AM2 Lighting

[Spudnik]

@JASON and @SINTRA

I've already said I will supply the quotes etc...

Please do, as i am genuinely interested.

 

[Outspoken]

wtf are you on about now ???
take your neutrals to a ceiling rose .............. in a commercial ?
lol , you'll find most commercials have grids or banks of flouresents , good luck trying to find a dropped neutral in a room with 30 lights lol.
al li've heard so far is blah blah bad practice blah blah not on my job etc etc.
like sintra said if your cant bring some non-compliance regs to the table your just talking a load of waffle that has absolutley no relevence to standard UK commercial wiring practices........
oh i get it now , the entire contracting industry must be in the wrong because 2 or 3 individuals on here "dont like it"
well im off now gents , good evening to you all.

Biff, you really are a plumber at times, you read what you want into what people say and instead of applying common sense you shoot your mouth off. I have worked in commercial jobs over the years that do not have centralised lighting control systems, they are often called SHOPS, OFFICES (Small) and small Industrial units...have you heard of them..FFS, take your pipe vice out of your arse and remember you are not the No1 sparky in Britain, you have not worked in every installation in the country and neither have I, but I will lay a bet that I have worked in a more diverse range, in more roles and NEVER have I found neutral at a switch in a commercial or industrial installation except where the switch was double pole or it required the neutral for an indicator or sounder.

 

[Engineer54]

As already stated i'm firmly in the against switch looping camp. I'm also very aware of the different wiring systems that other countries use. I can also understand and accept there are situations where a neutral is either required or advantageous. But as far as the UK is concerned with the typical building constructions of domestic houses and small commercial premises, i can't see why anyone would want to loop through switches. your going to end up using more cable for a given installation and could end up fixing switch plates back onto a bed of cables within the back boxes, especially where multi point switch plates are called for.

Things must of changed somewhat since i worked on a large shopping centre in the UK, where just such an example came to light on a sub contract building (basically constructed as a typical 3 storey brick house build).
Came across at least 3 different switch positions on the ground floor with 4 T&E's and 2 X 3 core & E entering the back boxes! Needless to say it was ordered to be all stripped out and wired conventionally on a 3 plate system. The amount of cable used on the rewire, was around 2/3rds that of which was used in the original scheme.

Oh, the 2 electricians that did the original first fix wiring was asked to leave the site, and the electrical sub contractor almost lost his contract.

I can tell quite a few stories about that large shopping centre contract, it certainly opened my eyes in many respects. Even had to go up against the Eastern Electricity Board, that wanted to break a cardinal rule on the MV ring system they were contracted to supply to the project!! lol!!

 

[ackbarthestar]

Utter Gonads.

You would never get away with Neutrals at switches on a commercial or industrial installation regardless of the cable you used.

If you wire in conduit then you use the 2 plate method unless there is a good reason not too, thus no neutral at switch.

If you wire in T&E or any other multi-cored cable then you use the 3 plate method, all neutrals at the ceiling rose/light and the only cables at the switch are a live feed and switch line.

The excuse that it is easier to wire T&E with the neutral loop method holds about as much water as a bottomless bucket, you have to take cables to the light/ceiling rose anyway from the switch, so this is a lame excuse. You should only have one cable at the switch unless it's a multi-gang switch.

It is laziness borne out of bad practice and nothing anyone says here will convince me differently, people are just finding poor excuses to justify what is bad workmanship and sloppy attitude by saying "We don't design and install for safety"...crock of puke.

I don't fully agree with the above statement.

Consider a kitchen with 24 GU10 Halogen/LED down lights. Now ask yourself, where you would like the feed and neutral, what sort of access arrangements might you consider, how you might control the lights in batches of 4, 6, 8 or 12.

On a domestic its open to all sorts of combinations but, let say you were doing a commercial job such as a pub. You would then probably use a grid switch assembly with double pole 20A switches?

@Biff55, Sorry for the reiteration. Just reread your post and you appear to be saying the same as myself

 

[Outspoken]

I don't fully agree with the above statement.

Consider a kitchen with 24 GU10 Halogen/LED down lights. Now ask yourself, where you would like the feed and neutral, what sort of access arrangements might you consider, how you might control the lights in batches of 4, 6, 8 or 12.

Well I would not pull neutrals into the switch as it affords no electrical or practical benefits so your argument is pointless. As for siting any connections, a lot would depend on the specific situation and the construction of the premises.

On a domestic its open to all sorts of combinations but, let say you were doing a commercial job such as a pub. You would then probably use a grid switch assembly with double pole 20A switches?

@Biff55, Sorry for the reiteration. Just reread your post and you appear to be saying the same as myself

Why would you use DP switches? I appreciate you can, and there are occasional situation where this may be advantageous, but the overwhelming majority of installation this would be impractical and you would use a shed load more cable than required. The simplest way in such a situation would be single pole lighting contactors in their own enclosure adjacent to the DB and the contactor coils switched via the normal light switches...so again, not neutral at the switches. I have used and spec'ed this method in numerous installations.

