Cable Tray Fires

[eg6791]

Recently, we have had seperate instances of cable tray fires due to boiler washdowns. Alot of our cable trays that were installed when the plant was built are not enclosed and do not have covers on them. Due to some of the locations of these cable trays, alot of the cables and their insulation over the years have become very brittle, some even cracking due to the ambient temperatures around the boilers on the upper floors allowing for faults to occur when the water hits the bad cables. Has anyone in the power gen industry specifically had any issues with cable tray fires due to washdowns or other similar events dealing with water/liquids? If so, what solutions/implementations have come about from this if any. There has been talk about putting covers on these trays, but due to ambient temperatures/current going through cables, we feel this could do more harm than good. Any suggestions would be very helpful.

Thank,

AS

 

[iwire]

Maybe stop spraying them with water.

 

[jumper]

Maybe stop spraying them with water.

Patient: "Doctor, it hurts when I do this."

Doctor: " Then don't do that."

 

[iwire]

allowing for faults to occur when the water hits the bad cables.

Kidding aside you have answered your own question.

The cables are bad, beyond their useful life, the correct solution is to replace them keeping the ambient temp and the water in mind when selecting new conductors.

 

[Cow]

Kidding aside you have answered your own question.

The cables are bad, beyond their useful life, the correct solution is to replace them keeping the ambient temp and the water in mind when selecting new conductors.

It also makes me curious if they were sized based on the ambient temp as well? If they are carrying much current I could see that being additive to the already high ambient temp helping to break the insulation down that much faster.