Shower switch problem

Hi guys

I've had an issue when coming to installing a shower circuit. I have feed a 10 mm cable from a 45mcb to a double pole 45a isolator switch. I've then taken another 10mm cable from the isolator switch to the shower. Right, so my connections have been done.

So I made the connections as explained.

As the customer did not have a shower fitted in, no connections Were made

A couple of weeks later the customer has A plumber fit the shower, he also made the connections, which were quiet simple.

The problem now is when the isolator switch is on, the electric showers light comes on when the shower is in the off position.

so I turned the power switch on the electric shower (as this is also the temperature switch too) and what happen was it acted like a switch turning the double pole isolator off and on. This also made the RCD trip but still gave power to the MCB...

The shower circuit is on its own MCB...

Now I am completely confused to what has gone wrong on something so straight forward. I've done a continuity test on the connection from the shower to the dp switch, when I turn the shower switch on from the temperature gauge, the wires in the dp switch Become live, the shower is basically acting like a switch turning the neon light in the dp switch off an on.

Any help will be great. I'm kicking myself to what has happen. I personally can only point the fault to the shower, the customer said the shower was brought this February

 

I wired it into the consumer unit myself, but what is baffling me is why the shower switches the dp switch on and off. I added a new mcb and made my connections from the mcb to the dp switch, then another wire from dp too the shower

 

Yes I have checked the plumbers connections, what he had done was mess about with my connections at the do switch. Initially the power light on the shower was flickering. So I thought it would be a loose neutral, which it was. Once I put the neutral back in the shower light was on in the off position.

This is when I turned the power gauge once and it tripped, so I turned again and it then started to affect the neon light on the do switch.

 

whats worrying at the moment is why the dp pull cord switch is not cutting off the power. If I cut off the power then turn the gauge on from the shower, it activates the dp switch...

 

Hi

What I'm saying is when the shower is actually turned on, the light on the dp switch turns off.

When I pull the cord in the dp switch the electric showers light is on (even through the electric shower is in the off position) when I turn the gauge on the electric shower it on it trips the RCD. The MCB still has power so when I turn it another notch the neon in the dp switch goes off, when I turn it the other way the dp switch goes on...

 

Hi

I get what your saying, I've isolated the power and turned off the mcb. I've done these connections before, but what is baffling me is why this is happening. Why is the ShOwer gauge making the DP switch live.

From my experience I think it's the shower that is faulty as it's sending a live current to the dp switch, which means the connection is not doing its job correctly. I've heard that a part in the shower can cause problems.

If I don't try these things in a "safe" manner, I will never know how to approach the problem... with hunch is why I was hoping for a little guidance

 

This only has one RCD, it's not an RCBO

 

Sorry there is no problem with the dp switch, I already brought. New one to cover that scenario, I also double checked the connections with the load and supply, they are both correct. Also the earth has been connected to a separate terminal, I did no attach it to the dp switch as it was slightly problematic

 

I have put the MCB on the other side of the RCD... But I thought this would be sufficient enough.

 

Hi that is exactly what I have done... what had happened was before I had connections switched the wrong way which was causeing a trip, I then changed the neutral onto the other bar, thinking back I did forget to change the neutral back to the original bar...

So the issue really lies with the neutral being on the opposite side....

I can't see the wires on the dp switch, but I will try earthing the switch itself, hopefully this resolves the problem.

The only thing confusing now is why is the power light indicated on the shower constantly on... I thought once the temp gauge has been rotated once (as the temp gage has three heat settings) it would power up and the light would come on to indicate it's powered...