outdoor cable woes

[momo32]

Just reread your first post (always wise!) and note that you had the area (over?) the cable paved. Sounds like you need to have the cable tested Have had similar experience recently.

 

[Invisible-Man]

So is it at all possible that it's actually the shower at fault??

its not the shower as that doesnt trip the rcd....if i switch the mcb on to the garage the rcd will trip

At least we seem to have found out that if there is an earth fault, it must be on the live side as if on the neutral side the switching off of the mcb would not stop the rcd from tripping

Have I got a point ?

 

[breezer]

its not the shower as that doesnt trip the rcd....if i switch the mcb on to the garage the rcd will trip

wish you had said that in the first place.

it proves its not the cable.

since the cable is always connected, it has to be as i said something else, leave it for today, but did you take the lamps out, and what sort of fittong are they?

I am thinking they may be bulkheads filling with water (AKA flood lights)

 

[momo32]

its not the shower as that doesnt trip the rcd....if i switch the mcb on to the garage the rcd will trip

wish you had said that in the first place.

it proves its not the cable.

since the cable is always connected, it has to be as i said something else, leave it for today, but did you take the lamps out, and what sort of fittong are they?

I am thinking they may be bulkheads filling with water (AKA flood lights)

But: he's turned off the CU in the garage (we assume DP switch?). The house RCD only trips when he turns ON the garage MCB in the house. The fault has to be (a) between phase and earth and (b) between the MCB and the supply side of the garage CU. That leaves the cable, surely? or am I being simplistic

 

[Invisible-Man]

its not the shower as that doesnt trip the rcd....if i switch the mcb on to the garage the rcd will trip

wish you had said that in the first place.

it proves its not the cable.

since the cable is always connected, it has to be as i said something else, leave it for today, but did you take the lamps out, and what sort of fittong are they?

I am thinking they may be bulkheads filling with water (AKA flood lights)

The live is not always connected!

 

[breezer]

but the cable is still conected though. (at the house end)

despite what is on or off the earth is connected, so if either core has "gone down" it would make no difference if the garage cu is on or off

its probaly feeding back through something, which is why i said remove all plugs and the lamps.

I wonder how the heaters are connected?

if they are plugged in unplug them too

 

[momo32]

but the cable is still conected though. (at the house end)

despite what is on or off the earth is connected, so if either core has "gone down" it would make no difference if the garage cu is on or off

its probaly feeding back through something, which is why i said remove all plugs and the lamps.

I wonder how the heaters are connected?

if they are plugged in unplug them too

Don't get that... Do you not use a DP isolator for just that purpose - isolation? I agree the CPC is always connected but the phase and neutral aren't if the DP switch is off so how can 'it feed back' anywhere??

 

[Invisible-Man]

but the cable is still conected though. (at the house end)

despite what is on or off the earth is connected, so if either core has "gone down" it would make no difference if the garage cu is on or off

its probaly feeding back through something, which is why i said remove all plugs and the lamps.

I wonder how the heaters are connected?

if they are plugged in unplug them too

But the phase is not connected at the house end when the mcb is off, surely if there was phase to earth break in the cable, this would give the scenareo of only tripping the rcd when the mcb in the house is in the on position! I think I'm with momo32 on this one

 

[breezer]

gentlemen (two replies)

read my post again

it probable back feeds when the garage cu is turned on

the swa will be connected on both cores if the mcb is on, the op never said he turned it off.

the op did say the hose rcd trips ehn he turns on the garage cu.

most people (i leant out of the window and asked) said they would leave the house mcb on since there is no need to turn it off.

which there fore means both cores of the swa are connected

 

[Invisible-Man]

gentlemen (two replies)

read my post again

it probable back feeds when the garage cu is turned on

the swa will be connected on both cores if the mcb is on, the op never said he turned it off.

the op did say the hose rcd trips ehn he turns on the garage cu.

most people (i leant out of the window and asked) said they would leave the house mcb on since there is no need to turn it off.

which there fore means both cores of the swa are connected

But he did say he turned it off, he has to turn the mcb off in the house which supplies the garage in order to be able to take a shower in the house, as this is the only way he can stop the house rcd from tripping

(he said, if I switch on the mcb to the garage, not in the garage!)

 

[breezer]

my eyes must be going, i dont diss believe you, where did he say that?

 

[tritonr1]

ok guys heres what i did....switched the mcb off in the house to the garage....went into the garage and disconected the swa from the cu in the garage, kept the wires seperated with block connector ....went back to the house to switch on the mcb and the rcd still tripped out

 

[breezer]

regretfully that is the cable, but what were they using to lay the block paving with? a jcb?

a swa cable is designed to take a lot of punishment (JCB's NOT included)

 

[tritonr1]

jcb was used when the digging out was done...the only thing i can think is that they nicked the cable and over time water has gotten in ....anyway would it be safe to replace the cable with 2.5 or would you reccommend 4mm

 

[Invisible-Man]

So is it at all possible that it's actually the shower at fault??

its not the shower as that doesnt trip the rcd....if i switch the mcb on to the garage the rcd will trip

For Breezer, as requested above

PS was not questioning your expertise and had already come to the conclusion that you mis-read where the mcb was sited!

Obviously damage on the phase side of the cable