Bathroom Fan and BARE TAILS problem

[Clitheroe]

Evening Everybody

Just went to somebodys house this evening to look at a bathroom fan making a slight "humping" sound and not turning so freely.

Firstly what is probably the problem with the fan, could it be dust/fluff/dirt? I have not taken a proper look yet.

I did remove the very front cover though and it has a two core flex permanently live an neutral and a single core 1 or 1.5mm live core as switched live (I tested them). However it only comes on when the shower isolater is operated and when I isolated the shower circuit it does not work at all.

1)This sounds like it is supplied from the shower circuit, would everybody agree?-no FCU etc in sight!

2) Shower (20+ years old) meter-6mm tails-switchfuse (35A fuse)-6mm cable-isolator-shower.

3) Bare copper on all Neutral tails at bottom of meter i.e. suppliers and pared up consumer unit and switchfuse unit tails.

Label on top of meter saying "Inspected by (name) in 2003" lol

Tails and install been there a lot longer than that I know

Regards and thanks for any help

 

[ban-all-sheds]

1)This sounds like it is supplied from the shower circuit, would everybody agree?-no FCU etc in sight!

Might be.

Nothing wrong with that, necessarily - they might have implemented my design...

 

[securespark]

But it should be fused down....he said no FCU.

 

[ban-all-sheds]

no FCU etc in sight

//www.diynot.com/forums/viewtopic.php?t=20386

 

[kai]

My shower and fan are supplied as follows.

Off the 30mA RCD side of the main CU, a B40 breaker feeds a mini 2way CU in the back room, which also has a 30mA RCD as a mainswitch.

The mini CU has a B40 breaker for the 8.5kw Shower, plus a B6 breaker for the fan circuit, which goes to a 3amp fuse-connection unit for the fan.

The shower side goes to a 63amp DP isolator outside the bathroom door, and then into the shower.

It's safer to have two 30mA RCD's in series, one backing up the other - feels more safe that way!

 

[Clitheroe]

Afternoon Everybody

Thanks for the ideas and help

Clitheroe wrote:
1)This sounds like it is supplied from the shower circuit, would everybody agree?-no FCU etc in sight!

Might be.

Nothing wrong with that, necessarily - they might have implemented my design...

But it should be fused down....he said no FCU.

Clitheroe wrote:
no FCU etc in sight

Yes I see what you mean. I have to say though that if there is an FCU etc anywhere it will have to be inthe attic above. I will be returning again so I might have a look next time.

Regarding the tails, has anybody ever seen this before, I'm sure I've heard someone mentioning a similar situation another time?

Regards

 

[jason1958]

> It's safer to have two 30mA RCD's in series, one
> backing up the other - feels more safe that way!

Departure from BS7671 noted on EIC & CU "Additional Screwups" section

Better to spend the money on an RCD tester, eg, Suckit & See.
Test buttons do catch most "fail non-safe", but not all failures.
Test button usage also avoids "stiction" that can develop.

 

[ban-all-sheds]

>
>

Try the quote button...

Departure from BS7671 noted on EIC & CU "Additional Screwups" section

In what way is it a departure?

 

[jason1958]

Departure from BS7671 noted on EIC & CU "Additional Screwups" section

In what way is it a departure?

Two 30mA RCDs in series do not provide discrimination.
That is to say, without one being type-S, both may trip on L-N imbalance.

 

[securespark]

Also, the two MCB's don't discriminate.

 

[ban-all-sheds]

Two 30mA RCDs in series do not provide discrimination.

Which reg says they have to?

 

[ColJack]

536.3?

OR

531.2.9?

 

[ban-all-sheds]

Where's the danger?