 

[YoungBart]

From the AM2 guide

"As a part of the new AM2 exam you will have to wire up a 2 way and intermediate lighting circuit
with one light. To do this you must memorise the wiring diagram from below and follow it on the
day of the exam.
You will use 1.5 mm2 twin and earth cable and “push in” terminals to connect the wires together
where needed.
Your first cable will go from the CU to the nearest switch where you will connect the brown (L) to
the common (C) terminal. Your next length of cable will run from here to the last switch with the
brown wire not in use and the blue (N) and green-yellow (E) connected together with the first
lengths blue (N) and green-yellow (E) inside the first switch using the “push in” connectors. Next is
a length of cable from the first to the intermediate switch connecting together the L1 of the first
switch with the L1 of the intermediate switch and the same for the L2 terminals. You will use the
brown wire for the L1 to L1 connection and the blue wire to the L2 to L2 connection. Very
important is to mark the blue wire with brown slewing because it will be a Line conductor! Repeat
this step from the intermediate switch to the last switch.
For the last part you will need a length of cable from the last switch to the light. On one end the
brown wire (L) will go to the common (C) terminal while the blue (N) and green-yellow (E) needs
to be connected with the other cables blue (N) and green-yellow (E) using “push in“ connectors.
The other end of the last cable connects to the appropriate connectors in the light.
Since the whole installation is located in front of you it will be very easy to work with the short
lengths of cables."

my understanding is that that is wrong, due to the light being switched from the first switch as well as the feed, I think I saw the same info on sparky facts and that's what threw me, hence the OP

 

[Fast&Rough]

If I can I allways loop in at the switch.

 

[Engineer54]

Why would you use DP switches? I appreciate you can, and there are occasional situation where this may be advantageous, but the overwhelming majority of installation this would be impractical and you would use a shed load more cable than required. The simplest way in such a situation would be single pole lighting contactors in their own enclosure adjacent to the DB and the contactor coils switched via the normal light switches...so again, not neutral at the switches. I have used and spec'ed this method in numerous installations.

We use the French/German impulse relay system for such situations. I really don't know why more use of this type of system isn't used in the UK!!

 

[Sintra]

my understanding is that that is wrong, due to the light being switched from the first switch as well as the feed, I think I saw the same info on sparky facts and that's what threw me, hence the OP

Here is a link to the complete pdf that includes drawings.

https://www.dropbox.com/s/4yr5j9c6o4fohe5/AM2-Guide1.pdf

 

[Outspoken]

We use the French/German impulse relay system for such situations. I really don't know why more use of this type of system isn't used in the UK!!

It's all much of a muchness, the single pole dedicated lighting contactors are highly reliable, can switch loads, in some cases, up to 63A and they are "off the shelf" and relatively cheap so they tend to be selected.

In a recent building I did see impulse relays being used in conjunction with a Lutron Lighting controller and that was a pretty need combination of the two systems in a warehouse where they wanted lights to be off most of the time, but for walkways to illuminate as people walked or took F/L Trucks down them, but as the lights were a mixture of fluorescent floods and metal halides they clearly decided the controller was unable to handle them directly so connected via the relays to avoid inrush issues, likely from the halides.

 

[rmc86uk]

wtf are you on about now ???
take your neutrals to a ceiling rose .............. in a commercial ?
lol , you'll find most commercials have grids or banks of flouresents , good luck trying to find a dropped neutral in a room with 30 lights lol.
al li've heard so far is blah blah bad practice blah blah not on my job etc etc.
like sintra said if your cant bring some non-compliance regs to the table your just talking a load of waffle that has absolutley no relevence to standard UK commercial wiring practices........
oh i get it now , the entire contracting industry must be in the wrong because 2 or 3 individuals on here "dont like it"
well im off now gents , good evening to you all.

So you've never installed a Klik plug and socket or seen one in a commercial install?

 

[Outspoken]

So you've never installed a Klik plug and socket or seen one in a commercial install?

Biff probably thinks the 4th terminal in a Greg (Plug in rose) is the Neutral and everyone who uses them for E-Lights is being naughty!

 

[Engineer54]

If I can I allways loop in at the switch.

Your handle suits you to a tee then!! lol!! :dunce:

 

[Fast&Rough]

Just incase I need to spur off the switch for an extra socket

 

[Outspoken]

I have been having a hunt for anything that relates to this subject, finally I found this quote..

Except where there is a requirement a neutral should not be passed through or terminated at a switch point

Now this is not a regulation, only guidance toward CIBSE Engineers, or at least those who follow CIBSE Guidances so this is not definitive at all, but clearly one of the respected bodies has given this due consideration and decided there is a good reason to NOT pull Neutrals into switches and neither to terminate them there.

Thats good enough for me, as well as 30 years experience