shower

[ericmark]

If you are going to change the MCB fit exactly the size already fitted. If an electrician after looking at the job says a larger one can be fitted OK but you don't have the skills judge what the cable can take.

Really not safe for you to change MCB.

 

[EFLImpudence]

If you are going to change the MCB fit exactly the size already fitted.

What would be the point of that?

If an electrician after looking at the job says a larger one can be fitted OK but you don't have the skills judge what the cable can take.

No skill is required, other than the knowledge that it is satisfactory (hence the OSG), to install 6mm² cable, keep it away from thermal insulation and out of conduit, and connect it to a 40A OPD.

OP may not have electrical skills but I have emphasised the fact that the cable must run through no thermal insulation nor conduit.
I do not think it will take much skill to determine that.

If that is determined then the 6mm² cable will be rated at 47A and be well protected by a 40A fuse/mcb and capable of safely conducting the 39.6A current drawn by the shower.

Really not safe for you to change MCB.

See above.


Bamboozling DIYers with time/current curves and 10,000 seconds references is of no help at all.
Thermosetting cable is rated higher so what is the point of mentioning that?

If what you mean is that the OP should 'just leave alone and get an electrician' then why not just say that?


Information, as said above -

9.5kW @ 240V = 39.6A This is what will be stated by the manufacturer.
This is equivalent to 8.74kW @ 230V = 38A

8.5kW @ 240V = 35.4A This is what will be stated by the manufacturer.
This is equivalent to 7.8kW @ 230V = 33.9A

So, all under 40A - so no overheating of 40A MCB
and all over 30A - so present device would still overheat and trip.

 

[karlywarly1969]

If you are going to change the MCB fit exactly the size already fitted.

What would be the point of that?

If an electrician after looking at the job says a larger one can be fitted OK but you don't have the skills judge what the cable can take.

No skill is required, other than the knowledge that it is satisfactory (hence the OSG), to install 6mm² cable, keep it away from thermal insulation and out of conduit, and connect it to a 40A OPD.

OP may not have electrical skills but I have emphasised the fact that the cable must run through no thermal insulation nor conduit.
I do not think it will take much skill to determine that.

If that is determined then the 6mm² cable will be rated at 47A and be well protected by a 40A fuse/mcb and capable of safely conducting the 39.6A current drawn by the shower.

Really not safe for you to change MCB.

See above.


Bamboozling DIYers with time/current curves and 10,000 seconds references is of no help at all.
Thermosetting cable is rated higher so what is the point of mentioning that?

If what you mean is that the OP should 'just leave alone and get an electrician' then why not just say that?


Information, as said above -

9.5kW @ 240V = 39.6A This is what will be stated by the manufacturer.
This is equivalent to 8.74kW @ 230V = 38A

8.5kW @ 240V = 35.4A This is what will be stated by the manufacturer.
This is equivalent to 7.8kW @ 230V = 33.9A

So, all under 40A - so no overheating of 40A MCB
and all over 30A - so present device would still trip.

So what do I need to do....take out the 9.5kw or can I leave it in.......or do I buy an 8.5kw?

 

[EFLImpudence]

If the cable is safe regarding the 'no insulation and conduit' then just have a 40A fuse/mcb fitted.

Could you ask the original electrician why he fitted a 30A?
Or - did you just have a plumber fit a bigger shower?

Did it ever work without tripping?