shower tripping rcbo?

[Apache]

Naughty boy. I don`t care if "you don`t have test gear for personal use" - if that is the case you can`t do "personal works" can you??

If you want to moonlight -buy the necessary equipment :red card

You can pick up some second hand separates on ebay for ~

 

[SPECIAL LOCATION]

Sorry kme. You know what I meant tho lol. Retiring to pit now

While your down t'pit lad shovel a couple o buckets of coal for us to shove on the fire....

Bl00dy gas and lectrik gewn up gonna have to dig me own coal soon!!!!

 

[kme]

Remember, tho - shift is 25 hrs a day; AND pay t`mill owner for permission to go to work!

 

[SLIPSHOD & SLAPDASH]

Hi As the shower is a fixed Load then it is exempt from the need for overload protection. If the cable meets the requirements for the fixed load then no problem with a 40 Amp RCBO.

See BRB under Overcurrent - exemptions for requirements of Overload protection

I can't believe no one has picked up on this !

This comment is so very wrong and misleading to use it in the context. I am gobsmacked an Niceic approved contractor thinks this.

The regs do not say this about final circuits.

Also, unless this shower has been fitted in the lounge when can you say a bathroom is not a special location ? What about the protection to the 15m of cable ? In fact please tell me where you think its written no overload protection is needed ?

EDIT overload or overcurrent

 

[sparkytim]

I can't believe no one has picked up on this !This comment is so very wrong and misleading to use it in the context. I am gobsmacked an Niceic approved contractor thinks this.

The regs do not say this about final circuits.

Also, unless this shower has been fitted in the lounge when can you say a bathroom is not a special location ? What about the protection to the 15m of cable ? In fact please tell me where you think its written no overload protection is needed ?

EDIT overload or overcurrent

BRB Pg 74 433.3.1 (ii)

see also NIC Tech Manual section O 069-1 3.2

".......example of this is a SHOWER circuit...."

We are not talking of FAULT current here, Just OVERLOAD.

The 15 Mtrs of cable CAN-NOT be OVERLOADED as the load is fixed.

 

[SLIPSHOD & SLAPDASH]

Your wrong. Are you telling me its acceptable to fit only a Rcd to a final circuit with no CPD except the main fuse, which most likely will be 100A ?

As i posted earlier, The regs in section 433.3 ARE NOT to be used in a special location, which a bathroom is. Also tell me how (re 433.3.2.1), a 60 or 100 Amp main fuse is effectively protecting a 8.5kw shower circuit against overload. As an example, damp getting into a joint or damaged area of cable between L & N which lowers the insulation resistance ?

In note 3 of the introduction to section 43 it states the protection of conductors according to these regulations does not necessarily protect the equipment . All shower manufacturers state the shower must be protected by a fuse or circuit breaker (Values change depending on loadings) I cant remember the reg that states you have to follow manufacturers instructions (anyone ?)

I do not have any Niceic publications so can not comment on their view of this, but it should be no different to the regs, just examples.

 

[Andy™]

Your wrong. Are you telling me its acceptable to fit only a Rcd to a final circuit with no CPD except the main fuse, which most likely will be 100A ?

he didnt say only RCD. he said 40A RCBO.

the shower cannot overload, so overload protection is not needed. but fault protection is. hence the 40A RCBO part. the 40A will protect the cable fomr fault current

---------- AUTO MERGE Post added at 18:39 ---------- Previous post was at 18:34 ----------

I can't believe no one has picked up on this !because there is nothing wrong with itThis comment is so very wrong and misleading to use it in the context. I am gobsmacked an Niceic approved contractor thinks this.why? like i said, there is nothing wrong with it

The regs do not say this about final circuits. they do. go read 433.3.1

Also, unless this shower has been fitted in the lounge when can you say a bathroom is not a special location ?whats that got to do with anything? What about the protection to the 15m of cable ? as long as its protected against fault current, t doesnt need protection against overload since that cannot happenIn fact please tell me where you think its written no overload protection is needed ? 433.3.1(ii).

