AM2 - My Experience

[SparkyChick]

Hi all, I've just taken my AM2 and figured I'd post some information and advice.

First up, if you get offered a Pre-AM2 session by your training provider... take it. Go along, make copious notes and pay attention. I learned an awful lot about it.

Composite installation (8.5 hours)

You have to install 7 circuits as follows:-

• Carbon monoxide detector - FP200 cable from DB to FCU in dado, then glanded out onto cable tray (bolted P clip fixing), glanded into detector mount
• Lighting - T+E from DB to first 2 way switch, 3+E to intermediate switch, 3+E to last switch (all in dado), T+E in trunking up to light. Note - The supply goes to the first switch, then the 3+E carries two switched lines, the neutral and CPC until the final switch
  
• Ring circuit - Singles from DB to 1st socket, then to SFCU, then to last socket and back to DB and singles from SFCU to spur socket (all in dado/conduit)
• TP+N 16A Socket - XLPE SWA from DB to isolator (fixed to tray with tie wraps), singles from isolator to socket
• Motor circuit - Singles in metal trunking to DOL starter then SY to motor, tie wrapped to tray
• Heating - Singles in metal trunking to SFCU
• Cat 5 data connection - Cat 5 cable from one outlet to another, all in dado

You also have to install the right protective devices and the bonding to gas and water (these will be run in trunking and then tie wrapped to tray).

And the final part (which may fill you with dread) is the heating system.

You get clear wiring diagrams that tell you exactly what protective devices to use for each circuit and which phase they are connected to. The diagram also tells you exactly what type and size of cables to use.

My tips...

• Read the diagram and the information thoroughly before you start. Some cable sizing info is on other documents, but it is all there
• Follow the steps as laid out in your candidate manual with one exception... do the heating last as most of it is simply following the wiring diagram and connecting it up to the wiring centre (which is a big set of DIN rail mounted Wago spring clamp terminals) That's not to say there isn't wiring to do, but it's a total of 13 cores in singles (from solar controller to circulator - 3 cores LNE, from wiring centre to room stat - LNE Lreturn, from wiring centre to programmer - LNE Lr1, L2, Lr2)
• There isn't too much thinking ahead needed, but do look at the tray that the bonding will be mounted on... there will be two sets of cables on that tray... the SY and the bonding... you don't want them to cross
• When running the ring, check the cable sizes for the heating circuit... mine were the same size so I ran the feed to the heating SFCU in at the same time
• When running the singles in... get all the cores you need together (if you need to use multiple cores of the same colour - like in some of the heating connections, mark them with insulating tape on the start of the core and the reel). Tape them together and run them in. You should be able to run them all in without using a fishtape except for the run from the programmer to the heating wiring centre
• When running in the ring... tape the cores of legs together at each termination point, especially at the DB
  
• Don't forget to sleeve conductors
• If you do forget something, make a note of it and go back to it
• If you've never worked with FP200, don't worry too much, it's not too bad. Doesn't bend easily and the sheath is quite tough. To strip it, run a knife round the sheath and then bend at the cut and the sheath should begin to split
• If you've never worked with SY cable, go to a local supplier and pick up a couple of metres and a set of CXT glands and practice (you peel the braid back, split it and wrap it into two tails one on either side of the central core - these go into slots on the gland to be sandwiched and secure by two large flat washers, wrap them around and cut them off when they reach the other slot, don't let the braid tails stick out the washers)
• Be careful with the SWA, SY, FP200 and Cat5 cable - You get one shot as you are supplied with precut lengths, so measure carefully
• Don't worry about dressing cables too much... BS7671 does not require the board to be a master piece of cable dressing, chuck it in... if it works properly it doesn't matter if it's messy (I cut one segment of my FP200 a bit short of it looked awful in the DB but wasn't under strain and so was compliant)
  
• Do worry about excess copper on display
• Don't overtighten things - They undergo a lot of abuse, something I learned early on when I broke a screwdriver blade
• Don't leave the lamp in the luminaire - As above, it's had a lot of abuse and the clips that normally retain them nice and tight are like to be crap (I know this because mine fell off and smashed on the floor)
• Keep your work area tidy - When the cover comes off the board set it to one side, slightly open, take the dado covers off and stack them behind the board cover, take the metal trunking lids off and stack them on top of the trunking. Keep the tools to one side so you don't trip over them
• Don't be afraid to use the AVIs at the centre during the installation phase if you want to check something (identify a cable for example if you didn't mark it with tape), confirm this with the assessor obviously, but they are there for you to use

Don't let the apparent scale of the task worry you. Working methodically and following the steps in the candidate guide I was able to complete the installation with over 2 hours remaining. Some of which I used to double check things.

