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Sunday, April 17, 2005
Entropic Storm: Spring Goes Sproing!
This has been an interesting week. Friday night, April the 8th, the buried electrical cable which feeds power to the house shorted out in a coruscating blaze of vaporised copper and ozone (the latter evident throughout the house, even though the short was about ten metres as the cable runs from the entry to the power panel, and around two right angle bends).
Fortunately, the building with the servers has its own independent power substation, so operation of the site wasn't affected, but the house was without power (and, since the oil burner requires electricity, heat and hot water) until Saturday morning, when we ran a "lifeline" cable from an unused 25 amp circuit on the Fourmilab power panel across the driveway to the house. In the picture to the right (click to display an enlargement), that's the grey cable snaking in from the left and disappearing down a grille into the furnace room window, whence it goes down a hallway to connect to the main bus on the power panel.
The following Monday, it was time to dig up the driveway again. I say "again" because, if you follow this chronicle, you'll recall that toward the end of January the water pipe burst, requiring an excavation to dig it up and replace the failed section. Since this was done in the dead of winter the excavation, although filled in, could not be paved over until warm, dry weather arrived. As it happens, that occurred two days before the electrical cable shorted out.
Now, we didn't have to re-open the water pipe hole--this one was all of two metres to the west of it!
Time domain reflectometry had established that the short was about 10 metres from the entry to the house, but there were no drawings anywhere which indicated the precise route of the underground cable. The electricians brought out a gizmo which, I suppose, is kind of a Maxwellian dowsing rod, and after some very ambiguous readings about which I was highly dubious, they made a big X on the pavement and the guy with the jackhammer went at it. Amazingly (to me anyway), the electrical cable was indeed found within one metre of the X (which was in the centre of the rectangular hole at the left of the picture).
Finding the cable is not the same as finding the short of course, so the excavation was continued on the arm which goes right to left until a junction box which was about half melted and half charred was discovered near the end of the branch at the right of the picture. We disconnected the cable inside the house and tried to pull the old cable out from either end to no avail whatsoever--it was put into that conduit when the house was built in 1967, and it is determined to stay there until the end of time.
The most straightforward and economical solution, then, was to dig a new arm on the trench (which goes toward the top of the photo) to the exterior wall of the basement room which holds the heating oil cistern, bore a hole through that wall, and route a new cable through that room to the utility panel in the room which adjoins it. In the enlargement of the picture you can see the PVC conduit through which the cable runs into the house. At the left, the dark grey thing shaped like a skinny rugby ball is the junction box in which the new cable is spliced to the existing feed cable, which appeared to be in fine condition. I was amazed to discover that this 25 A 380 V three phase cable is spliced with crimped connections which are insulated by air--the individual wires are cut so the splices are staggered apart and cannot contact one another. But what if water gets into the junction box, you ask? Well, that's probably what brought this circus to town in the first place! Having had the water fail in January and the electricity blow up in April, I remarked to one of the neighbours, "What next? The air?" I didn't have to wait long to learn my guess was wrong. The morning we began to replace the cable, telephone service for the entire village went down! Miraculously, this was due to a failure which was not beneath my driveway, and about 36 hours later, telephone service was restored. Fortunately, mobile phones continued to work during the land line outage, and the leased line which provides Fourmilab's Internet connectivity was not affected. I don't know about you, but events like this leave me a little punchy--whenever I'm about to dig into a project which will take substantial time and concentration, I find myself looking up
at the sky to see if any anvils or pianos are on incoming trajectories and muttering "What next?" over and over. After devoting most the past week to electricity and telephone problems, I figured nothing really weird was likely to happen this week-end.
Oh well . . . Saturday dawned with weather more like November than April--howling winds, thick fog, and drizzle. Around sunset (not that there was any direct evidence of that event), lightning and thunder arrived in great abundance, along with the usual accompaniment of blinking lights and UPSes reporting momentary outages. Then it started to snow. As I write this, around four on Sunday morning, there's 15 cm of the stuff on the ground (including the roads), and it's continuing to come down as fast as ever. One is tempted to run outside, lift one's countenance to the sky, and shout, "It's the seventeenth of April, for heavens' sake!" While unlikely to make any difference, there may be some satisfaction in registering the protest.
More snow is forecast for tomorrow.
The photo above was taken at 3:06 local time on April 17th. It is a 30 second exposure at f/4 with a 12 mm lens on a Nikon D70 digital camera illuminated by moonlight scattered through the dense clouds and streetlights diffused by snow and fog. I "painted" the trees in the foreground with an LED flashlight during the exposure to highlight them.
Snow continued through the night and, as I post this update at 15:40 on the 17th, continues to fall. The following pictures were taken around 14:45 local "summer" (Hah!) time.
Posted at April 17, 2005 15:42