2391-20 anyone else doing it

[kablue2000]

Hello everyone,

I started the 2391-20 design and verification on monday ,is anyone doing this course

 

[Apache]

Hello everyone,I started the 2391-20 design and verification on monday ,is anyone doing this course

Why - were you on your own? Did you get the right night?

:coat

 

[kablue2000]

Right night wasnt on my own

On this course there is a 20+hour project.If anyone else is doing the course maybe able to share ideas on project

 

[revjames]

Hi there. I also am doiung this course. I started on 2nd Nov and am going back next week (Rotherham) to do the last 2 days. I am hoping to make a start on the project this weekend. Yes it would be great to discuss it. PM me for an email.

 

[revjames]

hello?

 

[kablue2000]

will be starting probably this weekend or next, been revising for the exam and left the project alone. good luck for later!!

 

[a1]

Why not discuss it on the Board here Gents? After all - That is why I set it all up for you.

Personal details - then fiar enough, PM each other with those.

But With everything else, put it on here and others may benefit or share their experience with you.

 

[revjames]

OK then will do

 

[septiclecky]

Right night wasnt on my own On this course there is a 20+hour project.If anyone else is doing the course maybe able to share ideas on project

Still coming up with that load of rubbish 20 hours for the project more like a 120 hours when I did it.

 

[revjames]

Just sat the exam, think it went Ok but made the mistake of talking to the others afterwards "what did you get for answer number 4?....." wish I hadnt said anything...... Did a cable calc but sounds like I missed something.

rest of it not bad so reckon between 60 - 70% hopefully

 

[kablue2000]

Just sat the exam, think it went Ok but made the mistake of talking to the others afterwards "what did you get for answer number 4?....." wish I hadnt said anything...... Did a cable calc but sounds like I missed something.rest of it not bad so reckon between 60 - 70% hopefully

Im sure i done enough to pass anything more than that would be great.Now for the 2 month wait.now for a stiff drink!!!!!

 

[revjames]

While its a bit fresh in my mind, I will try and recap the Q's:

1 was a metal shed being supplied from a house, how could you supply an earth. a sub q was about the ratio of low energy lights/ total

2 was about a leisure centre, started with something like give 3 reasons why the leisure centre is classed as a special location, some qs about zone 0 lights in the pool etc

3 caravan site

4 cable calc , work out Vd etc, cable size, rating for ambient temp

5 cant remember

6 a q about a HGV yard with pressure washer facilities, IP ratings, type of lighting, wiring systems etc

7 TT system, earth electrode test

8 was a schematic showing TPN switch, Fuseboard, contactor/starter with push buttons and remote stop, TPN switch and a 6KW conveyor. Had to state the types of switching ie isolation, emergency, switching for mechanical maint etc.

9 Ring final - work out what value of L-N at each socket and value of R1+R2

10 question about doing IR tests on a large installation.

 

[kablue2000]

7 earth electrode test using earth loop impedance tester

 

[revjames]

Yes you are right, describe how you would do it - just reworded what was in the OSG

 

[revjames]

Not sure it was using ELI tester? it asked you to describe how you would conduct test and what you would do if the reading was too high...

remembered 3 was caravan site, one q was what type of supply can you not use (TNC-S)

I will include the qs as we remember them in the original post

 

[revjames]

Hi there

I thought I would throw this back to the top. I asked the question below on a different thread but thought I would re post it in this thread since it relates to the 2391-20 course. Don't suppose anyone else doing it?

I'm sure there will be more questions as I go through the project and if you are all OK with it I will keep them in this thread. Thanks in advance for your help and support!

doing some work on my 2391-20 design project. Left it late I know only a couple of weeks left!

My dilemma is this. I am stuck on a question asking me to work out cpc sizes. Before I can get into the s= sq root I2T/K formula I need to work out the cable sizes of the line conductors. I will need this info for other questions anyway.

I am stuck on the grouping factors. My cable (singles PVC) go from DB into PVC trunking and then drop down in PVC conduit to the cooker it feeds.

I make that ref b method. for 1 circuit (ie line and neutral) Table 4C1 on page 268 shows a grouping factor of 1. Thats great but its only on its own while it goes down the conduit (2M) to switch and cooker. What about the Cg factor while its in the PVC trunking with about 100 other circuits?

Please - I would really appreciate some constructive advice!

There was another guy doing this same project but he seems to have disappeared!

 

[revjames]

Anyone?

 

[Zeespark]

Rev, regarding the factors above, I didnt get a chance to get into My college on Wednesday, planning on doing it tomorrow for you bud. Sorry:coat

AndyGuinness

 

[revjames]

Thanks, I really need to jknow this before I do calculations on 36 circuits!

 

[revjames]

As for the title of this thread the answer is obviously NO! I was hoping that there would be others doing the same course on here. Hopefully you guys may find it interesting and as always I very much appreciate and value your input.

I am cracking on with the project - its a big community centre 2 storey, cafeteria with commercial kitchen, offices, 2 ground floor function rooms, 2 first floor function rooms, toilets M & F and disabled, lift, and as theres always a 'special location' issue in these projects - Photo Voltaic arrays on the roof.

Initially there were 3 DBs listed on the plans - 1 on the ground floor and 2 upstairs. Initially I was going to leave it at that and stick PVC trunking everywhere, dropping down in conduit to the various ccts. (bear in mind a lot of this is new to me - I'm ex heavy industry ) I soon found out about Cg - the only one of the 4 factors that applied (no buried cable, no insulation issues and ambient temp of 30C) the one size fits all approach of trunking was prohibitive in that you would have to allow for huge numbers of circuits in the same space and end up with massive cables.

I opted for extra DB in the kitchen/cafe area and an extra one by the function rooms/ toilet area. This drops length of ccts and Cg too.

I have pretty much sussed out most of the cable runs and sizes of sub mains etc and am now looking at a question about PVs on the roof.

I have to select the right equipment based on manufacturers data. I am planning to run the cables from the roof mounted arrays to DC isolator, then into inverter, then into the AC isolator and then into the first floor DB and then (assuming it can share the sub main?) into main CCU and metering. I envisage having metering that counts the electricity used in both directions ie deducts the PV generated amount and credits any unused excess power.

I have found some info online but fairly basic stuff. I need to know what impact it might have for example on the sub main to the DB. electricity will be flowing in 2 directions, I would have thought it would lighten the load if anything??

Any thoughts?