Fault Finding (2 hours)

You have to find 7 faults. You have to work through them in order and you have to have an attempt at each before moving on.

My tips...

• Look at each fault and think about it for a short while and use the definition to pick the right gear
• Remember that there are only certain locations faults can be (because they have to conceal the cabling that creates the faults - i.e. it can only be inside the trunking and any box marked 'Candidates must not open/remove') - So if you get a fault on the 16A socket outlet... the location can only be after the isolator, since the supply is run in SWA from the DB to the isolator
• The types of faults are breaks, misconnections, shorts or high resistance connections
• If insulation readings were difficult to obtain, don't forget to check N-E

Be thorough and logical.

For each one, you have to provide a brief description of the fault, the location and the fix. Here's an example for a fault on the ring circuit...

• Fault is a short circuit between neutral and earth
• Location is between SFCU and dado socket
• Fix is run new earth/neutral cables from SFCU to dado socket and retest

The last bit (and retest) is an absolute must in every fix. And that's it.

I had a data cabling misconnection, a high resistance connection on a bonding cable, a couple of neutral earth faults (shorts), a phase earth fault (short), a broken cable and another I can't remember

Again, being logical and methodical about it, you should be able to complete this quickly. If you don't have a lot of experience with fault finding, try and get some before the event. The trickiest thing I guess if you're not that experienced is finding faults on ring finals. If you've got say a neutral/earth fault, how do you find it... well, you pick a point which is roughly central on the ring (in this instance it's easy as it's socket - sfcu - socket, but in reality it can be a guessing game) and then you split the ring (disconnect the conductors at fault at that point) and test each half. You should find the fault is on one half, so you split that half in half and test each half and so on until you find leg of cable with the fault on it. For things like breaks or high resistance joints on rings there are other approaches that can yield a result faster, but if in doubt (certainly for IR and breaks) splitting the ring will yield results quite quickly.

The gear I used during my fault finding session... insulation resistance tester, continuity tester on the MFT, AVI with continuity indicator and a data cable tester.

Risk Assessment and Short Safe Isolation of Board (45 mins)

The risk assessment part... don't go mental on this. The instructions are clear, risk assess the assessment centre. So as an example... you don't need to talk about respiratory protection as you're not going to be cutting board or drilling holes. On the day I did mine though, it was raining heavily and the floor is painted... slip hazard from a wet floor that could affect anyone entering the building, can be mitigated by putting a suitable mat down

Safe isolation of the board... standard procedure... but for gods sake don't forget to ask the client if you can turn the power off (I did, but remembered and pointed out my mistake).

 

[SparkyChick]

Safe Isolation of Circuits (30 mins)

You have to isolate under three scenarios...

• Replace the luminaire
• Work on the DOL starter
• Work on the board

In this case, you don't have to worry about asking permission because you've been instructed to turn the power off (at least that's what my assessor advised after the event).

So for work on the circuits... do not open the board or any accessory, turn off, lock off, open a point suitable for testing (the luminaire and starter as appropriate), prove the AVI, test, prove the AVI again. Done.

For the lighting circuit... (1) = First 2 way switch, (2) = Intermediate, (3) = Last 2 way switch - switch them in this order (starting with them all in the same position).... (1), (2), (3), (1), (2), (3), (2). I got the AVI setup for a connection (L-N for example) and then did the switch cycling, next connection (L-E) switch cycle and so on.

For the board, turn off, open the board, lock off (you can't open the board with the lock off device in place), prove the AVI, test at the load side of the main switch, prove the AVI again. Done.

Inspection and Test (3.5 hours)

