IET logo
 
IET
Decrease font size
Increase font size
Topic Title: 2396-2012 PROJECT
Topic Summary:
Created On: 17 March 2012 04:41 PM
Status: Post and Reply
Linear : Threading : Single : Branch
<< 1 2 3 4 5 Previous Next Last unread
Search Topic Search Topic
Topic Tools Topic Tools
View similar topics View similar topics
View topic in raw text format. Print this topic.
 30 July 2012 04:00 PM
User is offline View Users Profile Print this message


Avatar for Jobbo.
Jobbo

Posts: 913
Joined: 08 July 2010

Haha, very good

Good good John, I'm glad the spurring on helped! Let's hope our friend enjoys reading them

Regards

Jobbi
 14 November 2012 02:50 PM
User is offline View Users Profile Print this message



Dans2382

Posts: 1
Joined: 14 November 2012

Hi Jobbo and John.....(I was on the course with you)

Finally delivered my project couple of weeks ago... I said I was a bit worried about the time scale but they said I was fine!

Glad to see the back of it... hope all is well.
 22 November 2012 03:36 PM
User is offline View Users Profile Print this message


Avatar for B67BU.
B67BU

Posts: 76
Joined: 07 March 2012

Good luck to everyone who is sitting the course next week in Birmingham

-------------------------
Why don't you rock down to Electric Avenue (Birmingham B6 7BU) And then we'll take you higher.

B67BU@ElectricalTraining.co.uk

 22 November 2012 04:54 PM
User is offline View Users Profile Print this message



alanblaby

Posts: 373
Joined: 09 March 2012

That's reminded me, has my project been assessed yet please John?
I dropped it off at the end of June, did the exam in March.
Also, it looks like I'll be doing your PAT course between Christmas and New Year, would that still be going ahead if only a few register?
(or maybe it is a busy week, where anyone who works is able to get to you?)
Thanks
Alan.
 23 November 2012 11:18 AM
User is offline View Users Profile Print this message


Avatar for briggsy6.
briggsy6

Posts: 495
Joined: 24 September 2003

It was marked in September, Alan. (passed, btw). We'll chase up C & G for you. That next course you're on? I'm off that week!
 04 March 2013 09:06 AM
User is offline View Users Profile Print this message



GaryHurn1

Posts: 3
Joined: 06 April 2010

i have just started my time off work, in which i hope to get the project done and handed in. i did the exam last May (2012) but due to working away and then travelling around australia (has been booked for 4 years) time is ticking fast before the 12months limit we were given runs out, so i am locking myself away for a week or so and trying get it sorted. i am trying to pick up where i left off, i just hope i dont go into too much detail that wastes time for no real gain.

what is the avearge people have spent from start to finish on the project??the 40hrs seems very optimistic
 04 March 2013 01:32 PM
User is offline View Users Profile Print this message


Avatar for OMS.
OMS

Posts: 19671
Joined: 23 March 2004

Certainly most people I know who have undertaken the project have spent about 120 hours on it - and probably about another 40 or so making mid course corrections when elements of the initial design solution have proved challenging in practical design - typically things like grouping factors when faced with a single tray or trunking run are difficult to resolve so a multiple run approach then required takes quite a bit of re design effort (drawings, circuit lengths and containment sizes then all have to change. Equally, "circuiting up" causes a few dramas when doing the lighting in terms of circuit load and probable phase allocation.

There are loads of areas where either a lack of design experiece or access to your tutors causes a lot of work that's "abortive".

Equally, you should also look for "similarity" betwen aspects of the questions - helps you avoid producing two sets of calculations showing similar things when one set showing everything is easier - spreadsheets are ideal for this task as you can selct what you want to produce from a single "model".

Remember that design is iterative - you go so far, hit a problem, make corrections and recycle it into a new solution - that's where the time goes.

