electrical terms explained

[sxsparky]

Here is a list i have just copied off my website Teague Electrical - Home

M.C.B. (Miniature Circuit Breaker) Electronic version of a fuse, often called a "trip switch."
​	R.C.D (Residual Current Device) A safety cut-out that will disconnect the power quickly in the event of an electrical fault. often called a "safety cut out switch."
​	R.C.C.B. (Residual Current Circuit Breaker) Same as R.C.D.
	R.C.B.O. (Residual Circuit Breaker with Over current protection) and combination R.C.D. and M.C.B. in a single unit
​	C/U (Consumer Unit) Another name for the Fuse Box. There are commonly 5 levels of consumer unit available to most domestic situations. Each varies in price and have both advantages and disadvantages.
​	1. Dual R.C.D. consumer unit with 2 R.C.D's splitting the property's electrical installation in to 2 sections, if 1 R.C.D. trips only half of the installation will be affected (compliant with BS 7671-2008 17[SUP]th[/SUP] Edition Wiring Regulations)
​	2. Consumer unit with Main Isolator and relevant sized R.C.B.O's (compliant with BS 7671-2008 17[SUP]th[/SUP] Edition Wiring Regulations)
​	3. Split board consumer unit with Main Isolator and required circuits protected by R.C.C.B. (compliant with BS 7671 16[SUP]th[/SUP] Edition Wiring Regulations)
​	4. Consumer unit with combined R.C.C.B. Main Isolator and relevant sized M.C.B's (compliant with BS 7671 16[SUP]th[/SUP] Edition Wiring Regulations)
​	5. Consumer unit with Main Isolator and relevant sized M.C.B's
	P.A.T. (Portable Appliance Testing) What is a Portable Appliance? An electrical appliance may be classed as "portable" if connected to the mains by way of a flexible lead, apart from all the usual types of hand held appliances like drills, hairdryers etc. this also includes TV's, PC's, fridges, printers and microwaves, even hand dryers & electric heaters etc fixed to the wall, are all classed as portable and come under this category.
	Solar PV (Photovoltaic) are panels often fitted to a south facing roof or appropriate surface used to generate electricity, generally in a domestic situation this falls under the title Micro Generation and allows the reduction of domestic electricity bills and if installed by a MCS (Micro Certification Scheme) registered contractor can qualify for cash income under the FIT's Scheme (Feed in Tariff) where you get paid for electricity generated by the electricity supplier (please contact for further information)
​	Final Circuit - A circuit connected directly to current using equipment or to socket outlets
​	M.E.T. (Main Earthing Terminal) A common point of earthing either inside your consumer unit of close by
​	P.M.E. (Protective Multiple Earthing) A common means of main earthing in this area, where the supplier uses the neutral of the main incoming cable (where suitable) as your point of earth.
​	T.T. Earthing System. Where a Earthing spike is used as the main point of earthing, it should be connected to the M.E.T. with 16mm Green/Yellow earthing cable and be clearly identified with a safety warning label.
​	Sheathing. An alternative means of earthing if P.M.E.is not available and T.T.is not suitable, this uses the suppliers cable sheath (where suitable) as the main point of earthing.
​	C.C.U. (Cooker Control Unit) This is the local isolation switch for your cooker, it should be visible and not placed over or above the cooker itself (usually to the side)
​	C.C.O. (Cooker Cable Outlet) This is a wall mounted cable outlet point usually behind the cooker itself, where the cable is connected to the cooker. This allows the cable to be disconnected from the cooker for removal.
​	P.I.R. (Passive Infra Red) Usually a means of switching on external lighting automatically, detects movement which switches lighting on for timed periods, often prone to triggering by animals and trees.
​	BS 7671-2008 (I.E.E. Wiring Regulations 17th Edition) Current standards electricians should work to. Now incorporated into Building Regulations as "Part P".
​	Main Bonding. Means of Earthing all incoming services into the property (e.g. Water/Gas/Oil)
​	Supplementary Bonding. Means of earthing all metallic surfaces in the bathroom/kitchen/shower room
​	Competent Contractor. Registered Electrician with one of four professional bodies who has been assessed as capable to trade in accordance with part P of the Building Regulations and BS 7671 (IEE Wiring Regulations 16th Edition)
​	Notifiable Work - Electrical work carried out at in a dwelling or associated garden, conservatory or outbuilding in England and Wales need to be notified to a building control body, whether independently or through a registered electrical association (e.g. NIC EIC)
​		NAPIT -NationalAssociation of Professional Inspectors and Testers, NAPIT acts as the electrical contracting industry's independent voluntary regulatory body for electrical installation safety matters throughout the UK. It maintains and publishes registers of electrical contractors that have been assessed against Scheme requirements, including the national electrical safety standard BS 7671, the IEE Wiring Regulations.
​		TrustMark is an award-winning scheme supported by Government, building industry and consumer protection groups to help you find reliable, trustworthy tradesmen to make improvements and repairs inside and outside your home.

