I had a new CU installed four years ago in an outside utility room,original fuse boxes were inside kitchen.The installers ran in new cables and connected to exisitng wiring using connection boxes which were pushed up into wall and plastered over using plaster board.
When there is bad weather, combination of rain/wind the main CU isolator comes out and will not reset.By isolating all the upstairs sockets by taking out the relevant MCB the isolator stays on ,so the problem is somewhere on that circuit.After a few hours or days depending on the outside climate all returns to normal.This would point to water getting in somewhere-I have checked all sockets in circuit concerned ,all dry.
Have discovered today a leak on the outside wall(solid rendered)behind a downpipe which is now fixed,and this has allowed water to track through the morter down the wall where the new cables to the junction boxes have been run.The JB!s located in the wall are a further metre along the wall from where the morter is damp.
My question is would damp air trapped behind the plaster board be sufficient to allow earth leakage and trip the RCD or does there have to be actual water ingress into a JB
Dont want to get into JB!s unless I have to as a lot of work involved.
Any ideas appreciated ie how does one go about isolating where fault is on circuit
When there is bad weather, combination of rain/wind the main CU isolator comes out and will not reset.By isolating all the upstairs sockets by taking out the relevant MCB the isolator stays on ,so the problem is somewhere on that circuit.After a few hours or days depending on the outside climate all returns to normal.This would point to water getting in somewhere-I have checked all sockets in circuit concerned ,all dry.
Have discovered today a leak on the outside wall(solid rendered)behind a downpipe which is now fixed,and this has allowed water to track through the morter down the wall where the new cables to the junction boxes have been run.The JB!s located in the wall are a further metre along the wall from where the morter is damp.
My question is would damp air trapped behind the plaster board be sufficient to allow earth leakage and trip the RCD or does there have to be actual water ingress into a JB
Dont want to get into JB!s unless I have to as a lot of work involved.
Any ideas appreciated ie how does one go about isolating where fault is on circuit