Good luck

OMS

-------------------------
Failure is always an option
 04 March 2013 02:55 PM
User is offline View Users Profile Print this message



GaryHurn1

Posts: 3
Joined: 06 April 2010

thankyou for the advice
 04 March 2013 09:02 PM
User is offline View Users Profile Print this message



Zs

Posts: 2909
Joined: 20 July 2006

Look at your grouping factors and do not go below 50%. In my case that meant confining myself to about 8 circuits per lump of trunking.

Diversity, Diversity, Diversity.

I smiled my way into Argos with a Clamp meter. Went home and diversified some more.

You can do it.

Zs

Edit: Gary, Are you working on Johnston's Catalogue shop? I thought that had expired and been replaced so i doubt it. I will not give you any answers because that is not fair on those of us who cracked on in an OMS stylee (ref the funky new avatar) and presented on time and did it on our own, but I will give you some helpul googles to save you some time, in public. If you are stuck, then move on to the perifery questions and get googling as a break from the circuit questions.

Google 10kW PV array, Shropshire, and PV array calculator. I have just given you a present.

Edited: 04 March 2013 at 09:15 PM by Zs
 05 March 2013 09:47 AM
User is offline View Users Profile Print this message


Avatar for Parsley.
Parsley

Posts: 1007
Joined: 04 November 2004

I haven't seen this project, there are probably a few circuits that are loaded at less than 30% of their grouped current rating and therefore can be ignored from the overall grouping factor as per note 9 from table 4C1.

Regards
 05 March 2013 11:58 AM
User is offline View Users Profile Print this message


Avatar for OMS.
OMS

Posts: 19671
Joined: 23 March 2004

Originally posted by: Parsley

I haven't seen this project, there are probably a few circuits that are loaded at less than 30% of their grouped current rating and therefore can be ignored from the overall grouping factor as per note 9 from table 4C1.

Regards


That's the skill of the designer to ensure that selected circuits don't exceed 30% of grouped rating - particularly lighting circuits when contrasted against mitigating inrush current operation of CPD's.

I'm not sure if this is offered by tutors, but certainly it doesn't come naturally to the candidates - although with a bit of prompting the mists clear and, when the rationale is understaood, it saves hours of grief for the candidate

Regards

OMS

-------------------------
Failure is always an option
 05 March 2013 12:27 PM
User is offline View Users Profile Print this message



GaryHurn1

Posts: 3
Joined: 06 April 2010

im slowly getting there just finihsed the solar pv part of it, now back on to the circuit designs...... gave myself a break this morning after spending 10hrs yesterday on them.

some good points above,cheers

Gary
 05 March 2013 12:45 PM
User is offline View Users Profile Print this message


Avatar for Parsley.
Parsley

Posts: 1007
Joined: 04 November 2004

Originally posted by: OMS

Originally posted by: Parsley



I haven't seen this project, there are probably a few circuits that are loaded at less than 30% of their grouped current rating and therefore can be ignored from the overall grouping factor as per note 9 from table 4C1.



Regards




That's the skill of the designer to ensure that selected circuits don't exceed 30% of grouped rating - particularly lighting circuits when contrasted against mitigating inrush current operation of CPD's.



I'm not sure if this is offered by tutors, but certainly it doesn't come naturally to the candidates - although with a bit of prompting the mists clear and, when the rationale is understaood, it saves hours of grief for the candidate [IMG][/IMG]



Regards



OMS


And there's also non-simultaneous overload, which seems to be quite common in B&D world.

Regards:
 05 March 2013 12:51 PM
User is offline View Users Profile Print this message


Avatar for OMS.
OMS

Posts: 19671
Joined: 23 March 2004

And there's also non-simultaneous overload, which seems to be quite common in B&D world.


For sure - what we call non conurrent diversity.

Start with a supply capacity that the builder can afford - design to suit that (backwards) - apply diversity at any point you like - if it doesn't "fit" apply more diversity until it does - simples

Regards

OMS

-------------------------
Failure is always an option
 22 March 2013 06:29 PM
User is offline View Users Profile Print this message



Corbil

Posts: 3
Joined: 30 July 2012

Finished task A and c but task b the only question i have not done is about PV installation how much in depth have you got to look into it.
 25 March 2013 11:31 AM
User is offline View Users Profile Print this message


Avatar for OMS.
OMS

Posts: 19671
Joined: 23 March 2004

Originally posted by: Corbil

Finished task A and c but task b the only question i have not done is about PV installation how much in depth have you got to look into it.


