Was this standard practise???

[Carlos Arruda]

Was this standard practice back then? (1979).

A 30A rewirable fuse for two ring mains?

https://www.dropbox.com/s/ckb0ikxntr5prkv/20150418_104206.jpg?dl=0https://www.dropbox.com/s/ckb0ikxntr5prkv/20150418_104206.jpg?dl=0

 

[telectrix]

Matey. Don't install dual boards. Install Hi-integrity.

AND I don't agree with somebody else testing and signing off your work, Its NOT the way to set out!

but if his tutor is supervising the whole job, why not? carlos could sign for the install, and the tutor sign as QS.

 

[Octopus]

but if his tutor is supervising the whole job, why not? carlos could sign for the install, and the tutor sign as QS.

IF the supervisor is involved so much WHY is he on here asking so many questions?

 

[telectrix]

from his previous posts, it seems just a general thirst for knowledge. tutors can sometimes be wrong and a second opinion or 6 is worth having. unlike tutors, the forum is on call 24/7. lol.

 

[Leesparkykent]

Don't scare the lad off. As long as he's under supervision by his tutor I don't see no problem.

 

[Carlos Arruda]

from his previous posts, it seems just a general thirst for knowledge. tutors can sometimes be wrong and a second opinion or 6 is worth having. unlike tutors, the forum is on call 24/7. lol.

Telectricx,

You are bang on the money.

Many thanks.

I have asked the admin for access to the trainee forum as recommended.

Regards,
Albert

 

[Guest77]

Don't scare the lad off. As long as he's under supervision by his tutor I don't see no problem.

I have no intentions of scaring the Lad off, the tutor however= well that is different.

 

[Octopus]

Don't scare the lad off. As long as he's under supervision by his tutor I don't see no problem.

BUT posting step by step instructions in the open forum is not the thing to do as any Tom, Dick or Harry could act on it.

 

[Carlos Arruda]

BUT posting step by step instructions in the open forum is not the thing to do as any Tom, Dick or Harry could act on it.

Hi Murdoch.

I utterly see where you come from.

When it comes to electricity there should be no cutting corners.

But then again, in one of my tasks, the calculated CSA of a cable for an immersion heater came at 16mm.

Still, this is not what it is used on a normal basis or so it seems.

I am a bit annoyed (have been for quite sometime now) with the regs, giving calculations to determine a cable size, given the length and factors like Cc, Ca, Cd, Cf, Ci, Cg & Cs, and then this can be overlooked, provided that the size of the CPC supports any fault (PFC) to earth to the total current calculated with the adiabatic equation. Sort of one contradicts the other.

Still, all the help/advise I can get is priceless.

Many thanks to yourself and all others chipping in.

Regards,
Albert

 

[Carlos Arruda]

Matey. Don't install dual boards. Install Hi-integrity.

AND I don't agree with somebody else testing and signing off your work, Its NOT the way to set out!

Murdoch;

Apologies for the ignorance but what is the difference between split load C.Us and Hi-Integraty C.Us?

I have just been to screwfix online and a Hi-Integrity C.U. has two RCDs and also seems to be a split load C.U.

I must be missing something.

Sorry, but I believe there hasn't ever been any talk about Hi-Integrity C.U.s, unless off-course, I was on my face sleeping.

Many thanks.

Regards,
Albert

 

[telectrix]

Murdoch;

Apologies for the ignorance but what is the difference between split load C.Us and Hi-Integraty C.Us?

I have just been to screwfix online and a Hi-Integrity C.U. has two RCDs and also seems to be a split load C.U.

I must be missing something.

Sorry, but I believe there hasn't ever been any talk about Hi-Integrity C.U.s, unless off-course, I was on my face sleeping.

Many thanks.

