A few questions...

[brightspark19]

Hiya. After a test & inspection on a property I've been asked to sort the remedials to get it up to scratch. Just wanted to get a couple of answers on a few of them.


code:1 - 16mm main tails are fused incorrectly at 100A

Would upgrading them to 25mm tails be alright or do I also need to fuse it down to 80?

code:2 - No supplementary bonding in bathroom

I didn't think we did this any more? Is it back in place for 17th now?

code:2 - No 'r1' reading obtained from circuit and no (r1+r2) or Zs reading - socket circuit.

?


Any help would be appreciated. There are also some code:4's but I won't bother with those unless it's something worth doing - IE something that will actually make a difference to the people living there as opposed to 'no earth sticker' etc.

Cheers.

 

[JohnnyG]

code:2 - No supplementary bonding in bathroom

I didn't think we did this any more? Is it back in place for 17th now?

It's not 'back in place' in fact I don't think it was ever left out as such but to omit it you have to meet certain conditions -

For new installations or alterations / additions in a location containing a bath
or shower, supplementary bonding will not be required if:

 The disconnection times required by Section 411 of BS 7671 are met,
and
 All circuits are protected by RCD’s having the characteristics required
by 415.1.1, and
 The building has protective equipotential bonding in accordance with
411.3.1.2, and
 All extraneous-conductive parts of the location are effectively connected
to the protective bonding. (See note below)
Note: Regulation 415.2.2 states that where doubt exists regarding the
effectiveness of supplementary equipotential bonding, it shall be confirmed
that the resistance R between simultaneously accessible conductive parts
and extraneous conductive parts fulfils the following condition:
R ≤ 50V / Ia for a.c. systems
By example, using a 30mA RCD (Required by 415.1.1)
R ≤ 50V / 30mA = 1667 ohms
Where supplementary bonding is required, Regulation 701.415.2 requires
that the protective conductor (cpc) of each circuit entering the room
containing a bath or shower, be connected to the extraneous-conductive
parts by local supplementary equipotential bonding conductors complying
with Regulation group 544.2.
This is carried out to prevent the occurrence of voltages between any such
parts being of such magnitude as could cause danger of electric shock.

 

[Spark123]

Hiya. After a test & inspection on a property I've been asked to sort the remedials to get it up to scratch. Just wanted to get a couple of answers on a few of them.


code:1 - 16mm main tails are fused incorrectly at 100A

16mm tails are rated at 87A method C, 25mm are rated at 114A

code:2 - No 'r1' reading obtained from circuit and no (r1+r2) or Zs reading - socket circuit.

It means the line is not a ring on the phase conductor i.e. there is a break in it somewhere. The Zs can't be calculated using normal methods and there is a risk of overloading one of the conductors in the circuit.

 

[mikhailfaradayski]

It means the line is not a ring on the phase conductor i.e. there is a break in it somewhere. The Zs can't be calculated using normal methods and there is a risk of overloading one of the conductors in the circuit.

?

 

[Spark123]

r1 is the continuity of the line (or phase) conductor on a ring final circuit.
You can work out Zs by (r1+r2)/4 and adding Ze providing all sockets are on the ring, you should see approx the same value of (r1+r2)/4 at all sockets on the ring when tested. Spurs will have a higher resistance, the highest one of which is recorded and added to Ze to give Zs.

 

[mikhailfaradayski]

sorry - yea, i understand what r1 is (and r2 and rn as it appens), i just didn't understand the way you wrote it. Maybe im not reading properly today? i know im struggling with speling..

Who mentioned a ring circuit?

 

[ban-all-sheds]

code:1 - 16mm main tails are fused incorrectly at 100A

Would upgrading them to 25mm tails be alright or do I also need to fuse it down to 80?

If they are the ones before the meter they can't be replaced by anyone except the DNO.

Nor can the fuse.

 

[brightspark19]

OK so will RCD protecting the bathroom be sufficient or will i have to get a bit of 4mm to every bit of metal in there, nice and neatly of course.

And I'll check all the socket connections, hopefully one will be loose an I won't have to put a new leg in anywhere.

Cheers for the help so far lads.

 

[1john]

How do you plan on RCD protecting the bathroom?

 

[mikhailfaradayski]

OK so will RCD protecting the bathroom be sufficient or will i have to get a bit of 4mm to every bit of metal in there, nice and neatly of course.

yip, don't forget to bond the chains for the plugs to the sink and bath...

And I'll check all the socket connections, hopefully one will be loose an I won't have to put a new leg in anywhere.

Cheers for the help so far lads.

don't want to be rude, but are you a sparky?
Do you have a copy of the current regs?
Why can't you use the regs to find the answers to your sup.bonding needs?

 

[brightspark19]

Yes I am a sparky, and no I don't have a copy of the regs.

And yeah I'll remember to do the chains for the plugs aswell, you funny funny man.

 

[mikhailfaradayski]

ooh, thanks

 

[scousespark]

You have been asked to do remedial work, but don't know what is required. Then you quote the following

Yes I am a sparky, and no I don't have a copy of the regs.

Words fail me

 

[1john]

have got got any way of testing and cert-ing your remedial works?

 

[brightspark19]

I had to give back my copy of the regs when i got laid off because it belonged to them, and haven't been able to afford to replace it since. It's pretty far down my list of things to buy because I'm planning on getting out of this country asap. I'll be able to borrow a set of meggers, that is also fairly far down my list, partly because ive done hardly any testing.