SWA question

[louisIV]

I just did an informal test in my 2330 course for the 205 module exam. One question was this:

At what depth should an SWA cable be buried:

a)600mm from top of cable to ground level

b)600mm from bottom of cable to ground level

c)150mm from top of cable to ground level

d)150mm from bottom of cable to ground level?

Assuming that we're concerned with safety issues here, B) and d) make no sense due to varying sizes of cable and c) sounds very shallow. I'm guessing a), but I can't find anywhere that specifies a particular depth. Does anyone know where I can find the regulations regarding depth of burial of SWA?

Ta. L IV

 

[M107]

522.8.10

I'd go for A

Somewhere I've got a load of regulatory depths of cables when buried under roads/paths/farm land etc.. If I dig it up I'll post it later.

 

[a1]

It is indeed A.

600mm from top of SWA to the level of the ground.

I am 100% Certain of this.

But I am trying to think of the book that it is in. OSG, maybe?

 

[louisIV]

Right - 522.8.10 of the 17th Ed. Regs says:

"Buried cables, conduits and ducts shall be at a sufficient depth to avoid being damaged by any reasonably foreseeable disturbance of the ground."

Nothing more specific than that though ...

 

[philbas]

705.522

For Agricultural and Horticultural premises.

 

[Lurch]

There used to be a specified depth for cables, but as above, it's now up to the installer to specify a suitable depth. There may be minimum depths under certain circumstances, e.g. roadways would be down to whoever wons the road etc.., but the question doesn;t ask about that. I'd not answer it as no answer is correct so you can;t actually get a mark for it anyway.

 

[sparkytim]

There used to be a specified depth for cables, but as above, it's now up to the installer to specify a suitable depth. There may be minimum depths under certain circumstances, e.g. roadways would be down to whoever wons the road etc.., but the question doesn;t ask about that. I'd not answer it as no answer is correct so you can;t actually get a mark for it anyway.

:red card

Very helpful advice

 

[Lurch]

:red card Very helpful advice

It's half a question without no correct answer, what else can you do?

 

[septiclecky]

It is indeed A.600mm from top of SWA to the level of the ground.

I am 100% Certain of this.

But I am trying to think of the book that it is in. OSG, maybe?

If I remember you posted on here sometime back a picture with all the depths for cables gas services etc

 

[louisIV]

There used to be a specified depth for cables, but as above, it's now up to the installer to specify a suitable depth. There may be minimum depths under certain circumstances, e.g. roadways would be down to whoever wons the road etc.., but the question doesn;t ask about that. I'd not answer it as no answer is correct so you can;t actually get a mark for it anyway.

Ah. Perhaps this was a 16th Ed. question that hasn't been modified for the new regs then. Way to confuse a poor student. Or at least fill up valuable study time. headbang

As this is not a formal test, I'll answer a), and query it in class next week.

Thanks once again for your advice guys. And on that subject, are there any women on this board? We've got one girl on the course and around forty blokes. Not a very even balance. Oh well, here comes Saturday night :Y

L IV

 

[philbas]

It's half a question without no correct answer, what else can you do?

I agree, there is no correct answer, unfortunatly that is not one of the options.



In terms of passing the exam I'm pretty sure answer A is the one that will get the mark.

I can find three references to depth in the regs, apart from the general one in 522.8.10.

705.522 Agricultural and Horticultural premise Require a depth of 0.6m

708.521.1.1 for Caravans/Camping Parks etc. Require a depth of 0.6m

709.521.1.7 Marinas SUGGEST a depth of 0.5m

It's interesting that the threat of banging a tent peg down more than half a metre seems to carry more weight than a plow digging it up.

There may be more references to depth, these are just the ones I've found.

Please dont get me wrong, all the regs queted are from the special locations section, and i agree that the situation needs to be assed on its merits, but in term of getting the point in an exam its hard to arguee against A.

Edit: Opps lots of reply while I typed

 

[louisIV]

705.522 For Agricultural and Horticultural premises.

Hey Philbas. Yes I see - 0.6m in that case - refering to cables "with added mechanical protection." Perhaps that's what the question is about, even though the reg. isn't specifying SWA.

 

[philbas]

Hey Philbas. Yes I see - 0.6m in that case - refering to cables "with added mechanical protection." Perhaps that's what the question is about, even though the reg. isn't specifying SWA.

As I understand it SWA is added mechanical protection, I'm usre the more experinced members here will correct me if I'm wrong ; \

 

[louisIV]

522.8.10I'd go for A

Somewhere I've got a load of regulatory depths of cables when buried under roads/paths/farm land etc.. If I dig it up I'll post it later.

That would be most excellent, sir.

 

[Lurch]

I agree, there is no correct answer, unfortunatly that is not one of the options.

Although it has since been confirmed this probably an old paper I still wouldn;t answer a question that has no correct answer anyway. You might as well make up answers for random questions and then let people guess as to what you might be thinking the answer might be in order to get marks.

If something is wrong, don;t bend over and take up, stnad up for yourself!

 

[Andy™]

:red card Very helpful advice

his reply was correct.

 

[louisIV]

As I understand it SWA is added mechanical protection, I'm usre the more experinced members here will correct me if I'm wrong ; \

Absolutely mate. Something I don't know is whether SWA is the only type of cable with added mechanical protection used underground. If so, option a) was a true answer (given 705.522). The test question was either poorly worded or out of date. If it were an official exam I would have selected a) ; you've got to be in it to win it. But as it was just an informal thang, I'll question it in our next theory class.

Sun's over the yard-arm. I'm going to crack open a bottle of plonk. Cheers everyone! :Applaud

 

[philbas]

[quote name='Andy

 

[philbas]

Sun's over the yard-arm. I'm going to crack open a bottle of plonk. Cheers everyone! :Applaud

Crack one open for meGuinness

 

[Risteard]

If I was a tutor I would be more impressed with someone being able to point out that the answers provided were invalid rather than answering what they believed I was looking for.