View Full Version : Electrical Safety Check - Criteria?

11-08-2005, 09:22 AM
Hi, I am a new landlord renting an ex council property for the first time in Scotland and would be very grateful for some technical advice if you can spare the time.

I have carried out a Landlords electrical safety check on all the electrical appliances in the flat and also the whole flats electrical circuitry has been checked. This check was carried out by an NICEC electrician.

My problem is that during the check it was discovered that there was no earth supplied to the flat! The power supply is provided to the houses in the street by means of overhead cables rather than underground cables. In the place of the normal earth, we have an RCD trip switch which (I understand, as a complete novice) trips in the event of an overload. He then gave me a report that said the flat had failed the safety check due to the earth problem.

The electrician said that in order to provide me with a report saying that the flat was electrically safe I would need to have an earth supplied to the flat (at no doubt great expense). I called in Scottish power (electricity provider) and they said that the supply was perfectly safe with the rcd switch but if I needed the earth installed anyway there was a long lead time.

AT LONG LAST - MY QUESTION : Is the NICEC electrician correct in that even with the RCD switch installed, legally the flat is still unsafe (the previous owners have lived in the flat for five years with no problems)? Are there any other standards other than those used by NICEC which accept the use of an RCD as normal practice? I don't want to endanger anyone but feel that this might be a money making exercise on the part of the electrician. Any thoughts would be very welcome. Thanks.

11-08-2005, 09:34 AM
This sounds more of a techie question for sparkies then a residental question. Basically you dont need a certificate for any existing electrical work, you only need a certificate for new work carried out within certain criteria, do a search for Part P on this forum. However, you have been prudent and carried out a check and found a problem therefore you will probably have to act on it. I allways go on the www.diynot.com forums for anything to do with techie stuff.

Hope this helps

11-08-2005, 09:40 AM

thanks for your advice. I give that a try.

11-08-2005, 16:50 PM
I'd strongly suggest you ask your query on the uk.d-i-y usenet newsgroup (at http://groups.google.co.uk/group/uk.d-i-y?lnk=lr&hl=en if you don't have an off-line newsfeed) - it's extremely active, full of experts, and I'm sure someone there will have the answer. Alternatively, try the 'talk' forums on www.screwfix.com.

I'd be fairly sure that having RCDs doesn't circumvent the need for an earth, and that your sparks is correct, but don't quote me on that!

11-08-2005, 18:16 PM
It looks like you have what is called a TT supply. The responsibility for providing the earth is yours. To ensure the RCD operates correctly there must be a maximum impedance of 1666 ohms to earth. To ensure safe operation the impedance should be as low as possible, say 10 ohms. Where the supply is TT an RCD is mandatory
The best configuration is a split load consumer unit with a 100mA time delayed RCD main incomer protecting lighting fridge etc. This 100mA unit is upstream of a 30mA RCD protecting sockets etc. This configuration gives overall protection. The equipment on sockets is more likely to cause a problem and would trip the 30mA RCD whilst the lighting circuits remain on.
Installation of an earth rod should not cost a lot (rod about £10). The rod is hammered into the soil as close as possible to the consumer unit. Check there are no underground services before starting. Your electrician should be able to carry out the work in a few hours assuming your consumer unit does not need changing.

15-08-2005, 00:43 AM
Kelly build has answered you. Without being too technical, get your niceic fellow to fit an earth rod (a TT system) is correctly in place. When the loop impedance is measured, the voltage should not go over 50Volts. let him sort the rcd thing out for you. This is a code 1 failure "requires urgent attention" as listed on page 2 of the report. this is a directive from the IEE not the NICEIC. he can only fail the installation on breech of regulations in BS7671, which he has correctly identified.

Be under no illusion, the whoever was there before had no problems, therefore it should be safe! this is a big misconception often suggested by our customers. A bit like a seatbelt.... it is there for when you need it... it doesn't stop the crash.
Hope this helps