Electric Shower Installation A Washout

[ianhni]

Hello all

I've another one of those with shower woes...

After completing the installation of an 8.5kW Mira Vie shower (new 10mm cable clipped at approx.6.5m length, connected to an isolator switch and 40A mcb with 63A RCD) I'm pleased with the results save for a very crucial outcome. The mcb keeps tripping once energised and I press the shower starter switch. 

As part of the troubleshooting process, I've checked the shower (including completely replacing the shower unit) so I'm sure it's not the shower heater element etc; I checked the clipped 6.5m length of 10mm cable then went ahead and completely replaced the 10mm cable, mcb and RcD and spent time ensuring the cable isn't compromised in any way. The only way I get the shower to operate properly is when I do a straight run (non clipped) 10mm cable for 5m directly from the consumer unit to the isolator switch and shower. Is this something anyone can offer any guidance on. For example, is it possible that the problem relates to the slightly longer 10mm cable, or the fact that it is straight and not tracked underfloor. I consider myself to be a highly comptent general DIYer (the benefit of starting out with modest income and a load of desire to learn new skills) but I'm hoping this forum will enlighten me.

I should've simply installed another thermostatic shower!

Thanks in advance...

Ian

 

[Andy™]

faulty wiring at the isolator? only thing you didnt say you had changed

of course, getting a sparky in to fault find would have probably been much easier and fault found within minutes, rather than completely replace cable etc

 

[steptoe]

are you sure you havent mixed up the earth and Neutral connections at the shower?

some showers have very badly marked terminals, ie, the marks dont actually line up with the correct terminals.

oh, just re-read, its the MCB,

sounds like you have a crossed live, most likely wired the isolator wrongly, [as Andy implies , sort of]

TBH, this sounds weird, very,

where abouts in the wee spot are you?

 

[SPECIAL LOCATION]

Hello all

I've another one of those with shower woes...

After completing the installation of an 8.5kW Mira Vie shower (new 10mm cable clipped at approx.6.5m length, connected to an isolator switch and 40A mcb with 63A RCD) I'm pleased with the results save for a very crucial outcome. The mcb keeps tripping once energised and I press the shower starter switch. 

I consider myself to be a highly comptent general DIYer (the benefit of starting out with modest income and a load of desire to learn new skills) but I'm hoping this forum will enlighten me.

I should've simply installed another thermostatic shower!

Thanks in advance...

Ian

As I said on another thread recently...

http://talk.electricianforum.co.uk/topic/23507-advise-needed/

IMHO installing an electric shower is not a DIY job...

Your post confirms this to be true...

The correct sequence of DEAD TESTS prior to enrgising the unit would have prevented this fault...

that is why competent electricians use the correct test equipment...

We don't just by the test gear as a hobby interest...

it is to ensure the safety of all electrical alterations done!

You have probably wasted  more time and money swapping unnecessary items...

than had you followed good wiring practice as per the guidance in BS7671 would have prevented your fault.

p.s.

RCD's are rated in miliamps not amps...

you do not have a 63A RCD..

As is always the case the person who considers themselves to be  "Highly competent"..

is a gnats whisker away from being an electrical novice working outside of there abilities..

Get someone with the correct test equipment to come and test the cable for you....

then start from whatever conclusions these tests come to...

You should not simply joins some wires then switch on to see if something works!

Very dodgy practice!!!

p.p.s..

You may have contravened building regs as well dependant upon which part of the country you are in.

:coat

 

[batty]

Glad Part p is working and if he is in Scotland maybe they should have part p.

 

[ProDave]

Glad Part p is working and if he is in Scotland maybe they should have part p.

Noooooooooooooo :coat

 

[steptoe]

methinks, he may be, in norn iron, 

BTW, part P doesnt stop anything wrong, bad, or illegal being done,

it just costs scam members time and money.

 

[ProDave]

I think the OP needs to clarify just WHAT trips when he turns the shower on.

I can think of many faults that would make the RCD trip when you turn it on, but I can't think of why the MCB would trip when you turn the shower on (other than a faulty shower) but since it works with the other bit of cable the shower must be okay.

 

[NozSpark]

LIke the others there are a few reasons why it might have tripped... Mainly it being wired incorrectly.

Can I just clarify how you determined that the cable is 10mm??????

 

[Evans Electric]

Avoiding the fact that you should have had a sparky in ...

Q1  Is it the MCB  or the RCD thats tripping  .?

Q2  What is the rating of the RCD  in mA   ?  ( Could it possibly be a 10mA ?)

Q3  Are you conected to a split-load board and if it IS the RCD , is your N in the wrong bar? 

Q4  As Steppers says , have you crossed any wires in the isolator ?

Was about to say the MCB could be fauty  but you've had it working .

And you probably didn't need 10mm for the 8.5KW  .

 

[sprocketflup]

weirdly enough, I have to go and investigate exactly the same problem at some point next week, the customer told me on the phone that it was a 10.5kw shower on a 30A plugin breaker. Hmm, I wonder what it could be?..............

 

[SPECIAL LOCATION]

Is it a split load board with the neutral going to the wrong half of the board???

opcorn

methinks, he may be, in norn iron, 

BTW, part P doesnt stop anything wrong, bad, or illegal being done,

it just costs scam members time and money.

Are you deducing something from the OPs name.. not just reading the content of the post???

:B-

 

[steptoe]

Is it a split load board with the neutral going to the wrong half of the board???

opcorn

Are you deducing something from the OPs name.. not just reading the content of the post???

:B-

a bit of both, the wording simply made it a bit more to me,

his name is Ian, very much a NI name, its the NI version of John, he has ni at the end of his name,

and the way he has worded his post is very much a 'proper' go at 'proper' english for a norn iron person, much as I try to do.

 

[Evans Electric]

Hmmmm !   Elementary my dear Watson .    And he types in NI way ...I suspect he is Protestant and drives an auld vern !! :innocent

 

[batty]

And as the shower doesn't work he has a washout in the rain.

 

[steptoe]

shud hay putt in a poor sure

 

[sparkytim]

A common DIY mistake is to get the pull switch connections wrong and put a dead short on when switching on.

 

[Evans Electric]

shud hay putt in a poor sure

Thought I'd responded to this ???

Yes Stepps ...a power shower.

 

[Steve3948]

Never liked Electric Showers, especially in hard water areas, total rubbish.

 

[Andy™]

Moving on....

...i dont think he's coming back....