Regards,
Albert

a hi-integrity board is just like a dual RCD board except that there is also the option of having 1 or more ways directly off the main switch and not through the RCDs. these ways can be used for a circuit that for some reason, you don'tr want or need a RCD, or they can each have a RCBO. eg. for a freezer, so that a fault on another circuit does not take out the freezer circuit.

 

[Carlos Arruda]

Murdoch made a good point, who says it's 2 ring final circuits, have you carried out the tests required to verify if they are Rings? https://www.youtube.com/watch?v=uPKksOxQTPI

Hi Pete999.

I have removed all cables out leaving only one and powering only this circuit.

Upon using my volt tester, I found voltage in one of the unplugged 3 cables. Other 2 were still dead.

Done the same on the 2 dead ones to find voltage was also going round and back in.

For me, without any other form of testing at the time, is good enough to let me know these 4 cables are two ring mains.

On top of that, I also used the two pairs for each circuit, and confirmed that one circuit is downstairs and the other is upstairs.

There was no voltage in any of the 4 cables when unplugged.

Many thanks for all the help.

Regards,
Albert

 

[Carlos Arruda]

a hi-integrity board is just like a dual RCD board except that there is also the option of having 1 or more ways directly off the main switch and not through the RCDs. these ways can be used for a circuit that for some reason, you don'tr want or need a RCD, or they can each have a RCBO. eg. for a freezer, so that a fault on another circuit does not take out the freezer circuit.

Thanks.

I thought I could still do this even on a split load C.U.

I did wonder if I could just use a separate MCB for the garage and have this not RCD protected, and have the RCD in the garage unit.

But as it stands, it seems all circuits need/must be RCD protected. Or at least in this case.

Many thanks.

Regards,
Albert

P.S: I might go down the root to have a separate RCBO to serve the garage, therefore the circuit supplying the garage would comply with the regs.

 

[telectrix]

Hi Pete999.

I have removed all cables out leaving only one and powering only this circuit.

Upon using my volt tester, I found voltage in one of the unplugged 3 cables. Other 2 were still dead.

Done the same on the 2 dead ones to find voltage was also going round and back in.

For me, without any other form of testing at the time, is good enough to let me know these 4 cables are two ring mains.

On top of that, I also used the two pairs for each circuit, and confirmed that one circuit is downstairs and the other is upstairs.

There was no voltage in any of the 4 cables when unplugged.

Many thanks for all the help.

Regards,
Albert

that was completely the wrong way to test. never work live if you can work with circuit/s isolated. in this case, you should have done continuity and maybe IR tests to see if the circuits had continuity end-end, and if they were cross connected one to another.

 

[Carlos Arruda]

I must say I am slight worried about the garage as there's an ARC welding machine.

It seems it pulls 180A on start according to the owner. I am wondering if a 32A MCB type C will handle this. One of my tutors said I might have to bump it up to a type D even, but it might the case of trial and error here. Use the type C and see how it copes and then replace it if need be.

He says he's never had any issues as the installation is and I am thinking he's on a 2.5mm CSA at the momen on a rewirable 30A fuse serving two other circuits.

 

[Carlos Arruda]

that was completely the wrong way to test. never work live if you can work with circuit/s isolated. in this case, you should have done continuity and maybe IR tests to see if the circuits had continuity end-end, and if they were cross connected one to another.

I do understand about the live tests and one cannot be to carefully.

I did do the continuity with my volt tester which also does continuity.

This is it.

I am not entirely sure about the 30A fuse number 5 with 3 cables. I know one is serving the fluorescent light at the rear and the other two look like spurs, as when powered, I had power on sockets on the hallway (fax and towel heater in bathroom) and the other one is powering a small conservatory.

Having said that, circuit dead, these two cables out and tested between them for continuity, they do have continuity, so I am wondering spurs? But if on a ring main, why one cable is powering hall sockets and other feeds conservatory? I did wonder if there was a break on this ring, cannot know with the proper gear, but again, testing for continuity with my volt tester, they pass.

???:whatchutalkingabout