• Polarity - So normally when I'm installing, I use R1+R2 and measured Zs to prove polarity on circuit... for this, you're going to calculate Zs. If you read GN3, visual inspection and R1+R2 is an acceptable method of proving polarity, so when the candidate guide gets to the Polarity section, it's talking about supply polarity.
• Insulation Resistance - Couple of points here
  • Items sensitive to IR checks - Most are obvious, but the RCBO protecting the ring final may not be... when preparing for your IR tests, the neutral and functional earth leads should be disconnection and the RCBO should be isolated from the board (the boards we had were Merlin Gerin Isobar I believe) these have slides that cover the incomer terminal screws of MCBs etc. and connect that slot to the relevant bus bar (don't forget to slide these over when you install the devices)
  • Global check - Turn every circuit MCB on and the TP+N socket isolator, do a global test from the load side of the incomer (remembering to remove the neutral link to avoid a neutral earth fault from the TNCS supply), then check the SY cable from the motor test points. If all is good every single reading should be maxed out
  • Ring final check - Disconnect the circuit from the RCBO, turn on the SFCU for the spur and test that circuit on it's own
  • Lighting circuit - Lots of strappers here, so use the same switching cycle as for safe isolation
  • I got asked how I was going to do it before hand and I explained... global check, then I'm going to test the lighting circuit and the ring final, so 3 stages.
• R1+R2 - You must check this at every point. For the 16A socket, check it at the incomer of the isolator, turn the isolator on and then use the socket adapter to check it at the end. For the motor circuit measure from the DB to the isolator of the starter and then from the output of the starter to the motor and add the results together to give you a value for the circuit
• Ze - Take three readings (L1, L2, L3) record the highest value
• Zs - Use the highest Ze value and use this to calculate Zs for each circuit (put 'Zs by calculation' in the remarks)
• The paperwork - Don't leave anything blank, don't forget to fill in the boxes for number of schedules of inspections and number of schedules of test results and don't forget to fill in the Page x of x values

General points... be very careful with this section. It is one of the few where you are observed fully and it's very important that you listen to the assessor and read the instruction manual carefully. Although it's not written, it was said that when I had completed my visual inspection I should call the assessor... I missed that bit and narrowly avoided having to redo some work. So listen and read carefully. You should also read the instructions carefully for a few points where you will be asked to verify things... this typically takes the form of writing something on the back of the schedule of test results (things like RCD disconnection times, formula's used etc.).

If you find yourself getting flustered, trust me there is plenty of time, so take a step back, take a deep breath and gather your thoughts. You can reference the OSG, GN3 and BS7671 at any time during this, so if you're unsure about a test procedure, grab GN3 and read it. Nearly all of us have a copy of GN3, BS7671 and the OSG we keep in our vans (I know I do) and they are there for a reason... there is a lot to remember and much of the exams etc. is not so much about remembering it, it's about knowing where to find it.

General Tips

• Insulation resistance testing and safe isolation checks - Single phase L-N, L-E, N-E (3 tests), Three phase L1-N, L2-N, L3-N, E-N, L1-E, L2-E, L3-E, L1-L2, L1-L3, L2-L3 (10 tests) - You must demonstrate these and believe me the assessor will be counting
• Lighting circuit switching - You must switch them in the order specified above and retest after each switching operation
  
• Take your time but don't dawdle along, keep your eye on the time but don't panic about it either. It's plenty of time for each section
• If you find something is broken... tell the assessor, he will stop your clock and get it sorted (during fault finding for example, once I had identified the fault, the location and the fix, the clock was stopped and I was able to restore the rig to full operation before starting the next fault - this included remaking some terminations that were seriously mangled - at which point, the clock was started again when I was ready)
• Phase rotation checks - If you've never used one, look up how to use a phase rotation tester
• You cannot take anything into the room with you apart from a jacket, glasses and a drink (which must not enter any of the bays), so travel light
• Stay calm - The pressure I was feeling got to me on a couple of occasions. Upon reflection I think it was exacerbated by the fact that I wasn't using my tools (I spend money on good tools and equipment to make my life easy - the tools and gear at the centres get abused big time and as such are not the best). I had problems with R1+R2 testing on my two way lighting circuit (I was getting open circuit when it should have been connected and all sorts which I think was down to poor connections on the test leads because functionally it was perfect when it was finally tested - you must test it with the switching order used for safe isolation) and loop impedance tests for my Ze (readings were inconsistent, they seemed to randomly vanish as though the MFT thought I'd finished and sometimes it failed to test at all, plus there was a wait time when I first connected like it was doing something)

And that's it from me

Suffice to say, I passed and because I worked in a steady methodical manner, had the luxury of finishing in 2 days. It's intense and I'm not afraid to say I was absolutely bricking it on Tuesday morning before I started (not helped because I got lost and started worrying I wasn't going to make it in time - so, find out where your centre is and take a drive there so you know where you're going... if you're doing it at this time of year, take a drive in the dark because you'll be arriving before the sun comes up).

Good luck with it when you take it. It's a hard slog but when you've done, it feels awesome

 

[gazdkw82]

Brilliant post and extremely helpful to me, I have AM2 coming up in next few months

 

[Silly Sausage]

Very good, SC!

