Changes in the 17th edition....

[spark-doctor]

hi guys an gals
what's phase sequencing about?
big al

In what context? A bit more Info please.

 

[Shakey]

hi guys an gals
what's phase sequencing about?
big al

presumably you mean the requirement to verify that the phase sequence is maintained?

dont know what level you are at (so i will assume you dont know)

in a three phase sytem, each phase is angularly 120 degrees apart. the order that these phases 'peak' in (their waveforms) is the phase sequence

in old money, this was conventionally Red-Yellow-Blue, or L1, L2 L3.

The requirement is to verify that if it starts in that order it should finish in that order, with the main problem of motors running in reverse DOR if it doesnt.

 

[bigal]

Thanks for getting back guys
Context is 2 fold: 1) PIR certificate askes for 'verification of phase sequence' What's the test process for this?. 2) reg 612.12: 'For multiphase circuits, it shall be verified that the phase sequence is maintained'? Is this a good enough explanation?
Cheers in anticipation of your replies.
big al

 

[Shakey]

Thanks for getting back guys
Context is 2 fold: 1) PIR certificate askes for 'verification of phase sequence' What's the test process for this?. 2) reg 612.12: 'For multiphase circuits, it shall be verified that the phase sequence is maintained'? Is this a good enough explanation?
Cheers in anticipation of your replies.
big al

common mis-conception Big Al, it says VERIFY, not test.

If i look at one end of a run of SWA,(for example)
and the conductors are labelled, and connected to L1, L2 and L3, and i look at the other end, and they are the same, then i have verified that the phase sequence is maintained. Of course you could do a live test (f you have phase sequence or phase rotation on your meter), you could also dead test (by doing R1+R2 checks on each relevanet phase) or just look as i have said

 

[Tapouchoke]

hi guys new mamber

just had ahalf day vistit with nic went well no departures ist over for 12months now glad found the fourum

tapout

 

[bigal]

Thanks Shakey
I was fearing it to be more complicated than it was.
I think I was just a little 'phased' by the sequence of events.
Cheers
bigal

 

[brook]

What do you have to do with your 16th edition testers??
I need to purchase one and the little man in the shop said that he had no 16th edition ones in stock and he was waiting for the 17thedition ones to come in.

---------
Brook

Sreevysh Corp

 

[andy pandy]

Re junction boxes, their is a regulation somwhere that says a tool is required to remove the lid. This outlaws the old jb`s with the lids that screw on whith out screws.

 

[spark-doctor]

I know of no regulation that says a JB requires a tool to open it

The new JB from Hager just snap close

 

[professional]

The 17th Ed requires you to verify the phase rotation (or sequence) on the part of the system upon which you are working. Newer testers have this facility BUT voltage testers are already available that have this facility built in (albeit a cut down version) for about £30-£40 so don`t ditch your 16th Ed test equipment, there`s nothing wrong with it, just buy a small tester for the odd occasion you need to work on three phase.


If anyone`s interested I can sell them a single phase rotation tester for £200.

 

[city spark]

leeroy,

it is what it is

all sockets 20A or less to be an RCD, unless you had a single socket with 'freezer only' written on it

The ordrinary/skilled persons bit is awkward - lets be hones you are NOT gonna get away with that in a house.

Anyway, its irrelevant because all cables less than 5 cm from the surface have to be RCD protected if insalled in the safe zones and not in earthed metallic conduit.

So Tony are you saying that if your supply cable to freezer is not sunk more than 5 cm or earthed conduit the it must be protected or is this still an exception

 

[professional]

There seems to be some confusion with regard to the requirements of the 17th Ed.

The 16th Ed required rcd protection of any 13A socket outlets supplying equipment outside the EBZ.

The 17th Ed requires rcd protection of ALL 13A socket outlets. In addition, the 17th Ed requires the protection of CABLES BURIED <50mm WITHIN THE FABRIC OF THE BUILDING. There are a few exceptions, one of which is socket outlets for specific pieces of equipment - but the requirement for the protection of the cable remains, hence the earthed mechanical protection or surface mounting methods can be employed, rather than removing the majority of the wall to sink a cable >50mm.