Well as the exam is an exercise in BS 7671, then concentrate on that bit - look at various guidance notes that discuss small scale embedded generation

Understand the basic implications of what 10kW means in terms of current and what impact that has on DNO agreement to connect to networks - can it be made much simpler if you take an alternative approach. How bick would a 10kW array be - if you stick it on the roof will there be impacts on bonding for your TN-C-S system and or lightning protection systems

Emphasise volts "drop"(technically rise) within your cabling - ditto arrangements for isolation

Discuss also what implications the PV has on assumed maximum demand of the installation - back to diversity again I guess

Basically, read the question word for word and answer that.

Regards

OMS

-------------------------
Failure is always an option
 25 March 2013 12:13 PM
User is offline View Users Profile Print this message



Corbil

Posts: 3
Joined: 30 July 2012

Thank you
 16 July 2014 01:09 PM
User is offline View Users Profile Print this message


Avatar for dannydore.
dannydore

Posts: 5
Joined: 12 July 2013

Hi all. Been reading a lot of topics in regards to grouping factors, none of which seem to have the exact answer I'm looking for.

I'm currently in the process of doing a project for my 2396 Design & Verification course which is a 2 storey college block. I'm using metal trunking (method B) and pvc 70Âșc singles (Table 4D1). There are 3 runs of trunking which encompass the whole building, 2 for the ground floor, and 1 which rises to the 1st floor. My grouping factors are 0.47 (11 circuits) for both of the ground floor runs, and 0.43 (14 circuits) for the 1st floor run.

After doing all of my Lighting circuits, I came to the Power calculations. Obviously, these grouping factors applied to a 20a Ib (or In) produces ridiculously high Iz (or It) figures (10mm to be precise).

"Use Note 9", I hear you say... Well, even after changing all of my lighting circuits to 2.5mm, only 6 circuits were lightly loaded (2 on each run) Thanks to the Guilds for making the majority of the lighting fluorescent/discharge with a 1.8 factor.

As the drawings merely show twin s/o's, I have no idea what the actual uses are for each circuit, and I would actually prefer to use the correct figures found in the Regs.

The only solution I can see is changing all of my containment to either add another trunking, or a completely different installation method. But seeing as I've had these all printed out on A1 scaled drawings, I'm a bit reluctant to do so. Also having worked on site for 4 years or so, I (and no doubt every other commercial/industrial spark) have seen trunking runs stuffed to the brim. Something just doesn't add up!

Am I missing something here, or can anybody suggest an alternative?

Thanks
Danny
 16 July 2014 01:27 PM
User is offline View Users Profile Print this message



AJJewsbury

Posts: 11467
Joined: 13 August 2003

Sounds familiar. Did you not like the answers you got from your original thread? http://www.theiet.org/Forums/f...id=205&threadid=58451
- Andy.
 16 July 2014 01:38 PM
User is offline View Users Profile Print this message


Avatar for dannydore.
dannydore

Posts: 5
Joined: 12 July 2013

Originally posted by: AJJewsbury

Sounds familiar. Did you not like the answers you got from your original thread? ">http://www.theiet.org/...s/f.....eadid=58451

- Andy.


As sympathetic as it was, I didn't see any real solution in your reply Andy. There seems to be a lot of people discussing the 2396 project in this thread, so it seemed appropriate to post the message here also.

Thanks anyway
IET » Wiring and the regulations » 2396-2012 PROJECT

<< 1 2 3 4 5 Previous Next Last unread
Topic Tools Topic Tools
Statistics

See Also:



FuseTalk Standard Edition v3.2 - © 1999-2014 FuseTalk Inc. All rights reserved.