With all the recent chatter about SY cable being of dubious compliance, why are they testing you on installing it?

 

[westward10]

Brilliant SC.

 

[SparkyChick]

Very good, SC!

With all the recent chatter about SY cable being of dubious compliance, why are they testing you on installing it?

Thank you.

I asked that exact question about SY cable during the Pre-AM2 day... the answer was it's in the test I think because when this version of the test was created it was deemed acceptable.

 

[JAWS]

You watch YouTube you may follow the odd electrican on Instagram or Twitter but for me Sparkychick is one of these inspirational persons who especially the likes of me a Trainee wants to one day emulate.

 

[westward10]

You watch YouTube you may follow the odd electrican on Instagram or Twitter but for me Sparkychick is one of these inspirational persons who especially the likes of me a Trainee wants to one day emulate.

Even the pink bra

 

[SparkyChick]

I've received a few comments that my posts make it seem like there is a lot to do and consequently they are making people worry about it more.

Let's be clear... this assessment is not meant to be a walk in the park. It is one of the final parts of an apprenticeship/adult training program (yes, technically I'm a trainee, currently doing my Level 3, NVQ3 and the AM2) and is designed to establish whether you are up to the task of working unsupervised with the end goal being a safe, regs compliant installation that meets the specification provided. It's not about designing the installation, it's about installing it, testing it and finding faults on it.

I'm not going to sugar coat it, you should be worried about it.

I was doing electrical and electronic design/production/installation work at various levels (some of this professionally) for over 30 years before I became a boil in the bag sparky by going on a short course and setting up my business just over two years ago. Since then I've done lots of installation work, lots of fault finding and lots of testing. Do I feel confident doing this? Absolutely. Was I worried about the AM2? Hell yes!

I was feeling physically sick at the start of the first day because I understand how important this assessment is. Did I have some panic moments during my AM2? Absolutely. Some of my testing didn't go well (I'm used to my Megger MFT and how it operates so using the Kewtech MFT was to say the least... an experience... not one I want to repeat anytime soon), my safe isolation for work segment... took me 3 goes to get the first one right... I nearly blew it because I just couldn't wrap my head around it. And I found myself getting very irritated at the tools provided because they aren't my usual gear (I typically use two sets of pliers on site... my Knipex installation pliers and a pair of Knipex side cutters... on the AM2 I was using three sets, constantly changing, my drivers are all CK and clearly marked so I can find them quickly... I spent what felt like a disproportionate amount of time searching for the right driver).

It's not a walk in the park and I'm not trying to make it seem thus, but by sharing my experiences (and some of the information I received during my Pre-AM2 day and some nuggets I picked up during the event) I'm trying to help you prepare for it by knowing in advance what's expected (so you can practice and learn the bits you need to and benefit from the insight of someone who's been there).

I can't stress this part enough (it's not something I've seen in anything I've read about the AM2 and it wasn't mentioned before hand)... the candidate guide tells you exactly what to do and what is expected from that stage (yes you may have to read diagrams for a little information about cable sizing etc.), but for the most part the candidate guide is your bible. Read it, understand it, and then follow it (leaving the heating till last). Work at a consistent, steady pace but don't rush, because rushing = mistakes.

 

[SparkyChick]

You watch YouTube you may follow the odd electrican on Instagram or Twitter but for me Sparkychick is one of these inspirational persons who especially the likes of me a Trainee wants to one day emulate.

Don't really know what to say to that other than thanks

 

[gazdkw82]

I've received a few comments that my posts make it seem like there is a lot to do and consequently they are making people worry about it more.

Let's be clear... this assessment is not meant to be a walk in the park. It is one of the final parts of an apprenticeship/adult training program (yes, technically I'm a trainee, currently doing my Level 3, NVQ3 and the AM2) and is designed to establish whether you are up to the task of working unsupervised with the end goal being a safe, regs compliant installation that meets the specification provided. It's not about designing the installation, it's about installing it, testing it and finding faults on it.

I'm not going to sugar coat it, you should be worried about it.

I was doing electrical and electronic design/production/installation work at various levels (some of this professionally) for over 30 years before I became a boil in the bag sparky by going on a short course and setting up my business just over two years ago. Since then I've done lots of installation work, lots of fault finding and lots of testing. Do I feel confident doing this? Absolutely. Was I worried about the AM2? Hell yes!