 

[mdes]

well nothing has changed regarding junction boxes, the same rules apply, they must be accessible for maintenance and inspection etc etc

Check out the new ashley brochure it would let you think otherwise

 

[Kris]

leeroy,

it is what it is

all sockets 20A or less to be an RCD, unless you had a single socket with 'freezer only' written on it

The ordrinary/skilled persons bit is awkward - lets be hones you are NOT gonna get away with that in a house.

Anyway, its irrelevant because all cables less than 5 cm from the surface have to be RCD protected if installed in the safe zones and not in earthed metallic conduit.

You can use MI or SWA instead of conduit if you want but who the hell is gonna wanna do that. Can you imagine the customers face when you give him a quote to rewire his house in pyro!

 

[professional]

Check out the new ashley brochure it would let you think otherwise

Well they would say that wouldn`t they.

 

[accable]

What you have got to realise is that they get you 2 ways when installing a socket in a dwelling.
1. Installing the cable, if you use twin & earth then it if it’s less than 50mm deep it must be in the prescribed zones plus RCD protected. To avoid RCD protecting the cable it can be pyro, armoured or to BS 7436 (it looks like FP200 but its not) you could also run the cable in earthed conduit.
2. Then there is the socket, to avoid using an RCD you could suitably label the socket say “freezer only”
Tonyc

 

[welshmadness]

Had a good argument with a "know it all"kind of guy the other day, he reckoned that you did not need to use RCD protection if you used metal capping to protect the cables run in walls. Managed to convince him otherwise.

 

[accable]

Hi welshmadness

You are quite right, metal capping is to protect the cable from damage that could be caused by the plasterers trowel.

To provide mechanical protection to comply with regulation 522.6.6 (iv) you would require metal plate at the very least 3-4mm thick and then that will not provide you protection from shot fired nails.

Tonyc

 

[dkent5]

17th edition test equipment.....Ha ha ha ha ha ha ha....oh my word!......hee hee ho ho!
A superb marketing technique to take cash off the unwitting.

I get my multitester Fluke calibrated every year at the same place and even they're not dumb enough to try and sell me one of these new 17th bits of kit.

 

[Plan]

The only difference I can see between 16th & 17th edition testers are the multi function all in one testers that download all fixed info onto computer then generate cert from that. The prob is the change in zs values. Before buying new kit it maybe (?) possible to get hardware upgrade from manufacturer website

 

[scotsparky]

I know of no regulation that says a JB requires a tool to open it

The new JB from Hager just snap close

Have a look at 416.2.4 in BRB

 

[Plan]

As for metal capping I've known 20mm galv conduit flushed in wall (and bonded) for a elec cooker, client didn't want cooker on rcd cos of damp in elements causing nuisence tripping, he gets a LOT of dodgy cookers in his properties!

 

[matthunt]

As a matter of interest to people taking or about to take their 17th Edition course, all final circuits now have a maximum disconnection time of 0.4 seconds (i.e. lighting circuits)as per table 41.2, however table 41.4 allows for 5 second disconnection for circuits down to 6amp, please read regulation 411.3.2.3 in conjunction with this table as this table is for Distridution circuits, (Sub-Mains). Most will be aware of this but some during revision will overlook.

 

[Mark2009]

Thought I'd start a sticky post on the 17th edition changes, basically just list of all the regs which have changed, be as detailed as you like really, hopefully it'll become a decent reference post for you look upon in the furture months before it comes into action. Type away...........

Hi
20A Breaker for Sockets with RCD this is only if its a Radial, A Ring i would still use 32A with RCD from what i know all sockets will be Radial very soon to keep in with Europe.

Thanks

Mark

 

[Sparky198421]

Thank You All

 

[anil]

thank you]Thought I'd start a sticky post on the 17th edition changes, basically just list of all the regs which have changed, be as detailed as you like really, hopefully it'll become a decent reference post for you look upon in the furture months before it comes into action. Type away...........[/QUOTE]