45amp fuse for shower

[bluespam]

how do you wire a 45amp fuse to a consumer unit when fitting an electric shower?

 

[ZenStalinist]

45 amp fuse... Tell me, do you have an old fashioned 'fusebox' style CU? Or do you mean MCB?

Is the circuit on which the shower is installed already connected to the CU?

 

[ban-all-sheds]

bluespam - your topic originated from the "How To" pages, but instead of the topic "Fitting an electric shower", or "Connecting circuits for shower heater units", you went for "Fitting a Fused Connection Unit (FCU)".

Are you sure you know enough to be doing this?

 

[breezer]

sorry, but from what you have asked makes me nervous, and perhaps you should call in an elctrician, it will be safer

 

[plugwash]

it depends

if you have a modern split load cu with space on the rcd side and a decently rated rcd (80A or more) then you buy a 45A mcb of the right brand clip it to the din rail in the rcd side screw it to the busbar wire the live to the mcb the neutral to the neutral bar for rcd cuircuits (if you aren't sure which is which follow the other wires for breakers on the rcd side)

if you have a modern rcd only cu with a rcd rated at 80A or more and a space then proceed as above

if you have a modern switch only CU with a switch rated at 80A or more then you can use a 45A rcbo (again fo the right brand) theese clip to the rail in the same way as mcbs but have a black wire you conenct to the neutral bar and a cream wire you conenct to the earth bar. live and neutral of the outgoing cable go to the rcbo and earth to the earth bar

if you have a modern split load cu with space on the non-rcd side and a main isolator rated at 80A or more then you can fit a rcbo on the non-rcd side as described above

note that some brnads don't make 45A breakers so you may need to spec your cable for being on a 50A one if 40A is insuffican't for your shower

if your cu does not match any of theese descriptions then you should use a seperate shower unit like this
http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=05435&id=69659

(you can change the mcb to a 40A if suitable)

you will need to henly block it into the tails this is done as follows
fit a double pole henly block to the fuseboard
http://www.screwfix.com/app/sfd/cat/pro.jsp?ts=05950&id=14850

PULL THE SERVICE FUSE
remove the tails from the meter to the existing cu
use fresh 25mm red and black double insulated tails to rewire the cu's

connect meter to henly block
conenct henly block to main cu
connect henly block to shower cu

and put the service fuse back
the main switches in both cus should be off when handleing the service fuse to reduce the risk of arcing

feel free to post a picture of your cu

 

[Big_Spark]

Plug..will you not post pictures of Volex stuff without a warning in big red letters..I nearly fainted from fright

 

[securespark]

Pulling the service fuse best done by REC.........

 

[Juno 60]

Pulling the service fuse best done by REC.........

Well, yeah, but...

I fitted a dedicated shower CU for my 9.5kW using exactly the process described by Plugwash. All hunky dory so far, no trips and no discernible voltage drop when I fire it up.

 

[bungle29]

im looking to put a shawer in but theres no spaces on the main board is there any way i can put a rcd on by wireing from the main board trip switch sorry about the spelling could some one help ????? thanks guys !!!!!!!!!
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[ban-all-sheds]

That's exactly what plugwash describes above.

If you're not looking at that post and thinking "Ah yes, that's all pretty obvious" then you should be thinking "Ah yes, I'd better get an electrician".