Confused by shower electrics

[regsmyth]

I visited a relative last year and noticed the electric shower was leaking. I bought a new one, but when I went to fit it realised there was a relay involved, to start/keep the extractor running once the shower was on/off.
There was a single black wire connected to one of the heating elements in the shower unit.
Perhaps the extractor started when the shower was turned on, then it continued to run for a few minutes after the shower was turned off. I can't quite remember.
Anyway, I couldn't access all the wiring in the loft above, but made a diagram of what I could see.
I didn't reconnect the black wire, or change any of the other wiring. I left it taped up securely in the airing cupboard.
The Isolator is in the airing cupboard, but the ceiling switch next to the shower controls the extractor.
The question is whether the system is safe to leave, or whether there's anything I should do to make it better/simpler.

Thanks for any advice,

 

[ericmark]

If the LABC signed it off, then clearly they think it is OK, if the LABC were not informed then clearly can't know if safe or not, it is like asking if I don't MOT my car will it still be safe.

 

[SUNRAY]

If thats just lightweight flex and single insulated flex (without a sheath) then at this distance I think its incorrectly mechanically protected.
I assume we're referring to a shower heater with a big fuse/MCB (32A or more) making the flex incorrectly electrically protected.

 

[regsmyth]

Well I could probably fit the exposed wires into some conduit.
The question is really about the black wire that used to be connected to the old shower element and whether it becomes live when the extractor is on. I don't know much about relays, and I can't be sure about where the wires I've put question marks on go, but hoped someone here might be able to see how it worked and help me understand what's the best thing to do.
Thanks,

 

[SUNRAY]

Well I could probably fit the exposed wires into some conduit.
The question is really about the black wire that used to be connected to the old shower element and whether it becomes live when the extractor is on. I don't know much about relays, and I can't be sure about where the wires I've put question marks on go, but hoped someone here might be able to see how it worked and help me understand what's the best thing to do.
Thanks,

If I'm honest, from the information you have provided so far I have 2 concerns:
1) The quality of the installation - if it's as you describe my recommendation is to either isolate all of the single wire and spresumably undersized flex or call in an electrician.
2) I'm not one of the people who willy nilly advise to get in an expert but in this case it appears you have stumble across a botch and I feel you are out of your depth.

 

[sparkwright]

Can you send photos?

Can't get your pdf file to work.

Are you certain the thin black wire isn't something do with a flow switch or Whale pump or something (to pump away the water in the shower tray)?

 

[EFLImpudence]

 

[regsmyth]

Thanks for the thoughts.
Yes I'm out of my depth but I hoped this would be fairly basic for some so I could get a clearer understanding of how this works and if that single black wire goes live at all when the extractor is on.
Here are some photos, but as I said the black wires disappear under the loft floor and I'm not sure how they might be connected.

 

[Sureitsoff?]

I quite like the idea of the shower turning on the extractor, but I don't like the bodged wiring.

 

[flameport]

Dangerous DIY lashup.
Fortunately the wires to the various items appear to be accessible so it could be replaced with something more suitable.

 

[Adam_151]

First of all note comments by @flameport

But I should imagine that where you have the four black wires and question marks, that the one at 11 o clock and the one at 5 clock are joined through / the same cable and the ones at 6 o clock and 1 o clock are as well

I can't see the relay conenctions properly.

But it looks like the 2 core flex has brown to the common of one set of contacts, while blue goes to A2 as the coil return, the single blue goes off to the pull cord presumably for a neon.
A1 is connected to the switched live after the controls obn the shower to energise the coil of the relay
The Normally open connection of the contact in use had a black single to the switched live of the fan
Another black single is connected in with the this and goes to the pullcord as an override for the fan, when tyhe switch is on this is energised from the single brown that runs upto the switch and has said, there is a blue neutral there which is likely for a neon to show its on override.
Another two core flex provides unswitched live and neutral to the fan

Its been done by someone who is familiar with relays, but not with electrical installation work.... perhaps auto electrician, or electronics hobbist as a DIY job

 

[sparkwright]

'Engineer' wiring. Quite neat, but not the way to do it.

 

[regsmyth]

Thanks all, comments appreciated and noted.
Thanks Adam for your analysis.
Below photo of ceiling switch.

So.. since I can't see the owner being keen on calling in an electrician and tiler to update the wiring, have I made anything worse or more potentially dangerous by leaving the black wire to the shower unit disconnected and taped up?

Thanks again.

 

[Adam_151]

You've just stopped the relay pulling in, which means that they'll have to turn fan on manually with switch (and then remember to turn it off to let the overrun time out), the rest of it is the same mess it was before, except it acheives even less now!

Personnaly I'd disconnect everything from the shower joint box, get a ELV fan kit (you appear to have a 2 core flex and a single buried in plaster to fan - no good for a timer fan that needs three conductors and is supposed to have an earth present), put the power supply (which has the timer in) in the loft, feed it from the lights via a 3 pole isolator, and use the 2 core flex that runs down to the fan to carry the 12v between psu and fan. Fit blankplate where separate pullcord is

 

[regsmyth]

Thanks for the reply Adam. Good plan.