Arc me up........................

[a1guvner]

Whats peoples thoughts on these pictures, 3P Db, Header trunking above, No leaks above, we believe condensation has built up on the face of the lid and tracked through into the gear tray, see the pic with the covers removed...............

 

[Lucien Nunes]

Ah, didn't see the second set of pics with the rust, that's the problem with reading the forum over a slow mobile phone connection. But the SWA's are deffo in the top of the board, or the cable basket's on the floor open side down!

 

[Darkwood]

Ah, didn't see the second set of pics with the rust, that's the problem with reading the forum over a slow mobile phone connection. But the SWA's are deffo in the top of the board, or the cable basket's on the floor open side down!

I stand corrected not sure why I thought they were in at the bottom ... but the gland termination would be good place to spot that as it would be all corroded too and Im sure the OP would have spotted it when looking for leaks.

 

[lister]

Lightning ?

 

[PEG]

Had a fault like that once, perplexing. Turned out to a split shroud on a SWA supplying an A/C unit outside on the roof, the water was getting in and making it's way down through the armoring and core gaps into the panel, Took some finding luckily I was called back to it when it was raining, worth a look. Good luck.

Difficult to judge,just from pictures,but looks like moisture has been introduced directly to MCB's,possibly through a single conductor. Capillary action is stronger than imagined,and can be assisted if there exists an atmospheric pressure differential,between one end of the conductor and the other,say negative pressure in plant room as a result of ventilation,or a positive pressure + moisture,at its' termination. If you were as sad as i am,this can be checked using an inclined manometer and a pipe the length of the longest circuit...or visually...or just move on with your life,peg...:smilewinkgrin:

 

[nickblake]

had exactly the same happen in a shop water from a leaking bog straight down the center of the board expensive , the rust is a tail tail sign

 

[a1guvner]

I stand corrected not sure why I thought they were in at the bottom ... but the gland termination would be good place to spot that as it would be all corroded too and Im sure the OP would have spotted it when looking for leaks.

Thanks Darkwood, The room does have a bank of 3 boilers which raise the temp quite considerably, the vent does allow air to enter with no filters etc, the fault happened over the xmas break in essex so the boilers were shut down at the time, i am very sure there is no ingress from another source, when we were changing the board there was further evidence of rusting between the board and the paxolin where the slot had been cut.
We have advised the client to get further advice from the ventiltion system designers.

 

[UKMeterman]

Yes it is in a hot plant room, there is some passive ventilation system which i dont really know much about, when we changed the DB we advised the client to check with the installer of the ventilation system, there is a large slatted grill in the plant room wall opposite this DB but about 4 metres away

If it is hot and DAMP in there, check the relative humidity at all times in the plant cycle and shut down. If the plant cycle causes surface condensation then you need kit designed to pollution degree 3, not pollution degree 2.