Incand. Mini Strings Blowing Fuses

[jim6918]

In all my years I have never experienced this. I wrap the rails of my split rail fence with strings of red incandescent mini's. On two sections, it takes 7 strings of 100 ct each. I have done this for years and never had a problem plugging the strings end to end. I know this violates the 3 string rule, but it has always worked without issues. The other night I was viewing the house from a hill overlooking my neighborhood, and immediately noticed that one of the sections was not coming on at all. When I drove back down to the house I tested the end of extension from the controller and it had power, so I knew it had to be the fuse(s) in the first string. I didn't want to do surgery while my show was running and cars driving by so I waited to the next morning. I replaced the fuses on the mini plug and all the sections lit up. I did a 5 hour burn in test using the Hardware Utility, twinkling and chasing the lights on that controller. No problems for the full 5 hours. Come show time at 5:30 everything came on normally and that section ran fine until about 8PM when I glanced out and saw that the section was dead. The other section of fence, also with 7 strings, has functioned normally since lights-on on Thanksgiving. Everything is otherwise identical between the sections.

I thought about splitting the 7 strings into two sections with another extension, but not sure if it will correct it.

Any thoughts?

[-klb-]

Unless you have an intermittent short, it should fix it. I have seen where volunteers have stacked up 7 strings end to end, and they work fine when dry. But get them wet, and the fuse will blow.

1st step is to split them up. Then, if one side blows, you now have half as many strings to investigate for shorts.