EDIT overload or overcurrent

my red

 

[sparkytim]

Your wrong. Are you telling me its acceptable to fit only a Rcd to a final circuit with no CPD except the main fuse, which most likely will be 100A ?As i posted earlier, The regs in section 433.3 ARE NOT to be used in a special location, which a bathroom is. Also tell me how (re 433.3.2.1), a 60 or 100 Amp main fuse is effectively protecting a 8.5kw shower circuit against overload. As an example, damp getting into a joint or damaged area of cable between L & N which lowers the insulation resistance ?

In note 3 of the introduction to section 43 it states the protection of conductors according to these regulations does not necessarily protect the equipment . All shower manufacturers state the shower must be protected by a fuse or circuit breaker (Values change depending on loadings) I cant remember the reg that states you have to follow manufacturers instructions (anyone ?)

I do not have any Niceic publications so can not comment on their view of this, but it should be no different to the regs, just examples.

NO, Thats not what It means,

The cable has to be protected against Over-current, this of course means a CPD in addition to the RCD, a Fuse or MCB. A RCBO already includes that protection.

However that OVERCURRENT would be due to a FAULT condition in the form of a SHORT CIRCUIT, the RCD protects against faults to earth.

In determining what size MCB is required to protect the cable to a FIXED load then OVERLOAD is not an issue the same as it is with a circuit serving Sockets that could be overloaded.

Hence a 6mm cable to a shower drawing 36 Amps could be protected by a 40 A MCB even if the max the 6mm should be ALLOWED to carry is 36 Amps.

---------- AUTO MERGE Post added at 18:56 ---------- Previous post was at 18:50 ----------

All NICEIC contractors have access to the TECH MANUAL, now also called the ESSENTIAL GUIDE accessible on the NICEIC Website.

 

[SLIPSHOD & SLAPDASH]

Thanks Andy for pointing out my error in missing the RCBO !, How did i miss that headbang i don't know why Tim did not mention this as everything else is immaterial. I think i also did not put it to well that although i quite understand about the cable overload protection, that is immaterial as you still have to have the fault protection. Thanks Tim for reminding me about the tech manual. I think i will now :coat

 

[safedepth]

Hi,Didn't say there was a problem, just the fact that a 40A Type B RCBO will happily carry 50A all day without tripping, and 6mm cable is rated at 47A at the very best, makes me err on the side of caution.

A 32A breaker would be more than enough for an 8500w load, just me I guess

---------- AUTO MERGE Post added at 23:00 ---------- Previous post was at 22:57 ----------

Definately, especially with water about, but you need to do some tests first.

R1 + R2, IR, ZS etc.

But surely as the 40a breaker will carry 50a, the 6mm cable will cope with the extra current without bursting in to flames. It is rated at 46a (ref Method C) but that does allow for the short term overload situation. We install to the regs as somebody has done the calcs for us. We don't limit 6mm cable to 46 amps because at 47 it melts.

I agree a 32a will take the load, it is strictly speaking going to stress the breaker. At 220v the load would be approaching 39a.

 

[kme]

But surely as the 40a breaker will carry 50a, the 6mm cable will cope with the extra current without bursting in to flames. It is rated at 46a (ref Method C) but that does allow for the short term overload situation. We install to the regs as somebody has done the calcs for us. We don't limit 6mm cable to 46 amps because at 47 it melts.I agree a 32a will take the load, it is strictly speaking going to stress the breaker. At 220v the load would be approaching 39a.

Reg 433.1 (initial comment), & 433.1.1 in its entirety refer.

 

[safedepth]

Reg 433.1 (initial comment), & 433.1.1 in its entirety refer.

KME,

I'm not sure what , (if anything) you are trying to educate me on so please don't bite my head off.

433.1 Hence use the 40a breaker.

433.1.1(ii) No problem so long as the installation method is conducive to the choices made.

(iii) could be an issue.

 

[SLIPSHOD & SLAPDASH]

Whazza2, have you found the problem from the o/p yet ?

 

[kme]

I wasn`t trying to educate you mate, just pointing to what I considered to be a pertinent reg.

:coat

 

[safedepth]

I wasn`t trying to educate you mate, just pointing to what I considered to be a pertinent reg. :coat

Thanks mate. For a while I felt like I was back in the classroom with the cone shaped hat on being asked why I was talking to the boy next to me!!!