I was feeling physically sick at the start of the first day because I understand how important this assessment is. Did I have some panic moments during my AM2? Absolutely. Some of my testing didn't go well (I'm used to my Megger MFT and how it operates so using the Kewtech MFT was to say the least... an experience... not one I want to repeat anytime soon), my safe isolation for work segment... took me 3 goes to get the first one right... I nearly blew it because I just couldn't wrap my head around it. And I found myself getting very irritated at the tools provided because they aren't my usual gear (I typically use two sets of pliers on site... my Knipex installation pliers and a pair of Knipex side cutters... on the AM2 I was using three sets, constantly changing, my drivers are all CK and clearly marked so I can find them quickly... I spent what felt like a disproportionate amount of time searching for the right driver).

It's not a walk in the park and I'm not trying to make it seem thus, but by sharing my experiences (and some of the information I received during my Pre-AM2 day and some nuggets I picked up during the event) I'm trying to help you prepare for it by knowing in advance what's expected (so you can practice and learn the bits you need to and benefit from the insight of someone who's been there).

I can't stress this part enough (it's not something I've seen in anything I've read about the AM2 and it wasn't mentioned before hand)... the candidate guide tells you exactly what to do and what is expected from that stage (yes you may have to read diagrams for a little information about cable sizing etc.), but for the most part the candidate guide is your bible. Read it, understand it, and then follow it (leaving the heating till last). Work at a consistent, steady pace but don't rush, because rushing = mistakes.

Didn't realise you was on a NVQ sparkychick?

I'm doing mine too. Nearly finished, at Leicester college

 

[SparkyChick]

Didn't realise you was on a NVQ sparkychick?

I'm doing mine too. Nearly finished, at Leicester college

Yes, since I started the business with my clutch of boil in the bag qualifications I've been looking to try and get the level 3, AM2 and NVQ3 sorted so I can officially call myself an electrician

Got a phone call out of the blue from a local training provider... want to do your NVQ and AM2? Yes please, how much and what's the catch? Free to you Madam as the Welsh government are paying and there is no catch. Hell yes please

So, I've taken all the level 3 exams and passed them, have obviously completed the AM2 so it's literally just my NVQ portfolio which I'm going to write up over Christmas, the on site visits and a written project that are standing between me and a gold card... Hallelujah!

 

[gazdkw82]

Yes, since I started the business with my clutch of boil in the bag qualifications I've been looking to try and get the level 3, AM2 and NVQ3 sorted so I can officially call myself an electrician

Got a phone call out of the blue from a local training provider... want to do your NVQ and AM2? Yes please, how much and what's the catch? Free to you Madam as the Welsh government are paying and there is no catch. Hell yes please

So, I've taken all the level 3 exams and passed them, have obviously completed the AM2 so it's literally just my NVQ portfolio which I'm going to write up over Christmas, the on site visits and a written project that are standing between me and a gold card... Hallelujah!

Who is doing your portfolio?

We have JLS and they are not very good

 

[SparkyChick]

I have a tutor from the college to help me.

 

[Silly Sausage]

the answer was it's in the test

There's no real argument with that with the examiner!

 

[brucey2343]

Hi, thanks again for the awesome post. I have a question though, when doing the global IR, you have to isolate the RCBO. Does this mean simply removing all cables and turning it off, or do you have to physically remove the RCBO from the board?

 

[SparkyChick]

On the boards in the test centre I went to, it was a Schneider or Merlin Gerin board that had isolators on the bus bar lugs, so for the global IR test, you disconnect the RCBO fly leads and slide the isolator to disconnect the device from the busbar.

I think it's an Isobar board, or something like that.

 

[telectrix]

SC's posts are extremely informative and I admire her for posting. that lot would have taken me 6 months just to type it.

 

[Pete999]

On the boards in the test centre I went to, it was a Schneider or Merlin Gerin board that had isolators on the bus bar lugs, so for the global IR test, you disconnect the RCBO fly leads and slide the isolator to disconnect the device from the busbar.

I think it's an Isobar board, or something like that.

A daft question SC, forgive me but if you operate that slide, do you not dis the circuit as well? or have I missed the point?

 

[SparkyChick]

RCBOs can be damaged by IR testing, so when you're doing the global IR test (to save much time), you isolate the RCBO from the rest of the installation. In a domestic board you'd technically have to remove the device from the board and disconnect it's fly leads, but in the Isobar boards, you isolate the device and disconnect the fly leads. Then, reconnect it, disconnect the load and test the RFC on it's own.