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Re: Electrical Safety & Legal Legislation
Squadman
I think it is well worth having. Make sure you get the 2nd edition (published 2001). From what I remember its about £25 😕
The Wiring Regs are about £40. The On-site guide is about £20. Both these have data related to Zs (Earth Fault Loop Impedance). It is important to have these limits since if Zs is high the householder will need to have it attended to.
You get all these documents from RS Components or direct from the IEE. Take a look at http://www.iee.org.
AS you are aware, if Zs is high this impacts disconnection time (under fault condition) & could present fire or shock hazards. Alternatively, if you know a friendly electrician & he has Amtech FastTest, he can download ref sheet 1 which has a handy guide of the limiting values for Zs. Use the 80{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} limit (NICEIC recommended) as this will take into account measurement errors etc.
Let me know if you want or need further help.
Have fun!! 🙂
Re: Electrical Safety & Legal Legislation
Squadman
Quote’ Where do the previously mentioned figures of . 2 M ohm or . 3 M ohm fit into this criteria. My concern when testing is to ensure my own safety and that of my clients. Few if any of us are likely to be qualified as electricians and do not profess to be ! likewise the electrician would not be able to perform our role. Therefore my tests ensure that there is an good earth present and that the appliance passes my earth and contunity tests as given. ‘ unquote.
The 0.2Mohm value is normally (in fact the wiring regs state 0.25Mohm) taken as a minimum allowable insulation value for a 230V installation. It is recommended that insulation values (for a 230V installation) below 2Mohm are investigated.
Remember that the Earth Fault Loop Impedance values & limits arise from various tables in the Wiring Regulations. As I understand this, the EFLI limiting value is dependent on fuse/mcb type, cables and disconnection times (just to mention a few parameters).
The 0,3Mohm value arises from appliances with elements greater than 3kW(as previously stated in earlier mail).
Hope this helps.
Re: SMEG SUK91MFX broken oven
If you are not qualified or you have doubts, you should get an engineer to take a look. The engineer will also carry out safety tests using equipment you are unlikely to have.
If you decide to try to do it yourself, make sure the local switch is off as well ensuring the MCB is turned off or if a fuse, it is removed :zap:
My advise to you,is, if you have any doubts, get someone in to do this for you. As mentioned before, you can find someone through the Repairs@module on this website.
Regards
Re: SMEG SUK91MFX broken oven
More than likely the element. The oven normally slides out from the front.
If you need an Egineer, take a look at the Repairs@module.
Re: Electrical Safety & Legal Legislation
Martin
I note your conclusions with interest.
I agree with your conclusions about allowing elements to’dry-out’. From what I remember about the ‘early days’, it was common for high power mineral insulated elements to absorb moisture. Running them for about 30 secs allowed them to dry out. Also, if the mineral insulation was kaput, it would trip the fuse/mcb/rcd.
If you look back through the forum, you will see there are many supporters of allowing elements to dry out. Let me say now, I agree with you. If its bad when its cold. Its bad.
Quote ‘1.0 megohm is also far too high (maybe should read low?) but fortunately these days most RCD based consumer units would blow anyway by then! ‘This could be marginal. This represents 23mA (at 230V) if we assume pure dc resistance. Now depending on loss capacitance of the cables & leakage impedance of the circuits connected to the RCD sub-main switch, you can find that the RCD will trip anywhere from 22mA up to 33mA. Also, keep in mind that appliances are not always connected to RCDs. The Wiring Regs only calls for ground floor socket outlet circuits, external sockets, garages & the like to be connected to an RCD.
RCDs should not be relied upon as primary protection in the majority of cases. RCDs are normally considered as supplementary protection (of course, there exceptions like TT supply configurations etc). Most common protection is EEBAD. So, again, Earth Fault Loop Impedance plays extreme importance in ensuring that fuses & MCBs open within the required time (normally 0.4 secs or 5 secs). Hence my stance in using the appropriate tester instead of the test plugs.
Let me take this opportunity to wish everyone a happy & prosperous new year.
Regards
Re: Electrical Safety & Legal Legislation
Martin
Take a look at the IEE Code of Practice for In-Service Inspection & Testing of Electrical Equipment page 43, 15.5, table 2. 0.3Mohm applies to Class 1 heating equipment with a rating of equal to or greater than 3kW. For all other Class 1 equipment 1.0Mohm.
The 18kg defines portability – see page 15, 5.1, equipment types.
Generally, insulation values are defined by the equipment power not weight.
Regards
Re: Your reccomendations on putting drier outside?
Please keep in mind that electrical installations in sheds, outhouses and the like are notifiable under Part P of the Building Regulations as from Jan 2005.
Re: Electrical Safety & Legal Legislation
Earthing is considerd a consumer responsibilty by the supply authorities. I have had occassions where an earth has been provided by the energy supplier only to find that the Ze (External Earth Fault Loop Impedance) is still high due to a supply cable sheath failure. Even so the supplier has refused to change to a PME configuration (for lots of different reasons). Keep in mind that pre1967 main earthing was achieved by connection to the water pipe. This was stopped in in approx ’67 because of the introduction of plastic water pipes. Earthing failures or no earth only shows up when we go do a repair call or someone gets a zap! As correctly stated, ‘my electrics are okay ‘cos it works…….’
The only way round this is to use earth rods, 100mA RCD as a main incomer and use a 30mA RCD on the socket outlet circuits etc.
In my view as shown above) always use a loop tester. These plug-testers often use low test currents & could give inappropriate readings.
Anyway enough preaching from me on Boxing Day.
Only remains for me to wish everyone a happy & prosperous new year!!
Re: SMEG SUK90MFX Tripping RCD
Shirl
This does seem to be an insulation failure. Letting it dry out is an option. If it still trips, have an engineer carry out a 500V insulation test on the element. You can get an engineer thru’ the repairs@ module.
Merry xmas etc..
Regards
Re: Awkward Customers
Dave
Thanks – at least I won’t have to waste time & spend time driving & parking etc at the court doing the paperwork.
Before I forget, a happy xmas & a healthy, prosperous new year to all within UKW
Re: Electrical Safety & Legal Legislation
You do not have to be Part P ‘approved’ to carry out tests. You only have to be Part P’ed if you carry out installation works in certain areas of a house.
As mentioned, do carry out tests. If there is a problem, it is likey that the IEE Code of Practice for In-Service Inspection and Testing of Electrical Electrical Equipment will be referenced.
Also, I believe the HSE issued advisory notes that are available. These were sent out by DASA to members by DASA a few years ago.
I would also advise the use of a proper Earth Fault Loop Impedance Tester as for non-RCD circuits, the test current is around the 25-amp value & will properly ‘exercise’ all connections and cables around the P-E route.
Re: Flu Jab?
Yes. I suffer from asthma. The one year I did not have it, I was off sick for nearly six weeks in total. Also have one for pneumonia as well.
If you can get one have it. It does seem to help.
Re: Awkward Customers
Had a nasty one turn up. Did some work for a customer – quite bit of work on multiple items. Final bill came to just under £200. Paid up by cheque. Keep in mind nice house, nice car, well spoken, even nice kids. Absolutely over the moon with the work carried out. Promised to recommend me to her friends etc.
Cheque bounced 😈 Been trying to get my money for a month – phone calls & warning letters. Now having to do this one through the small-claims court 😡
Re: CDA 906ss – Bottom oven not heating
More than likely the fan element has failed.
Make sure the plug and /or power is disconnected before attempting repair :plug: :zap:
If you need parts, I’m sure that the Parts section of UKW can help.
Failing that, get an engineer through the Repairs@ moduleRegards
