7.5kw shower trip

[zedess]

Called to 7.5kw shower on a 30a 1361 fuse in wylex consumer unit,the shower has recently been changed .shower runs for 3-5 mins then pop blows the 30fuse...tested everything...shower circuit etc all readings ok...i know its slightly over its rating as in 7200 on a 7500 shower but i wouldnt expect the fuse to blow on at that level? any ideas. thanx.............or would it

 

[DurhamSparky]

Suggestion!!!

Upgrade the Rewirable to a 32a Push in MCB type!!

32Amp Wylex Plug-in MCB's

extra capacity might be ok!! what soze cable is fitted??? 6mm??

 

[zedess]

yeah its 6mm.. but its a 30a 1361 cartliage fuse in holder in old wylex box...not the old re wirable type.. still dont think a 30a should blow do u ?

 

[oldtimer]

Suggestion!!!

Upgrade the Rewirable to a 32a Push in MCB type!!

32Amp Wylex Plug-in MCB's

extra capacity might be ok!! what soze cable is fitted??? 6mm??

Durham I could be corrected here but an MCB will trip at 1.5 x = 48 amps the rated current a rewireable is 3 x = 90 amps I think the point that it has recently been changed ? has the running current been taken ? slack connections been checked for ? etc

 

[telectrix]

clamp meter it then turn on shower and see if it pulls excessive current after a few mins. the MCB is a good idea as you won't need a pocketful of 1361's

 

[zedess]

yeah checked the lot...it aint the cable..pull switch...all tight and good...would anything in the shower make it blow the fuse? dont think so....wasnt sure on the breaking capacity of the fuse but on yr info its ok.........???

 

[telectrix]

could be the element breaking down when hot, drawing excessive current. i assume it's an old install with no RCD.

 

[zedess]

its an old split load wylex board but with 1361 cartliage fuse in holders, and is on the rcd side of the board...

 

[telectrix]

only way is to measure the current and see if it gets excessive.

 

[SimpleSimon]

Sounds like an overload to me. Tele's got a fairly good theory. Have a visual check of the elements see if there's anything apparent.

 

[malcolmsanford]

its an old split load wylex board but with 1361 cartliage fuse in holders, and is on the rcd side of the board...

Is this a modified CU as I can't ever remember a Wylex 1361 board having RCD capabilities, as it would need at least 2 neutral

 

[DurhamSparky]

i have seen them CU!!! you can drop a mcb on the din rail behind!! its one of the version of "New" Wylex Cu's before 60898 mcb became the rage!

 

[zedess]

thanx guys .will do

 

[zedess]

so.i could a 32a 60898 mcb onto this c/u ..thanx for that.

 

[Chr!s]

Drawing around 70 amps for 5 min disconnection, IR L - N ok?, Have you tested the rcd?