 

[telectrix]

T.T. Earthing System. Where a Earthing spike is used as the main point of earthing, it should be connected to
the M.E.T. with 16mm Green/Yellow earthing cable and be clearly identified with a safety warning label.

where does 16mm come from???

 

[Engineer54]

Perhaps who ever wrote that, was expecting to always reach sub 1ohm Ra values, where it would be valid. But not when the UK talks in terms of Ra's at 200 ohms!! lol!!!

 

[sxsparky]

Thick enough not to be damaged, is usually 16mm, but if it is buried un-protected, more my be needed.
​

 

[DPG]

Sheathing. An alternative means of earthing if P.M.E.is not available
Being picky but the definition of sheathing is not 'a means of earthing' Daz

 

[Guest112]

bit sketchy on the whole tbh you mentioned pirs mainly being used for outside lighting? most pirs i see are in office environments or in schools inside lol

 

[DPG]

I reckon someone is going to take issue with the earthing/bonding defs also. Don't like being picky, but it's a dangerous game re-writing definitions. Best to go with the official ones I reckon. Daz

 

[sxsparky]

thanks make will change it, I am trying to explain sheathing is normally used to earth in a TN-S

 

[Engineer54]

Sheathing. An alternative means of earthing if P.M.E.is not available
Being picky but the definition of sheathing is not 'a means of earthing' Daz

I think we know what your talking about here, but shouldn't it be the other way around??
ie, ...that PME is the alternative to a TN-S DNO cable sheath earth!! lol!!

 

[sxsparky]

bit sketchy on the whole tbh you mentioned pirs mainly being used for outside lighting? most pirs i see are in office environments or in schools inside lol

Its aimed at my private customers, I agree that where they are mainly seen day in day out to save on energy.

 

[sxsparky]

I think we know what your talking about here, but shouldn't it be the other way around??
ie, ...that PME is the alternative to a TN-S DNO cable sheath earth!! lol!!

Sorry I am trying to explain if there is no (PME) TN-C-S then there normally is a TN-S set up which is normally earthed via the sheath of the incomer cable.

 

[Engineer54]

Sorry I am trying to explain if there is no (PME) TN-C-S then there normally is a TN-S set up which is normally earthed via the sheath of the incomer cable.

And i'm trying to explain that PME is the alternative to TN-S (as well as TT) They can't make a PME system into a TN-S system earth, but they can turn a TN-S into a PME system earth....

 

[Inteificio]

That was an interesting read, I had always wondered what an RCD was.

 

[telectrix]

a few more definitions for DIYers.:


cpc-- a usefull strand of copper wire, used for stripping the sheath off T/E. cut off after use, it don't do anything anyway.

earth-- where you dig a hole to bury your dog after it's pee'd on the socket you fitted without RCD protection or cpc.

switch live-- the black wire that makes the fuse go bang when you've connected it to the neutrals in that light you just put up.

rewireable fuse-- doesn't need fuse wire- a bit of stripped 1.5mm will do and those annoying fuse blows will be history.

Dual RCD CU== what you get from B&Q for £50 , bang it in in an hour. why pay for professional help?

back box-- an unnecessary expense. just dig plaster depth and stick socket/switch in with plaster.

i'll think of some more after another beer.

 

[trev]

How about, Safe Isolation-something that should be disregarded if your customer's scumbag chavvy offspring wants to watch Jeremy bloody Kyle.

 

[ipf]

What about 'Inductive reactance'...banging your head against a brick wall after a 3 hour site induction.

 

[telectrix]

longest site induction i ever had was 2 hours. but that was for 500ft down the salt mine. use of breathing apparatus, escape routes, etc.

 

[Knobhead]

Which salt mine Tel?

 

[ipf]

3.5 hours at Ringway Airport. Working in a cafe/ restaurant miles away from the action. Most of the talk was for folk p****** about on the runways. Film was longer the Sound of bloody music.( singing to myself- 'Let it snow, let it snow, let it snow' with a bit of Bruce Willis)

 

[telectrix]

Which salt mine Tel?

winsford, cheshire.