hi, i am installaing a hot tub, i have installed a 32a mcb at the db and run a 3 core swa in to a junction box which contains a 40a rcd, the tub is second hand therefore has a swa coming from the tub already connected, after powering the circuit it tripped the main rcd in the db and will not stay energized, im aware that the 40a rcd is higher than that of the primary mcb rating and that it is poor discrimination but did not think this was that major of a problem that it would not even allow circuit to be turned on, any ideas?
hot tub installation
- Thread starter thomo87
- Start date
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It's the 30mA on the RCD which is important, not the 40A.
I suggest you get an electrician to test properly before you switch on again.
It seems like you are just guessing.
I suggest you get an electrician to test properly before you switch on again.
It seems like you are just guessing.
it is a 30ma rcd but 40a which is higher than that of the mcb in db which is poor discrimination but its all i had in my van so installed it just to check the tub worked then change it, the person who had it befor had the junction box adj to db with the 40a rcd and an additional mcb being fed via rcd and its the same junction box and rcd i used, all i have done is take a 4mm 3 core from db into junction box in shed and connected straight into rcd and connected tub cable into the load side, the tub connections have not been altered but it still trips, its a 7.5kw tub so requires a 32a mcb. i am an electrician but think i may of underestimated it thinking it would be the same as any other equipment.
The information you have posted already highlights several mistakes you have made.
Electrician or not, for the safety of you and whoever else will be using this tub, please find someone who knows what they are doing to install it properly.
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what mistakes would they be?
A 3 core SWA
2 RCDs in series
You do not appear to understand what the 40A rating on the RCD actually means
how would you recommend its done then?
What he said.
I don't think you're going to get anywhere with this one - you've come, as an electrician, to a DIY forum, asking how to do a job that you're (presumably) charging a customer for. I just hope for your sake that nobody gets killed as a result of your unwillingness to admit that you've bitten off more than you can chew on this job.
No it isn't, but you repeatedly saying that it is shows that you have no idea of the difference between an MCB and an RCD.
No you f*****g aren't.
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It's at times like these I realise that there is something wrong with the 'system'.
I wonder whether thomo87 is a member of a notification scheme and if so which one.
I see BAS has replied before I managed to post and on this occasion I fully agree with him (her?).
Question to thomo87 - what do you think an RCD does? Please answer in some detail.
I wonder whether thomo87 is a member of a notification scheme and if so which one.
I see BAS has replied before I managed to post and on this occasion I fully agree with him (her?).
Question to thomo87 - what do you think an RCD does? Please answer in some detail.
No mention of an isolator.
Bet your neutrals are muddled at the consumer unit.
What size SWA?
Why an RCD outside in a 'junction box'?
I suggest you google what an RCD, MCB and RCBO is.
Bet your neutrals are muddled at the consumer unit.
What size SWA?
Why an RCD outside in a 'junction box'?
I suggest you google what an RCD, MCB and RCBO is.
So the job was not planned ?
If you knew what you doing, ( ie you had the necessary knowledge ) then you would not have made a wiring error that tripped the breaker or if you did you would be able to fault find and rectify your error.
That suggests that the trip is happening because of a fault in second hand equipment. While test equipment ( you do have test equipment don't you ) will not tell you if the pumps rotate and the lights and bells work it would tell you that there was a problem or fault that would lead to tripping of protective safety devices.
Or maybe you simply have no idea of what is involved in installing a hot tub in a way that leaves it safe to use.
Suppose it had "worked" and no tripping occured. Would you have then replaced that "all I had in my van" device and left it as a "safe" installation ?.
The mention of a van with "things electrical" in it suggests you operate as an "electrician". If you do and based on the content of this thread I hope your public liability insurance is in effect.
I wonder if he's a hot-tub installer who scraped through a 5-day course and a defined-scope assessment and thinks that makes him an electrician?
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