"Lightman" wrote:

The new Housing Act (shortly to take effect in a few days) meant that
I had to have two of my properties which are let as student houses
(HMO's) have their fixed wiring tested (so that I can now pay the
council a further £ 600 per property to register as a
landlord!!......something I have been doing since 1998 (with very
satisfied tenants who never leave).............it's all bureaucratic
nonsence really!!!)

I had NICEIC electricians inspect the wiring and issue PIR certificates

My perfectly safe and very new wiring (which I did myself 3 years ago)
failed on one small point (in both houses). It failed as you
......"need a protective device for each ring main circuit".

Well you cannot really "fail" a PIR you can however get a report that
advises that work needs to be done, or even describes the installation
as "unsatisfactory". Ultimately it is up to you whether or not you
carry out the suggested work. On the other hand if something dangerous
was discovered during an inspection then a responsible electrician
should either make it safe or disconnect the circuit concerned.

Of course if anything goes wrong and you were aware there were
problems, then there could be serious consequences. Your Local
Authority or insurance company will probably insist on a "clean"
report where rented property is concerned anyway.

What I did is to put 2 small ring mains (two adjacent ground floor
rooms) into one 32amp MCB. This meant there was 4 tails in one 32 Amp
MCB. Each ring main is small and has 4 sockets and covers a very small
area. (It was done as rooms were renovated one after another and was
easier to wire like that. I combined some rooms on the ground floor as
the house has about 15 rooms (so I didn't want 15 ring mains with
15MCB's!!!!!!!!).

Well if you had fifteen ring circuits then you would normally put in
fifteen MCBs to protect them. I agree however that it would a very
large or unusual installation if it required so many ring circuits.

That said assuming your design calculations and circuit diagrams
showed fifteen ring mains then there is no problem.

(You did show this documentation to the inspector, didn't you)

Speaking personally for a moment. If I encountered an installation
designed as you describe then it would raise a few doubts in my mind
as to the manner in which it had been designed and installed. I do not
mean that I would automatically assume it to be faulty or unsafe, I
would just expect to find a few unexpected "features" along the way. I
would definitely ask to see the design documents and circuit diagrams,
if any.

The NICEIC electricians informed me that if (they) put a joint box
behind the consumer unit (there is an access hatch) and make one larger
ring main (with 8 sockets) it will then comply!!

This sounds like they suggested turning the two small rings into one
large one and avoiding any potential hazard. This sounds like a
sensible solution.

What nonsence I say!!

Ah you disagree.

These wiring regulations would mean an increased
the length of the total ring main, increase the impedance and would
make it (slightly) less safe (not more!!). I really can't see that it
makes any difference! If you use the MCB as a "joint" it is not
allowed but "out of sight joint box " behind the consumer unit which
doubles the length of the ring main makes it comply!!

OK. Firstly the increased length and impedance would have to be within
the parameters specified by the regulations. Given your description of
the ring circuits to be combined, I doubt that this would have any
noticeable effect on the safety of the circuit.

"Hiding" a junction box behind the consumer unit does not sound like a
good idea. There would however probably be sufficient space inside the
consumer unit to link the two rings with appropriately sized
connectors.

Secondly they noted this as a "dangerous fail". I can't see how it
could be any worse than "not up to current wiring regulations". I can
possibly see that it is unsafe in any way as the MCB is 32 Amps which
is fine for each individual ring

Well there is a potential safety risk here, but it's a slight one. The
four cables associated with this MCB might be seen as a ring and two
spurs and tested accordingly. This would not pick up an open circuit
on one of the rings. A slight risk as I said.

Had I tested this installation I would have noted the unusual design
in the inspector's report. I don't think I would have flagged it as a
safety issue, but without seeing the installation it's hard to make a
judgment.

Certainly this would be something that an inspector would expect to
see and then query on the circuit diagram.

Interestingly enough, this seems to be allowed with the lighting
circuits!!! It seems that one can shove in as many 1mm tails in those 6
Amp breakers as you like!!

Within reason. Again if you had an excessive number I would have put a
comment in the inspector's report.

Any comments from anybody?? I'm jolly interested to see what the group
think!! ......and I especially want to hear from NICEIC electricians!!

Well I'm an electrician who specialises in inspection and testing, and
the above are my comments. I'm not however NICEIC registered.

Best regards - Lightman
(now a qualified PAT tester with 96.666% in that stupid City & Guilds
test which is also a bureacratic waste of time but saves on PAT testing
fees!!!!)

Good man - You now just need to buy a PAT tester and all the other
bits and pieces that go with it.

A tip: The HSE seem to be red-hot on asset registers and retest
periods at the moment.

John
--
John White,
Electrical Contractor