Shower Problems - Can Anybody Help?

[Rosko1987]

Hey everyone, how you doing?

Iv a problem with the new shower in our house....

Its a 9.5KW Trition Ivory 4 shower, Supplied with a 10mm twin & earth cable via a 50Amp breaker.

The length of the cable run is about 20meters from the board, under the floorboards, up the cavity to the loft and then down the wall into the shower.

We've previously never had any trouble with the old shower but decided to change it when renovating the bathroom. The cable itself is in fine condition and the connections are all sound.

We usually only get about 5mins before the breaker trips and so turns the shower off. The water supply is ok, but not great.

Can anyone offer any help or advice please?

much appreciated

 

[Octopus]

Get an electrician to check out the circuit or get a plumber to check the water pressure?

 

[Rosko1987]

Yeah, Im an electrician and iv checked the cable and connections. Im thinking though the water pressure might not be good enough? im also wondering whether a 50amp breaker is excessive?

 

[Octopus]

Yeah, Im an electrician and iv checked the cable and connections. Im thinking though the water pressure might not be good enough? im also wondering whether a 50amp breaker is excessive?

what are the readings of your tests?

Lowering the breaker to 45A or 40A will probably make it trip quicker.

 

[steveberry11]

How have you checked the cable?
The water pressure would not cause the MCB to trip as the shower should have an internal over temp device to cut the supply.
i guess you have checked the shower?

 

[sparky-s-w]

would have thought a 45amp would usualy be sufficient, but a smaller breaker will only trip sooner. sounds like there is a problem with either she shower itself, connections, water pressure, or less likley a faulty breaker. is it on an RCBO or MCB?, is there an RCD in place?

 

[wallyanker]

Yeah, Im an electrician and iv checked the cable and connections. Im thinking though the water pressure might not be good enough? im also wondering whether a 50amp breaker is excessive?

The breaker is there to protect the cable, so 50a is fine on 10mm cable. If all your tests come back ok, sounds like a faulty element in the shower.

 

[Rosko1987]

No readings as such. I only checked the cable to make sure there was no burns or bad connections. I did however check between L+E, L+N, N+E and the cable appeared to be clear

 

[steveberry11]

Did you carry out any insulation resistance tests?
The breaker that trips is this an RCD or a RCD?

 

[Richard Burns]

If the 50A breaker trips in about five minutes then it should be taking about 90A, worth clamping the cable to see if it is pulling this on start up, if so then the shower is likely faulty and should be returned for a replacement.
If the current is not at this level then either the fault occurs after five minutes, which seems unlikely or the breaker is faulty, for the cost of a breaker it may then be worth changing.
What was your Zs reading or R1+R2 reading as this would tell you if there was a wiring problem before the shower.
I am assuming your "

L+E, L+N, N+E and the cable appeared to be clear" indicates that you performed an insulation resistance test and the readings came out greater than, say 200 Mohms.

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Did you change anything else apart from the shower, e.g. the isolation switch, etc.?

 

[Rosko1987]

Interesting. Iv no clamp meter and was using one of the guys i work with tester. The breaker in question is just a simple breaker thats part of the old doorman smith board so theres every chance it is faulty

 

[sparky-s-w]

for the cost i suppose you could change the breaker, however i would be more inclind to think the fault is shower end, as the problem started after the shower was changed.

 

[telectrix]

for the cost involved, i would first replace the MCB, then a clamp meter to see what the shower is actually pulling. if it's over 40A then i would suspect the shower unit itself.