Saturday, July 05, 2008

It's been a flurry of medium-volatage activity!

I've been doing a ton of medium voltage work lately, and it's GREAT! Continuing with the blow-up story from down at the mill, this is a picture of an old time lead splice. The cable contained an identification strip dated 1951. That's a pretty good lifetime for a cable! This splice will be cut out, and we'll splice in three new cables to the existing 3-conductor lead cable. This is in MH-22.


Backup and I are working on the other end, in MH-24. It's a very small manhole, with just enough room to make the splices. The existing cables in here were three single cables, so the splice is a three single conductor to three single conductor splice, which is pretty common. The day started off very nice, sunny and warm...but it didn't stay that way. Around 6 o'clock, the foreman told me there was a storm coming in from the west. You can't tell from this picture, but basically, since this manhole is sunk below grade, the opening around the manhole acts as a funnel, and every time the safety guy moved up top, gravel or dirt would spill down into the hole. Just before the storm hit, we were at a critical stage in the splice, when the cables, our hands, and the splice components had to stay absolutely clean. Just as we finished heat-shrinking the last of the critical splice components, the storm hit like a tidal wave. Dr. Bob and Junior fought to get the tarps up, to keep rain out of the manhole. They got soaked to the skin in seconds. There were lightning strikes close by, booming thunder almost continuously, and nearly horizontal rain. We joked about a tornado, that we (Backup and I) were safe in the manhole, but not Junior or Dr. Bob, then we heard the Tornado Warning for Wellington come across the radio. It wasn't long before water began pouring into the manhole, right above me. A steady stream of cold water drenched me as I held the cables apart so Backup could work the torch around them. The cables themselves were in just the right place to miss the water, so we were able to continue working on the splice.

The storm lasted about an hour, then the sun broke out again. I fire-taped the cables, and we called it a day.



We had Sunday off, but returned Monday to do the trifurcating splice. Dr. Bob was my partner this time. It was good to work with him again, as he's very knowledgeable about this type of work having done the types of splices in the first picture years ago. Here is the lead cable, with the splice removed, and it's been cleaned up a bit. I did the lead cable prep work, while Dr. Bob prepared the three single conductors. I wanted the experience, since these types of splices don't happen often. I had done this only twice before, and that was years ago.

I'm shrinking the conductive boot over the oil-barrier tubes and lead jacket now.

The cables are ready for the connectors. Notice the triangular shape of the conductors. These are called compact sector conductors, and allow for a smaller over-all diameter of the cable.

One of the major differences with working with lead cables is that the grounding braids and shielding mesh get soldered to the lead jacket. This isn't for the novice. Imagine what would happen if one were to melt through the lead jacket....

Splice complete! The next day, we taped up the cable end connections, chopped up the lead cable and tossed it into a dumpster for the customer, then cleaned up our areas.


After this was over, we went back to the Elastimold job that's been ongoing. Our cut-over was last Saturday (June 28th), and everything went well. Last week Dr. Bob and I did two, 3-conductor armor to 3-conductor armor splices for the folks here:


Starting Monday, we'll be back on the Elastimold job, with the second cut-over scheduled for July 12th. Then I'm going back to the zoo!