Fitting A Shower

[Dairyspark]

I need some help lol I was helpin to fit a shower in my mates house and I ran a 10mm cable from a 40A b type breaker to a double pole shower switch then to the shower made it all look nice did an IR test and all checked out fine (please advise more testing if required) put on the power and the shower light came on, turned on the shower and the rcd tripped, unhooked the shower tested for continuity between all points and that was fine, could it be a faulty shower or am I missing somethig completely? And before you shout at me yes I am an apprentice, if I have done it completely wrong I will get my boss to help just thought I'd ask on here first

Cheers

Bobby

 

[Revved Up Sparky]

Did you do an IR test between the DP switch and the shower ?.

 

[Marvo]

Did you connect the neutral of the shower circuit to the correct neutral bar in the CU? If you IR tested the circuit and the shower then most likely connected wrong. The power indicator lamp alone is probably insufficient current to trip the RCD so it only tripped once the heating elements kicked in.

Maybe lure your boss around with the mention of a couple of cold beers and casually ask him nicely to check your connections.

 

[Steve3948]

I need some help lol I was helpin to fit a shower in my mates house and I ran a 10mm cable from a 40A b type breaker to a double pole shower switch then to the shower made it all look nice did an IR test and all checked out fine (please advise more testing if required) put on the power and the shower light came on, turned on the shower and the rcd tripped, unhooked the shower tested for continuity between all points and that was fine, could it be a faulty shower or am I missing somethig completely? And before you shout at me yes I am an apprentice, if I have done it completely wrong I will get my boss to help just thought I'd ask on here first

Cheers

Bobby

Are you saying light was on the pull switch or shower, before you pulled the switch ??

 

[m4tty]

Most probably neutral in wrong bar mate. Check this first

 

[m4tty]

And really you should have done continuity test on cable, ins res, polarity, efli (zs) and rcd test before livening up but not end of world I know many 'wire and fire' sparks lol

 

[SLIPSHOD & SLAPDASH]

As above , check the neutral connection is with the correct bar for the rcd. If that fails It's not that uncommon for new equipment to have an internal fault so try a lightbulb in place of the shower and see if the rcd still trips.

 

[boltonsparky]

Did you IR test with the shower connected? If so and you IR tested across L + N at 500v you may have damaged the internal circuitry of the shower if it's an all singing and dancing model which may be tripping the RCD (just thinking of possible alternatives to those mentioned above).

If you just IR tested just the cable and this was fine then at 250v IR test the shower from L to E and then N to E, should show up any faults internally with the shower without causing any damage.

Did you IR test before putting covers back on the switch? If so have you clipped a cable putting the switch plate or cover back causing a short to earth?

 

[Dairyspark]

I tested it with the cable disconnected from the DB to the switch and then from the switch to the shower both discounted polarity is fine and I don't have a earth fault tester so that's the only test I couldn't do and I'll test the ir at the shower at 250v I didn't want to test it because I thought I would mess up the shower and continuity was done with all covers on and it checked out fine, neutral is in the correct bar and yes I turn on the breaker and the light on the switch comes in when switched, then the light on the shower comes on and when you turn on the shower it trips the rcd I shall test the ir on the shower and see how that goes thanks for the replies so far and not for shouting at me lol

 

[Doc Hudson]

You say the cable was disconnected? You need the earth connected to the electrical earth & any bonding as it could be a cable damaged touching an earthy pipe. But if your tests have all three cores of the cable open circuit, during the tests it would not show the earth path until you connect your CPC back to the earth bar.

Doc H.

 

[Dairyspark]

Ah right ok ill test again with earth connected thank you

 

[SPECIAL LOCATION]

Ah right ok ill test again with earth connected thank you

Hmmm...

sounds like a possibility for one cause then... :C

If you have a line or neutral conductor, nicked or nailed or trapped or screwed making contact with "Building Earth".....

But..

You have only tested between L, N, E conductors on a cable that is completely open circuit to building earth..

Then there is the Chance of a L or N fault to building earth that you have not tested too..

The Doctor had a thread about this not so long back while on the old place as he discussed some content of his "Part-P Doctor" book...

IIRC there had been some case of bods IR testing a ring final with all conductors open circuit from the CU..

but a cable had been damaged going through one of those metal framed construction stud walls...

I think the whole wall went live or somthing....?

If I could figure out the new search feature.. I would have stuck a link on..

But I cant.. (or cant be bothered, cuz I am just finishing me mug of tea then I am off out!!)

:coffee

There is no harm testing between L-N-E to verify no damage between conductors...

but you do need to also check the live conductors to electrical/building earth.

easiest way is by joining CPC to the earth bar at CU then test L & N to the earth bar...

Don't forget this also assumes you have proved earth continuity along the whole length of the circuit!

No good testing L&N to earth if CPC is broken part way down the circuit..

(e.g. open circuit in the back of a switch!)

IF those cable tests all pass ok, and the conductors are connected on the correct bars in the CU, then its either dodgy shower or something dodgy in the switch...

Is the switch a crabtree cord pull or one of those naff square things??

http://www.screwfix....d-sw-neon/90597

If its a square one...

that would be second on my list of causes after proving the cable fully.

 

[Dairyspark]

Hello again went back round tonight and tried again and found the problem (prepares to be laughed at) neutral was in the wrong bar silly silly me anyway thanks for all the advice guys much appreciated

Cheers

Bobby

 

[Doc Hudson]

Hello again went back round tonight and tried again and found the problem (prepares to be laughed at) neutral was in the wrong bar silly silly me anyway thanks for all the advice guys much appreciated

Cheers

Bobby

Thank you for the feed back. I always think it helps others reading when they can also read the conclusion to a problem, not just a question and a list of advice.

Doc H.

 

[Marvo]

It's always good to hear what the problem was. I wouldn't feel too bad, if you don't make mistakes you don't get experience.

 

[ParkySparky]

You won't be the first nor the last!! Least you worked through possible solutions and sorted the problem! The joy of gaining this experience is that you'll know for next time!!

 

[Sharpend]

Sparkybob,

Respect for your honesty, you'll go along way.

Others may have embellished the fault to save face.

 

[SLIPSHOD & SLAPDASH]

and found the problem (prepares to be laughed at) neutral was in the wrong bar

Cheers

Bobby

ROTFWL ROTFWL ROTFWL ROTFWL ROTFWL ROTFWL ROTFWL ROTFWL ROTFWL

But thanks for letting us know.