Trouble shooting on a shower installation

[Chopz Choppa]

Firstly i installed a 7.5kw shower, wired with a 10mm t/e, protected with a 40a mcb, on the rcd side of the board and with a 40a double pole switch. Now when i come to turn on the switch everything is fine, the neon light comes on hurray, but when i turn on the shower it trips the rcd. I did a continuity check on the cable running from the switch to the shower and cable seems fine, i also got up in the loft an visually inspected the cable an its fine. so i had the manufacturer look on the shower who claimed it was fine and i also turned off everything on the rcd side of the board leaving just the shower powered up,just to check its not overloading when the shower comes on and no joy still tripping the rcd, PULLING MY HAIR OUT CAN ANYONE PLEASE SHED SOME LIGHT ON THIS MATTER CHEERS!

 

[malcolmsanford]

Did you put the neutral in the correct neutral bar?

 

[Chopz Choppa]

you know what i will check i believe so but u might be right if so then im gonna feel like a right donkey and will buy myself a rope and some ladders lol cheers for that never thought about that one.

 

[Deleted member 9648]

Firstly i installed a 7.5kw shower, wired with a 10mm t/e, protected with a 40a mcb, on the rcd side of the board and with a 40a double pole switch. Now when i come to turn on the switch everything is fine, the neon light comes on hurray, but when i turn on the shower it trips the rcd. I did a continuity check on the cable running from the switch to the shower and cable seems fine, i also got up in the loft an visually inspected the cable an its fine. so i had the manufacturer look on the shower who claimed it was fine and i also turned off everything on the rcd side of the board leaving just the shower powered up,just to check its not overloading when the shower comes on and no joy still tripping the rcd, PULLING MY HAIR OUT CAN ANYONE PLEASE SHED SOME LIGHT ON THIS MATTER CHEERS!

Malcolm has the most likely cause.....but why are you doing a continuity test to trace an RCD tripping issue?.....RCD's trip because of a current imbalance,if the neutral is definately in the right bar you should be looking for a low IR to earth...which means an IR test.
Before energising and before discovering the RCD trips when the shower runs you should carry out the following tests in this order
Continuity...(R1+R2)
Insulation resistance
then energise and test-
Zs
RCD trip times and functional.

If you do these tests on your new final circuit and get satisfactory results,and correctly connect at the CU....the RCD wont trip.

 

[Chopz Choppa]

you are right these tests should be done firstly b4 energising but i have not got these testers yet but will definatly be picking one up asap as this like you say would not of happenened in the first place , cheers.

 

[Deleted member 9648]

you are right these tests should be done firstly b4 energising but i have not got these testers yet but will definatly be picking one up asap as this like you say would not of happenened in the first place , cheers.

Good luck with it...but get your tin hat ready mate...:59:............:angel_smile:

 

[ezzzekiel]

so youre installing a shower in a special location and not carrying out any testing which means no certification which means no partp.

How would you expect to troubleshoot or ensure an installation is safe with no test gear.

 

[kung]

you are right these tests should be done firstly b4 energising but i have not got these testers yet but will definatly be picking one up asap as this like you say would not of happenened in the first place , cheers.

Part p ? what continuity tester were you using ? was it a multi meter and if so given the cable length what reading in ohms were you expecting on the tests and what reading did you get ? or was it a beep function ? im not trying to say you dont know what your doing by any strech buy unless you know 100% and have the correct test equipment and competent as in part p etc electricity can be dangerous esp when mixed with water ! please dont take this the wrong way i dont know your situation on quals exp etc but as no full dead tests were done before energization makes me believe otherwise. Be safe ! its all about safety. Hope you get it sorted and good luck.

 

[Octopus]

you are right these tests should be done firstly b4 energising but i have not got these testers yet but will definatly be picking one up asap as this like you say would not of happenened in the first place , cheers.

How can you be doing safe competent electrical installations without testers. Also you're obviously not registered either so you need to consider what you can and can't do before you hurt somebody (or more likely yourself)

 

[Chopz Choppa]

i will check the neutral and have an inspector out to test and verify as u are all right.

 

[trev]

When you say you will get an inspector out, what do you mean by that? No competent electrician I know will sign off anyone else's work unless they have been heavily involved right from square one. If you mean LABC, they expect the person installing to test and certify, some will send a council spark out to carry out the verification but that usually costs a considerable amount on top of the LABC fee.

 

[ezzzekiel]

no one is having a go just friendly advise.

partp is one matter which in my humble opinion if your competent and qualified then youre competent and qualified regardless of partp.

however no test equipment doesnt meet the above criteria so that is a must.