and socket with all the issues of poor connections, baffles me.

 

[Rockingit]

why anyone would want to supply a 13A heavy load through a plug and socket with all the issues of poor connections, baffles me.

I had an interesting conversation with my (ex) NICEIC engineer about this a couple of years ago. A BS socket is test rated at 19A, and the ESC(?) released a study a while back after concerns for using normal plug and socket for charging electric cars that concluded they could find no evidence that a BS1363plug and socket was not suitable for a continued heavy draw.

So the engineer scratches his head, can't give me an answer as to why you can't connect an immersion this way (not that I do, btw) and goes off to call somebody else deeply hidden and senior within the NICEIC. And the conclusion was that they couldn't come up with an explanation either and thought that 554.3.3 was probably left in for historic reasons and may get removed in the future.

 

[telectrix]

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

 

[KRIS537]

why anyone would want to supply a 13A heavy load through a plug and socket with all the issues of poor connections, baffles me.

I have not had enough caffine yet lol. Reson i Said that is becasue the current setup has a switched/fused socket. Similar to this LAP 13A Switched Fused Connection Unit White | Screwfix.com

Trust me this house is an electrical nightmare, what scares me the most the previous owner was an electrican. Dont worry hes not done any work to my house since i bought it lol. He has normal grey PVC cabling powering outside sockets, the garage etc etc. Im slowly getting stuff corrected and done right.

 

[Octopus]

Time to find a new sparky??

Out of interest did he give you an EIC for the board he fitted??

 

[KRIS537]

hi he only fitted it on Sunday is this something they should of wrote out on the day or something they have to send off for?

 

[Rockingit]

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

I'm not in disagreement with you, though my first thought on things like kettles welded is 'how well were they wired in the first place?'