can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW shower

[Sintra]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

Mate you can't put the cables on separate MCB's end off. You need to read the part in bs7671 regarding conductors in parallel.

 

[mikejd]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

But the (40A) current is shared down two 6mm cables (approx 20A down each). And each 6mm cable has its own 30A mcb back in the CU. From the 50A isolator pull switch near shower, where they join, the single cable to the shower is then 10mm. I cant see any over loading / overheating at all. Am I still missing something here.

Except for failure to comply with regulations why would this not be safe?
Any advice really appreciated
Thanks

 

[gazj82]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

perfectly OK till the insulation monkeys smother the cable.

I agree, but should we have to comply with every idiot that might come along and do something like this. The insulation monkeys should be educated, before stuffing the loft full of the stuff!

EDIT: Just read this again, I don't think you was implying we should

 

[jackhammerJIM]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

2 separate supplies joined together .

your having a laugh mate .

DIY FORUM

 

[Sintra]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

But the (40A) current is shared down two 6mm cables (approx 20A down each). And each 6mm cable has its own 30A mcb back in the CU. From the 50A isolator pull switch near shower, where they join, the single cable to the shower is then 10mm. I cant see any over loading / overheating at all. Am I still missing something here.

Except for failure to comply with regulations why would this not be safe?
Any advice really appreciated
Thanks

If you think a 30A mcb will trip out at 30A you are mistaken.

 

[Octopus]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

But the (40A) current is shared down two 6mm cables (approx 20A down each). And each 6mm cable has its own 30A mcb back in the CU. From the 50A isolator pull switch near shower, where they join, the single cable to the shower is then 10mm. I cant see any over loading / overheating at all. Am I still missing something here.

Except for failure to comply with regulations why would this not be safe?
Any advice really appreciated
Thanks

What training/competence/test kit do you have?

 

[Sintra]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

Op can I ask your qualifications please as this is basic stuff.

 

[Plonker 3]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

I just think we need to leave this thread alone, no matter what we tell the OP it just seems to fall on deaf ears.

I want to know who is going to get here first Glenn or Biff.

 

[Octopus]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

This thread is the classic example of how Dan needs to change the forum. If the OP is unwilling to attempt to answer some of the questions he should be put on a ban until he does.

 

[Specialist]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

According to his profile he's a teacher, hope he knows a bloody sight more about that than he does about electrics .

 

[hasel5]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

Oh dear oh dear what a mess

 

[Wiresandthings]

Just do yourself a favour mate and call and electrician! What your planning on embarking on is just plain stupid! Plenty of safe solutions to this problem!

 

[Alex Ramage]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

But the (40A) current is shared down two 6mm cables (approx 20A down each). And each 6mm cable has its own 30A mcb back in the CU. From the 50A isolator pull switch near shower, where they join, the single cable to the shower is then 10mm. I cant see any over loading / overheating at all. Am I still missing something here.

Except for failure to comply with regulations why would this not be safe?
Any advice really appreciated
Thanks

OK buddy. Jokes over. You've had your fun now toddle off to some other trades website and wind them up

 

[jimjimjim]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

My god, i didn't realise until half way through he was talking about two seperate breakers bahahahahah. This has to be a wind up.

Jim

 

[Guest55]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

theres only 1 poster i can think of that covers this........

 

[Octopus]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

Fingers crossed he's not a science/Physics teacher!

 

[MUFC1999]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

This thread is the classic example of how Dan needs to change the forum. If the OP is unwilling to attempt to answer some of the questions he should be put on a ban until he does.

Unfortunately this will not stop him doing what he thinks is OK.

Any basic understanding of the regs tells you this can't be done.

 

[mikejd]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

Thanks to you who have replied genuinely to my question, without feeling the need to result to sarcasm. No I am not a qualified electrician and never claimed to be but I am both a physics graduate and electronics engineer. I never doubted that regs would not allow this to be done, though from an electrical theory perspective it is perfectly feasible, Its a shame very few replies seemed to go beyond 'you cant do it as it breaks the regs' and considered the theoretical reasons why...of which there are few.
Thanks again

 

[amlu]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

replace individual mcb for each cable for 1x mcb for both cables. 32a should do the job. connect both cables to it, then join them at other end and attach to a length of 10mm going into the shower.

 

[Deleted member 9648]

Re: can two 6mm csa cables each with 30A mcb in joined at 50A dps to supply 9.5kW sh

Thanks to you who have replied genuinely to my question, without feeling the need to result to sarcasm. No I am not a qualified electrician and never claimed to be but I am both a physics graduate and electronics engineer. I never doubted that regs would not allow this to be done, though from an electrical theory perspective it is perfectly feasible, Its a shame very few replies seemed to go beyond 'you cant do it as it breaks the regs' and considered the theoretical reasons why...of which there are few.
Thanks again

The main reason being that supplying a circuit with two separate MCB's creates problems with isolation. Another reason is that two MCB's in parallel are an unknown quantity for short circuit and overload protection. You cant do it. End of.